PROPULSION PROPULSION PROPULSION PROPULSION. Jurnal Teknik. Technical Journal of Classification and Independent Assurance

ISSN : 977246051300

Jurnal Teknik JurnalBKI Teknik BKI

PROPULSION PROPULSION Technical Journal of Classification and Independent Assurance

Edisi 03 - Agustus 2016

PROPULSION PROPULSION Proporsion and Premilinary Powering

MIssion Requirement COst Estimate

Lines and Body Plan

Damage Stability

Capacity,

Hydrostatic and Bonjean Curve

Floodable Length and Freeboard

Estimasi Kekuatan Lambung Kapal Trim, and Pasca Kerusakan Estimation Of The Ship Hull Intact Strength After Damaged

Stability

FINAL DESIGN

Estimasi Laju Korosi Pada Pelat Ruang Muat Kapal Tanker yang Berlayar Di Perairan Indonesia

Lightship Weight Estimate

Analisa Fatigue Life Pada Bentuk Bracket Lengkung (Radiused Bracket) Topside Module FSO/FPSO Powering

Arrangements (hull and Machinery) Structure

ISSN 2460513

www.bki.co.id

9 7 7 2 4 6 0 513� 00

0

BKI Road to IACS

INTERNATIONAL ASSOCIATION OF CLASSIFICATION SOCIETIES LTD.

Dengan menjadi anggota IACS, BKI akan sejajar dengan badan klasifikasi dunia lainnya dalam supremasi standar rancang bangun dan pengawasan keselamatan kapal di bidang maritim serta meningkatkan kredibilitas armada kapal nasional yang terdaftar dalam klas BKI. “Ini adalah langkah konkret yang dilakukan BKI setelah sekian lama BKI bercita-cita menjadi anggota IACS”. Rudiyanto, Direktur Utama BKI

Biro Klasifikasi Indonesia

Technical Journal of Classification and Independent Assurance

Salam Redaksi,

Bulan Juli 2016 yang lalu, merupakan waktu yang sangat penting bagi BKI, dimana BKI merayakan ulang tahunnya yang ke 52, serta ada satu langkah besar yang dilakukan oleh BKI dalam rangka memperoleh pengakuan di dunia maritim internasional, yaitu proses pendaftaran tahap pertama sebagai anggota IACS (International Association of Classification Society). Tahap pertama ini, maka BKI akan diassessment, diaudit dan proses lainnya sehingga BKI diakui sebagai “Classification Society” oleh IACS. Dalam rangka mendukung langkah besar tersebut, mau tidak mau kegiatan riset yang dilakukan oleh BKI harus lebih ditingkatkan, baik itu internal maupun dengan melibatkan para stakeholder BKI. Untuk menyampaikan kegiatan riset yang dilakukan, maka pada edisi ini, kami berupaya untuk menggabungkan dua hal yang terkait dengan kegiatan penelitian di bidang analisa kecelakaan kapal, energy efficiensi serta system yang ada di kapal. Semoga dengan terbitnya edisi ini, dapat mendorong kemajuan yang signifikan bagi BKI. Kritik dan saran yang membangun serta kontribusi artikel bidang teknik perkapalan, offshore, analisa kecelakaan kapal dan lain lain sangat kami harapkan demi kesinambungan dan kesempurnaan edisi selanjutnya.

Pengarah Penanggung jawab Pemimpin redaksi Anggota

: Direksi BKI : Kepala Divisi Riset dan Pengembangan : Senior Manager Penelitian dan Aplikasi Teknik : Dr. Muhdar Tasrief ALAMAT REDAKSI Siti Komariyah, S.T. Divisi Riset dan Pengembangan Sukron Makmun, S.T. Kantor Pusat Biro Klasifikasi Indonesia Lt. 2 Eko Maja Priyanto, S.T. Jl. Yos Sudarso No. 38 40, Tanjung Priok Gde Sandhyana Pradhita, S.Kom

Jakarta Utara - 14320 Telp. (+62)21 - 4301017, 4301703 ext. 2016 email : [email protected] Jurnal teknik ini dapat diakses melalui website BKI di www.bki.co.id Jurnal Teknik BKI Edisi 02- Desember 2014 Jurnal Teknik BKI Edisi 03-Agustus 2016

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Jurnal Teknik BKI

PROPULSION PROPULSION

DAFTAR ISI

3

Salam Redaksi

5

41

The Collision Accident Of The Indonesian Ro-Ro Car-Passenger Ferry KMP. Bahuga Jaya Versus Singapore Gas Carrier MV. Norgas Cathinka In Sunda Strait Indonesian Innocent Passage

53

Aplikasi BKI-Greenpadma Sebagai Penerapan Regulasi Energi Efisiensi

13

21

31

With the assumption that the optimum propeller rotation is unknown, the conventional method may Estimasi Frekuensi Dengan method not beTubrukan used, hence Kapal the mathematical Menggunakan Metode Samson Selama should be adopted instead. In thisProses study, therefore, the mathematical the lifting Pipeline Decommissiong Padamethod Alur particularly Pelayaran line theory and the principles of vortex lattice Barat Surabaya solution are utilized together in the propeller vortex lattice program developed by Kerwin (2001) which are used to analyse the propeller performance of a ship. Vortex lattice method is generally robust where a lot spacing algorithms do converge to the correct answer (Kerwin, 1986). In the lifting line theory, each blade of Gas the propeller Penilaian Risiko Kebakaran Proses can be considered as a lifting surface with some Liquefaction Pada Unit FLNG distribution of vortex sheet strength. It is then considered for the limiting case of vanishing chord length. The objective is to calculate the circulation distribution along propeller blade radius and hence 67 computing force of a propeller by the vortex lattice solution. Obtaining the force may allow us to get the propeller efficiency and understand in which rotation a propeller will acquire its highest MOP Model To Describe Indonesian Ship Accidents efficiency.

Machine: M2

77 2. Theory Of Computation Media: M3 It has been mentioned in the former section that the lifting line theory and the principle of vortex lattice solution are adopted in the propeller vortex lattice program in order to obtain the distribution Management: of circulations on each propeller blades sections. M4 then be used to compute the These results will forces in the axial and tangential directions. By integrating these forces over the radius 86 and summing up over the number of blades as they are identical, the total propeller thrust and torque may be obtained. The following subsection will describe these problems in sufficiently detail. Man: M1

Figure 4. MOP Model 2.1 Coordinate System and Notation

89

A right-handed coordinate system is adopted to define the propeller coordinate system 93 and Jurnal Teknik BKI notation, with the x-axis coincident with the axis Edisi 02 - Desember of 2014 propeller rotation and y-axis positive upward. The z-axis completes the right-handed coordinate

arer ship ment gers

4

0 a)

Solusi

Studi Pemilihan Metode Platform 61 On The Use Of The Lifting Line Theory For system as shown the following Figure 1. precision the diagrams. Such kinds of Optimizing Decommissioning danin reading Analisa Frekuensi TheinPropeller Performance Of Ship deficiency shallSelama not be encountered in another Tubrukan Kapal Proses available method. Decommissioning

tor becomes factor by the each factor fect to MTS. ers, there are

tion

ISSN : 977246051300

5

Jurnal Teknik BKI 10 15 Edisi 03-Agustus 2016

Man Factor

20

Figure 1. Propeller Coordinate System and

Novel Design Of Notation High Load Capacity Smart Magnetorheological Elastomer Vibration As shown in Figure 1, the propeller is rotating with Isolator In Hybrid Mode angular velocity (𝜔) in a clokwise direction when looking downstream. The axial inflow velocity (𝑉� ) is coming from the negative x-axis, where the origin of the coordinate is in the plane of propeller as a reference point forSistem all axial dimensions of the Gas Rancang Bangun Penginjeksian surface of a propellerDual blade.Fuel Diesel Engine Pada Modifikasi Since a propeller has 𝑍 number of identical blades with maximum radius 𝑅, thus only one blade is considered first for computing the distribution of circulation which is called as a key blade given as green color in Figure 1. This blade and the others are placed on a hub which is attached to a shaft. The hub and Kantor shaft may be considered as an Daftar Alamat axisymmetric body and usually idealized as a PT.cylinder Biro Klasifikasi of radius 𝑟� .Indonesia 2.2 Vortex Lattice Lifting Surface

Daftar Rules & Guideslines BKI

In the lifting line theory, each blade of propeller may be considered as a lifting surface with some of bound and free vortex sheet strength distributed along the Penulisan lifting surface. Bound vortex Pedoman Jurnal Teknik BKI is the portion of the vortex lying along the span and the free vortex or so-called the trailing vortex extending downstream indefinitely (Flood, 2009).

STUDI PEMILIHAN METODE PLATFORM DECOMMISSIONING DAN ANALISA FREKUENSI TUBRUKAN KAPAL SELAMA PROSES DECOMMISSIONING A. A. B. Dinariyana, Ayudhia Pangestu Gusti, Ketut Buda Artana, AA. Masroeri, I Made Ariana, Yeyes Mulyadi Abstract This study addresses the selection of appropriate methods of platform decommissioning and frequency analisys of ship collisions as a result of the decommissioning process. Object of study in this study is a Wellhead Platform that located 35 km from the Northern island of Madura. In early operation the platform was collapsed because the soil where the platform is in an unstable condition. According to this condition, it is planned to move the platform from the initial position to the new coordinates, 755,337.019 mE; 9,268,400 mN. This study discusses the determination of the appropriate platform removal methods, and collision frequency analisys ships that pass around the platform with the ship used to carry out decommissioning platform. There are four alternative decommissioning methods to be used in the analysis namely HLV (Heavy Lift Vessel), SSCV (Semi Submersible Crane Vessel), SLV (Single Lift Vessel), and BTA (buoyancy Tank Assembly). Selection of decommissioning method is performed using AHP (Analytical Hierarchy process). In this study, only crossing collision beetwen regular vessel with transport are considered. The analisys is done using collision model proposed by IWARP. The selesction analysis resulted that using HLV is selected to conduct the commissioning of platform. The selection results of the study show that the method chosen decommissioning platform is a method of HLV (Heavy Lift Vessel). During the decommissioning process, the frequency of regular vessel collision with the barge transport for crossing collision case is at 0.0138 with a collision angle of 300, 0.015 by 900 and 0.0193 with a collision angle 1500. Due to value of frequency is less than 1, it can be concluded that the number of ship collision frequency which may occur during the process of decommissioning platform in case of crossing collision remained at an acceptable level. Keywords : Platform Decommissioning, AHP, Ship Collision Frequency, IWARP

1.

Pendahuluan

jaan pemotongan sebagian atau keseluruhan instalasi dan pemindahan / pengangkutan hasil pembongkaran ke lokasi yang telah ditentukan. Platform removal dan disposal bisa dilakukan dengan cara memotong platform dan dibawa ke darat, atau memotong platform dan dibuang ke laut dalam, kemudian membiarkan platform sebagai rumah ikan. Pada studi ini, platform removal yang dipilih adalah memotong platform dan dibawa ke darat.

O

bjek kajian pada studi ini merupakan Wellhead Platform yang terletak pada koordinat 755,432mE; 9,268,782mN dengan kedalaman laut 57 m. Platform ini dihubungkan dengan kapal FPSO melalui pipa sepanjang 691 m. Dalam kasus ini, platform akan dipindahkan dari koordinat awal ke koordinat baru, yaitu 755,337.019 mE; 9,268,400 mN dikarenakan struktur tanah yang menumpu platform tersebut tidak stabil sehingga mengakibatkan platform berada pada posisi miring. Bangunan atau instalasi lepas pantai yang tidak memenuhi ketentuan atau tidak digunakan wajib dibongkar, sesuai dengan PM. Nomor 68 Tahun 2011 pasal 43 ayat 1.

Platform ini merupakan platform jenis wellhead dengan jenis struktur Fixed Platform. Fixed platform terdiri dari dua bagian, yaitu bagian topside dan bagian jacket. Sehingga proses decommissioning dari platform dilakukan dengan dua tahap. Tahap pertama adalah proses decommissioning bagian topside, tahap kedua adalah decommissioning bagian jacket.

Platform decommissioning adalah menghentikan operasi dari bangunan lepas pantai. Berdasarkan Peraturan Menteri ESDM RI Tahun 2011 tentang Pedoman Teknis Pembongkaran Instalasi Lepas Pantai Minyak dan Gas Bumi pasal 1, pembongkaran adalah peker-

Jurnal Teknik BKI

PROPULSION

Potongan platform yang sudah terpotong akan dibawa menggunakan transport barge dari lokasi

5

Edisi 03-Agustus 2016

Jurnal Teknik BKI


memotong platform dan dibawa ke darat.

menuju

Jurnal Teknik BKI

PROPULSION Platform ini merupakan

barge

platform jenis

wellhead dengan jenis struktur Fixed

PROPULSION

dari

lokasi

Surabaya.

menunjukkan

posisi

decommissioning Gambar dari

1

platform

terhadap pulau Madura.

Platform

Gambar1. 1 :Posisi Posisi platform platform terhadap Gambar terhadapPulau PulauMadura Madura decommissioning menuju Surabaya. Gambar 1 menunjukkan posisi dari platform terhadap pulau Madura. Proses platform decommissioning ini memiliki potensi bahaya berupa tubrukan kapal yang melewati alur terdekat dari lokasi dengan kapal pekerja dan transport barge yang bekerja selama proses platform decommissioning. Tujuan dari studi ini adalah untuk memberikan usulan metode teknologi platform decommissioning yang sesuai dan juga untuk mengetahui tingkat frekuensi tubrukan kapal yang melewati alur terdekat lokasi decommissioning dengan kapal pekerja ataupun transport barge selama proses platform decommissioning berlangsung.

2.

Metode Penelitian

2.1.

Metode Pengujian

Pemilihan metode platform kan dengan menggunakan Hierarchy Proccess). Terdapat decommissioning yang akan Jurnal Teknik BKI Edisi 02 - Desember 2014

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Jurnal Teknik BKI Edisi 03-Agustus 2016

decommissioning dilakumetode AHP (Analytical empat alternatif metode digunakan dalam anali-

sis pemilihan yaitu HLV (Heavy Lift Vessel), SSCV (Semi Submersible Crane Vessel), SLV (Single Lift Vessel), dan BTA (Bouyancy Tank Assembly). Sedangkan untuk analisis frekuensi tubrukan kapal menggunakan model perhitungan frekuensi Quantitative Risk Assessment (QRA) dengan potential hazard berupa Head-on collision. 2.2.

Analytical Hierarchy Process (AHP)

AHP merupakan suatu model pendukung keputusan yang dikembangkan oleh Thomas L. Saaty. Model pendukung keputusan ini akan menguraikan masalah multi faktor atau multi kriteria yang kompleks menjadi suatu hirarki. Hirarki didefinisikan sebagai suatu representasi dari sebuah permasalahan yang kompleks dalam suatu struktur multi level, dimana level pertama adalah tujuan, yang diikuti level faktor, kriteria, sub kriteria, dan seterusnya ke bawah hingga level terakhir dari alternatif. Dengan hirarki, suatu masalah yang kompleks dapat diuraikan ke dalam kelompok - kelompoknya yang kemudian diatur menjadi suatu bentuk hirarki sehingga permasalahan akan tampak lebih terstruktur dan sistematis. Secara garis besar


prosedur AHP meliputi tahapan sebagai berikut: • Dekomposisi Masalah Dekomposisi masalah adalah langkah dimana suatu tujuan yang telah ditetapkan selanjutnya diuraikan secara sistematis kedalam struktur yang menyusun rangkaian sistem hingga tujuan dapat dicapai secara rasional. • Penilaian atau Pembandingan Elemen Apabila proses dekomposisi telah selasai dan hirarki telah tersusun dengan baik. Selanjutnya dilakukan penilaian perbandingan berpasangan (pembobotan) pada setiap hirarki berdasarkan tingkat kepentingan relatifnya. Hasil dari penilaian adalah nilai/bobot yang merupakan karakter dari masing-masing alternatif. Prosedur penilaian perbandingan berpasangan dalam AHP, mengacu pada skor penilaian yang telah dikembangkan oleh Thomas L. Saaty. • Penyusunan Matriks dan Uji Konsistensi Selanjutnya adalah penyusunan matriks berpasangan untuk melakukan normalisasi bobot tingkat kepentingan pada tiap-tiap elemen pada

hirarkinya masing-masing. Pada tahapan ini analisis menggunakan software Expert Choice. Expert Choice merupakan sebuah perangkat lunak yang berfungsi untuk menganalisis hasil dari pembobotan AHP. Software ini mempermudah dalam menilai dan menentukan alternatif yang tepat. • Penarikan Kesimpulan Penarikan kesimpulan dilakukan dengan mengakumulasi nilai yang merupakan nilai sensitivitas masing-masing elemen. Pada tahap ini, sudah terdapat satu alternatif yang terpilih. 2.3.

Analisa Frekuensi

Analisis frekuensi untuk kasus crossing collision ini menggunakan model perhitungan pada IWARP seperti terlihat pada Gambar 2. Crossing collision merupakan keadaan dimana kapal bertubrukan dengan kapal lain karena berseberangan. Pada kasus ini Crossing collision dimungkinkan terjadi antar kapal karena kapal pengangkut platform akan melewati jalur pelayaran untuk membawa platform ke daratan terdekat.

Gambar 2 : Crossing Collision Ship to Ship Jurnal Teknik BKI Edisi 02- Desember 2014 Jurnal Teknik BKI Edisi 03-Agustus 2016

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Jurnal Teknik BKI

PROPULSION PROPULSION Gambar 2. Crossing Collision Ship to Ship

(1)

λ�� = 𝑁� . 𝑃� ��

𝑁�

��

�

(2)

= ∑�,� (��)(��) 𝐷�� 𝑉��

ambar Gambar 2. Crossing 2. Crossing Collision Collision ShipShip to Ship to Ship Gambar 3 : Crossing Collision Diameter

mbar 2.Gambar Crossing2.Collision to ShipShip to Ship CrossingShip Collision

kapal i, Bi merupakan lebar kapal i, Vi merupakan kecepatan kapal i, Lj merupakan panjang kapal j, Bj merupaDilihat pada Persamaan 1 diatas, NG merupakan jumlah kan lebar kapal j, V merupakan kecepatan kapal j, V j ij crossing candidate, sedangkan Pc merupakan λ�� = collision 𝑁� . λ𝑃�� (1) fak- (1)merupakan kecepatan relatif kedua kapal θ merupakan � = 𝑁� . 𝑃� �terjadinya � � �� sudut terjadinya tubrukan. Gambar 4 menunjukkan 𝑁� 𝑁�tor penyebab = ∑=�,�∑(��)(��) 𝐷�� 𝑉 𝐷��tubrukan. 𝑉�� Dibawah ini merupakan (2) (2) �,� (��)(��) �� persamaan untuk mencari nilai dari NG . skenario terjadinya tubrukan antara transport barge dengan kapal yang lewat disekitar lokasi decommissioning. ��

(1) (1)

λ��λ�� = 𝑁 =� .𝑁𝑃�� . 𝑃�

𝑁�

� �� =𝑁�∑ 𝐷�� =∑ �,� (��)(��) �� 𝐷�� 𝑉�� ,�𝑉(��)(��) ��

(2)

(2)

Qi merupakan frekuensi kapal di jalur i selama proses decommissioning, Q j merupakan frekuensi kapal di jalur j selama proses decommissioning, Vi merupakan kecepatan kapal di jalur i, Vj merupakan kecepatan kapal jalur j, Dij merupakan crossing collision diameter, Vij merupakan kecepatan relatif kedua kapal, sedangkan θ merupakan sudut terjadinya tubrukan. Gambar 3 menunjukkan cara untuk mengetahui nilai dari crossing collison diameter yang menggunakan Persamaan 3 dimana Li merupakan fungsi dari panjang

terhadap Kapal padaKapal kasus Crossing Gambar 4 : Posisi Transport Barge terhadap Gambar 4. Posisi Transport pada Barge kasus Crossing Collision Collision

Gambar 3. Crossing Collision Diameter

𝐷�� =

��

Jurnal Teknik BKI Edisi 02 - Desember 2014

8


��

�

sin 𝜃 + 𝐵� �1 − �sin 𝜃 � � � ��

��

60.00% 40.00%

40.60%

��

�

��

28.30%

+ 𝐵� �120.00% − �sin 𝜃 � � � 0.00%

��

19.70%

(3)

11.40%

Metode Decommissioning

HLV

SSCV

SLV

BTA

Gambar 5. Rangking setiap alternatif metode decommissioning

60.00%

49.90%

.


3.

Hasil dan Pembahasan

3.1.

Hasil Pemilihan Metode Platform Decommissioning dengan AHP

60.00%

49.90%

40.00%

17.50% 20.00% 12.10% 9.70% 10.70% Susunan hierarki untuk pemilihan metode platform decommissioning ini mempunyai lima atribut, yaitu 0.00% keselamatan, non teknis, sosial, biaya, dan kelayakan Sub Atribut teknis. Setiap atribut mempunyai minimal dua sub atribut. Keselamatan Non-Teknis Sosial Biaya Teknis terhadap Kapal pada kasus Crossing Dengan menggunakan software expert choice didapatGambar 6 : Rangking setiap atribut metode Posisikan Transport Barge Collision hasil seperti terlihat pada Gambar 5 dan Gambar 6. decommissioning

Gambar 6. Rangking setiap atribut metode decommissioning

Sedangkan Gambar 7 menunjukkan grafik sensitivitas dari keempat alternatif. Analisis sensitivitas bertujuan 60.00% memprediksi keadaan apabila terjadi perubahan yang 40.60% 40.00% cukup besar sehingga berpengaruh terhadap urutan 28.30% 19.70% prioritas dari alternatif. Dengan menggunakan dynamic 11.40% 20.00% sensitivity yang terdapat pada software expert choice, nilai sensitivitas pada setiap atribut dapat diketahui. Dari 0.00% Metode Decommissioning hasil analisis sensitivitas setiap atribut disimpulkan bahwa seberapa besarpun nilai sensitivitas dirubah, HLV SSCV SLV BTA tidak akan berpengaruh terhadap alternatif yang terGambar 5 : Rangking setiap alternatif metode pilih, yaitu HLV tetap di ranking pertama, kemudidecommissioning Gambar 5. Rangking setiap alternatif metode decommissioning an SSCV ranking7.kedua, disusul SLV dan terakhir BTA. Gambar Performance Sensitivity

60.00%

49.90%

40.00% 20.00%

9.70%

0.00% Keselamatan

Non-Teknis

10.70%

17.50%

Sub Atribut Sosial Biaya

12.10%

Teknis

Gambar 6. Rangking setiap atribut metode decommissioning

Gambar 7. Performance Sensitivity

Gambar 7 : Performance Sensitivity

Jurnal Teknik BKI Edisi 02- Desember 2014 Jurnal Teknik BKI Edisi 03-Agustus 2016

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PROPULSION PROPULSION 3.2.

Hasil Perhitungan Frekuensi Tubrukan Kapal Crossing Collision

Kasus tubrukan kapal crossing collision ini melibatkan seluruh kapal yang berada di alur pelayaran Surabaya menuju Indonesia bagian Timur (Makasar dan Jayapura) maupun sebaliknya dengan transport barge yang menuju Pelabuhan Telaga Biru, Madura. Tahap pertama yang dilakukan dalam menghitung frekuensi tubrukan ship to ship crossing collision adalah menentukan faktor-faktor yang berpengaruh pada perhitungan jumlah kandidat tubrukan seperti dimensi kapal, kecepatan kapal, dan jumlah kapal yang berlayar selama proses platform decommissioning. Pada kasus ini, diasumsikan kecepatan dari transport barge 10 knots, sedangkan kecepatan kapal ukuran terbesar adalah 12 knots (Loa = 177,3 meter dan B = 28 meter). Tahap selanjutnya adalah menentukan faktor-faktor penyebab terjadinya tubrukan, seperti failed piloting, failed navigation devices dan failure alerting seperti diperlihatkan pada Gambar 8 dibawah. Pada kasus crossing collision, pemodelan tubrukan dibagi menjadi tiga model. Model pertama untuk kasus crossing collision dengan sudut tubrukan 300, model kedua untuk kasus crossing collision dengan sudut tubrukan 900 dan model ketiga untuk kasus crossing collision dengan sudut tubrukan 1500. Perbedaan sudut dalam pemodelan dimaksudkan untuk mengetahui pengaruh besarnya sudut tubrukan terhadap frekuensi terjadinya crossing collision. Dibawah ini merupakan tabel hasil perhitungan frekuensi crossing collision untuk setiap pemodelan.

Tabel 1 : Hasil Perhitungan Crossing Collision dengan θ=30°

Lama Pengerjaan

A

Human Eror

B

Wrong appreciation of traffic information

C

80.10%

80.00% Wrong appreciation of traffic information 0.50% Failure in ship’s technical systems

Probability Factors 0.04%

Failed Nav. Devices 6.17%

Failure Alerting

5.70%

Failure in communication 0.50%

0.76%

Gambar 8 : Fault Tree Analysis untuk kasus crossing collision Jurnal Teknik BKI Edisi 02 - Desember 2014

10


= (A + B) - (A x B)

80% 0.50% 80.100%

D

Failed Technical System

5.70%

E

Failed Communication

0.50%

F G H

Failed Navigation Devices = (D + E) - (D x E) Failure Alerting Prob. Collision/Passing =CxDxE

6.17% 0.76% 0.04%

I

Speed Vessel (A) in m/s

5.14

J

Speed Vessel (B) in m/s

6.17

K

Relative speed between the vessel (Vij) in m/s

3.09

L

Collision Diameter (Dij) in m

M

Number of passage per year in line 1 (Q1) in unit per year

4

N


179

O

Number of Collision candidate (NG), in ship per year

37

P

Crossing Collision fequency in collisions / year

0.0138

Human Failure Failure Piloting

Failed Piloting

31 Hari

262.41


Tabel 2 : Hasil Perhitungan Crossing Collision dengan θ=90° dan θ=150°

Lama Pengerjaan

A B C

Human Eror Wrong appreciation of traffic information Failed Piloting = (A + B) - (A x B)

31 Hari

Lama Pengerjaan

80%

A

0.50%

B

80.10%

C

31 Hari 80%

Human Eror Wrong appreciation of traffic information Failed Piloting

0.50% 80.10%

= (A + B) - (A x B)

D


5.70%

D


5.70%

E


0.50%

E


0.50%

6.17%

F

0.76%

G

0.04%

H

F G H

Failed Navigation Devices = (D + E) - (D x E) Failure Alerting Prob. Collision/Passing =CxDxE

Failed Navigation Devices = (D + E) - (D x E)

6.17% 0.76%

Failure Alerting Prob. Collision/Passing =CxDxE

0.04%

I


5.14

I


5.14

J


6.17

J


6.17

K


8.04

K

L


219.76

L


M


4

M


4

N


179

N


179

O


40

O


51

P


0.0150

P


0.0193


10.94 104.37


11

Jurnal Teknik BKI

PROPULSION PROPULSION Seperti diperlihatkan pada Tabel 1 dan Tabel 2 tentang hasil perhitungan frekuensi untuk kasus crossing collision dengan sudut tubrukan 300, 900, dan 1500, dapat diketahui nilai frekuensi adalah kurang dari 1, yang berarti bahwa proses pemindahan platform selama proses decommissioning platform untuk semua pemodelan masih dapat diterima.

4.

Kesimpulan

Berdasarkan analisis yang telah dilakukan, metode platform decommissioning yang terpilih adalah HLV (Heavy Lift Vessel). Sedangkan hasil perhitungan frekuensi menunjukkan untuk kasus crossing collision tingkat frekuensi tubrukan bernilai 0,0138 untuk sudut tubrukan θ=300, 0,015 untuk sudut tubrukan θ=900, dan 0,0193 untuk sudut tubrukan sebesar θ=1500, dimana nilai-nilai tersebut berada dibawah 1, yang berarti bahwa proses pemindahan platform selama proses decommissioning platform untuk semua pemodelan masih dapat diterima.

5.

Daftar Pustaka

Andresen, Johan.F (2004). Decommissioning of Offshore Platforms Utilizing Cost Effective Single Lift Technology. Stavanger, Norway. Artana, KB (2009). Penilaian Risiko Pipa Gas Bawah Laut Ujung Pangkah-Gresik Dengan Standard DNV RP F107. Surabaya.

Artana, KB ; Dinariyana, A.A.B ; Ariana, I.M ; Sambodho, Kriyo, S. (2013). Penilaian Risiko Pipa Gas Bawah Laut.. Surabaya : Guna widya. Axon, S (2015). Stamford Decommissioning Comparative Assessment. UK. BP (2005). North West Hutton Decommissioning Programme. US : BP Press. CNR International (2013). Murchison Decommissioning Comparative Assessment Report. UK. DNV-RP-F107 (2010). Risk Assessment of Pipeline Protection. Dr. Robert C. Byrd, PE, Donald J. Miller, dan Steven M. Wiese (2014). Cost Estimating for Offshore Oil & Gas Facility Decommissioning. US. Ekins, Paul (2005). Decommissioning Of Offshore Oil And Gas Facilities. Policy Studdies Institute. Friis-Hansen, Peter (2008). IWRAP Mk II, Basic Modelling Principles for Prediction of Collision and Grounding Frequencies, (draft working document), Rev. 4. Technical University of Denmark. Kristiansen, Svein (2005). Maritime Transportation: Safety Management and Risk Analysis. DNV Technica. Offshoreenergy.dk (2013). A Danish Field Platforms and Pipelines Decommissioning Programmes. Denmark. Peraturan Menteri Perhubungan nomer 68 (2011). Alur Pelayaran Laut. Peraturan Menteri Energi Dan Sumber Daya Mineral Nomer 01 (2011). Pedoman Teknis Pembongkaran Instalasi Lepas Pantai Minyak Dan Gas Bumi. Swiss Association of Concrete Drilling and Cutting Enterprises (2007). Technical Manual for Construction Cutting Specialists. Bellach, Switzerland.

Prof. Dr. Ketut Buda Artana, ST, MSc, Staf Pengajar Jurusan Teknik Sistem Perkapalan Fakultas Teknologi Kelautan ITS, [email protected] nomer 68 (2011). Alur Pelayaran Laut. 14. Peraturan

Menteri

Energi

Dan

Sumber Daya Mineral Nomer 01 (2011).

Pedoman

Teknis

Pembongkaran Instalasi Lepas Pantai Minyak Dan Gas Bumi. 15. Swiss 12. Offshoreenergy.dk (2013). A Danish Field

Platforms

Decommissioning

and

Pipelines

Programmes.

Denmark.

Prof. Dr. Ketut Buda Artana, ST, MSc, Staf Pengajar Jurusan Teknik Sistem Perkapalan Fakultas Teknologi Prof.Kelautan Dr. KetutITS, [email protected] Artana, ST, MSc,

Association

Drilling and (2007).

Construction

of

Concrete

Cutting Enterprises

Technical Cutting

Manual

for

Specialists.

Bellach, Switzerland.

13. Peraturan Menteri Perhubungan

Ayudhia Pangestu Gusti, menempuh pendidikan S1 Jurusan Teknik Sistem Perkapalan, Fakultas Teknologi Kelautan, Institut Teknologi Sepuluh Nopember (ITS). Penulis mengambil bidang Reliability, Availability, Mantainability and Safety di jurusan Teknik Sistem Perkapalan untuk pengerjaan tugas akhir dengan judul ”Analisis Risiko Terhadap Proses Decommissioning Platform”. [email protected] Staf Pengajar Jurusan Teknik Sistem Perkapalan FakultasAlurTeknologi nomer 68- (2011). Pelayaran Laut. Kelautan ITS, [email protected]

14. Peraturan

Menteri

nomer 68 (2011). Alur Pelayaran Laut.

Energi

Dan

Sumber Daya Mineral Nomer 01 Menteri Energi Dan

14. Peraturan

(2011). Sumber Daya MineralPedoman Nomer 01 (2011). Pedoman Pembongkaran

Teknis

Teknis Instalasi Lepas Pantai

Pembongkaran Instalasi Lepas Pantai

Minyak Dan Gas Bumi.

Minyak Dan Gas Bumi.

15. Swiss

15. Swiss

12. Offshoreenergy.dk Danish 12. Offshoreenergy.dk(2013). (2013). AA Danish Platforms and and FieldFieldPlatforms Decommissioning

Decommissioning Denmark.

Pipelines Pipelines

Programmes.

Programmes.

Denmark. 13. Peraturan Menteri Perhubungan

Association

Association

of

of

Concrete

Concrete

Drilling and Cutting Drilling and Cutting Enterprises Enterprises (2007). Technical Manual (2007). Technical

for Manual

for

Construction

Cutting Specialists. Construction Cutting Specialists.



Ayudhia

Pangestu

Gusti,

menempuh

pendidikan S1 Jurusan Teknik Sistem Perkapalan, Fakultas Teknologi Kelautan, Institut Teknologi Sepuluh Nopember (ITS). Penulis mengambil bidang Reliability, Availability,


Prof. Dr. Ketut Buda Artana, Staf Pengajar Jurusan Teknik Sistem Perkapalan - Fakultas Teknologi Kelautan ITS. [email protected]

Ayudhia

Pangestu


Gusti,

menempuh


Ayudhia

12

Pangestu

Gusti,

Jurnal menempuhTeknik BKI Edisi 03-Agustus 2016


A.A. Bgs. Dinariyana Dwi Putranta, Staf Pengajar Jurusan Teknik Sistem Perkapalan - Fakultas Teknologi Kelautan ITS, [email protected] , [email protected]

ESTIMASI FREKUENSI TUBRUKAN KAPAL DENGAN MENGGUNAKAN METODE SAMSON SELAMA PROSES PIPELINE DECOMMISSIONG PADA ALUR PELAYARAN BARAT SURABAYA Ketut Buda Artana, Emmy Pratiwi, A.A.B. Dinariyana, AA. Masroeri, I Made Ariana, Yeyes Mulyadi Abstract Surabaya West Access Channel (SWAC) is one of the busiest shipping channels in Indonesia. Currently, with the depth of shipping channel - 9m LWS and width 100 m, large vessels with depper draft can not pass the channel. In order to increase the amount of cargo carried by larger vessels and to decrease logistic costs, PT. Pelindo III plans to revitalise the channel. The shipping channel will be deepened to - 16 m LWS and also be widened to 200 m. The revitalization project can not be conducted until subsea gas pipelines relocation process in the shipping channe is completed. One hazard that may occur during pipeline decommissioning process is regular ships collision to Diving Support Vessel (DSV) and pipelay barge that operated during the process. Hence, this study aims to proposed method of pipeline removal and also to determine the frequency of ships collision that pass DSV and pipelay barge during pipeline decommissioning process. There are two alternative methods of pipeline removal considered in this study namely, Reverse S-Lay and Cut & Lift. The selection is carried out using the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), while the collision frequency is calculated using SAMSON Model that originally proposed by MARIN, Netherlands. TOPSIS selected Reverse S-Lay as a method for decommissioning the subsea gas pipelines. During the process of decommissioning pipeline with a Reverse S-Lay, the annual frequency of powered and drifting collisions are 0.0153 and 0.00511 respectively. Due to the value of annual frequencies are less than unity (1) for both collision scenarios, it can be concluded that the risks due to collisions during decommissioning pipeline are acceptable. Keywords : Pipeline Decommissioning, Ship Collision, TOPSIS, SAMSON Model

1.

Pendahuluan

A

lur Pelayaran Barat Surabaya (APBS) merupakan salah satu akses laut menuju wilayah Timur Indonesia khususnya di Pelabuhan Tanjung Perak, Surabaya. APBS yang saat ini memiliki kedalaman sekitar -9 Low Water Spring (LWS) dengan lebar 100 meter masih belum bisa menampung kapal-kapal dengan draft yang tinggi sehingga arus barang dapat terkendala. Karena kondisi APBS yang seperti ini, PT. Pelindo III akan melakukan revitalisasi dengan mendalamkan alur hingga nantinya APBS memiliki lebar 200 meter dan kedalaman -16 mLWS. Dengan adanya revitalisasi ini maka APBS dapat digunakan untuk two way traffic atau lalu lintas dua arah dan kapal dengan generasi baru dengan draft yang lebih tinggi dapat melewati APBS. Hal ini akan berdampak pada penurunan biaya logistik dan kelancaran arus barang di Pelabuhan Tanjung Perak. Selain itu dengan revitalisasi ini diperkirakan jumlah

Jurnal Teknik BKI

PROPULSION

kapal dan arus bongkar muat di Pelabuhan Tanjung Perak dapat meningkat hingga 4 sampai 5%. Proses revitalisasi APBS terus dilakukan namun masih belum bisa berjalan dengan baik akibat adanya pipa yang melintang di crossing II di KP (Kilometer Point) 44-46 APBS. Pipa ini terpendam dan berada di kedalaman minus 2 – 2,3 meter dibawah seabed. Pada analisis yang telah ada sebelumnya, apabila pengerukan alur ini dilakukan, maka pipa pada crossing II ini bisa muncul ke dasar laut. Oleh karena itu, untuk menyelesaikan pengerukan APBS secara cepat, maka pemindahan pipa perlu dilakukan. Direncanakan pipa akan dipotong dari masing-masing ujung crossing sepanjang 200 meter, sehingga seluruh pipa sepanjang 2900 meter ini dapat dipindahkan seluruhnya. Posisi pipa pada crossing II di alur ini dapat dilihat pada Gambar 1.

13


Jurnal Teknik BKI


Jurnal Teknik BKI

PROPULSION PROPULSION Langkah :1Menghitung bobot atribut dan sub atribut dengan pairwise Langkah Langkah 1 :1Menghitung : Menghitung bobot bobot atribut atribut dan dan sub atribut sub atribut dengan dengan pairwise pairwise matrix comparison sebelum memulai prosedur TOPSIS matrix matrix comparison comparison sebelum sebelum memulai memulai prosedur prosedur TOPSIS TOPSIS

Langkah :2Menghitung solusi ideal positif dan solusi ideal negatif Langkah Langkah 2 :2Menghitung : Menghitung solusi solusi ideal ideal positif positif dan dan solusi solusi ideal ideal negatif negatif dan separation dan dan separation separation

Langkah Langkah Langkah 3 :3Merangking :3Merangking : Merangking alternatif alternatif alternatif terbaik terbaik terbaik yang yang yang berjarak berjarak berjarak terpendek terpendek terpendek terhadap solusi ideal positif dan berjarak terjauh dengan solusi ideal negatif terhadap terhadap solusi solusi ideal ideal positif positif dan dan berjarak berjarak terjauh terjauh dengan dengan solusi solusi ideal ideal negatif negatif

Gambar 2 : Langkah-langkah Perhitungan TOPSIS 2.2.

Analisis Frekuensi

Perhitungan frekuensi tubrukan kapal dengan kapal yang beroperasi selama pipeline decommissioning pada proses pemindahan pipa ini menggunakan model SAMSON (Safety Assessment Models for Shipping and Offshore in the North Sea) yang dipublikasikan oleh MARIN (Maritime Reseach Institute Netherlands). Gambar 1. Posisi Pipa pada Crossing II di Alur Pelayaran Barat Surabaya

Gambar 1 : Posisi Pipa pada Crossing II di Alur Pelayaran Barat Surabaya Tujuan dari studi ini adalah untuk Proses pemindahan pipa atau pipeline potensi

memberikan usulan metode teknologi

bahaya berupa tubrukan kapal-kapal

pemindahan pipa yang sesuai dan juga

decommissioning

memiliki

yang melewati APBS dengan Diving Proses pemindahan pipa

untukpipeline mengetahui decommissioning frekuensi tubrukan atau kapal-kapal yang melewati APBS Support Vessel (DSV) dan pipelay barge memiliki potensi bahaya berupa tubrukan kapal-kapal yang bekerja selama proses tersebut. yang melewati APBS dengan Diving Support Vessel (DSV) 2 dan pipelay barge yang bekerja selama proses tersebut. Tujuan dari studi ini adalah untuk memberikan usulan metode teknologi pemindahan pipa yang sesuai dan juga untuk mengetahui frekuensi tubrukan kapal-kapal yang melewati APBS dengan DSV ataupun pipelay barge selama proses pipeline decommissioning.

2.

Tinjauan Pustaka

2.1.

Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS)

TOPSIS adalah salah satu metode yang digunakan untuk pengambilan keputusan multikriteria dimana alternatif yang terpilih harus mempunyai jarak terdekat dari solusi ideal positif, dan terjauh dari solusi ideal negatif. Secara garis besar, langkah-langkah dalam perhitungan TOPSIS seperti pada Gambar 2 berikut :


14


2.2.1. Drifting Collision Drifting Collision adalah suatu kejadian yang tidak bisa dihentikan oleh crew kapal yang disebabkan karena kapal mengalami kerusakan mesin sehingga menyebabkan kapal menyimpang dari alur. Setelah kegagalan pada mesin, kapal mulai bergerak menyimpang dengan kecepatan tertentu (drift velocity) tergantung dari kondisi lingkungan seperti kecepatan udara dan arus. Kapal ini dapat menabrak objek lain apabila kapal mengarah ke objek dan kapal tidak bisa memperbaiki kerusakan mesin pada waktu tertentu. Berikut ini prosedur untuk menentukan jumlah kapal yang mengalami drifting dan menabrak objek : a. Menentukan danger part dari link Langkah yang pertama adalah menentukan pada bagian link yang mana kapal akan menabrak objek ketika mesin kapal gagal sesuai dengan arah angin (drift direction). Bagian link inilah yang disebut dengan danger part dari link, lihat pada Gambar 3. Jarak titik kapal ke objek (r(x)) mempengaruhi waktu drifting setelah kecepatan drifting diketahui. b. Drifting velocity Pada model ini, drift velocity pada kapal i dengan arah angin mengikuti Beaufort class b dihitung dengan persamaan 1.


Langkah terakhir untuk menentukan jumlah kapal yang akan menabrak objek adalah dengan dengan mengalikan peluang engine failure ini dengan kegagalan emergency anchor (PAF ), jumlah kapal yang lewat (N) dan breakdown frequency, maka frekuensi tubrukan kapal akibat drifting dapat diketahui. 2.2.2. Powered Vessel atau Ramming Collision Ramming collision dengan objek tertentu disebabkan adanya navigational error atau human error. Berikut ini langkah-langkah dalam menentukan ramming collision :

Danger Part

Gambar 3. 3 Danger Part Gambar : Danger Part (Sumber : MARIN, Contact Drift Model) ( Sumber : MARIN, Contact Drift Model )

Kecepatan drifting dihitung berdasarkan vb adalah wind velocity untuk Beaufort class b, ρair density udara, ρw density air, ALin adalah permukaan lateral udara pada kapal i saat kondisi berbeban n, Li merupakan panjang kapal I, Tin ialah sarat kapal i pada kondisi berbeban n, ςb atau significant wave amplitude diasumsikan dihasilkan untuk Beaufort class b, cdwind dengan nilai asumsi 0,9 adalah koefisien permukaan lateral angin kapal, cd sebesar 0,8 untuk semua tipe kapal adalah koefisien gesekan lateral pada body yang tercelup air, wave drift coefficient atau R dan g merupakan gravity constant. �

�

�

�

� � � ��

�� + �� 2 𝑣 � + = � �� 𝑣�� =� 𝑣��

� ��

�

�

� ��

� ��

(1)

� ��

Setelah diketahui kecepatan drifting kapal dan jarak drifting dari titik kapal ke objek yang akan ditubruk, maka waktu yang diperlukan untuk mencapai objek tersebut 𝑡 > 𝑡𝑠) = 1𝑃�� (𝑡kapal > 𝑡𝑠)menubruk =untuk 1 t ��𝑃�� (𝑡 >�𝑡𝑠) t �> 0.25 untuk 0.25 (3) 𝑡 > �𝑡𝑠) = = �� + �+ �.�(�� .�(�� .��)� � dari ts, maka kapal (1) 𝑣�� =�.��)� 𝑣 = � �� tuk 𝑣 perbaikan mesin lebih lama tidak � � � � � � � � � � � � � � � �� akan mampu menghindari DSV atau laybarge sehingga � � �� Peluang �� tertabrak. � ��menubruk � �� kapal objek �+ = � �� kapal 𝑣 + (1)ini � 𝑣��dapat = 𝑣 � � �� dihitung dengan persamaan 2 dan 3. �

�

� ( )𝑑𝑥∫� � 𝑃�� (𝑥 )𝑑𝑥 𝑃�� 𝑃 = >∫�𝑡𝑠) 𝑃�� untuk t < 0.25 =�� 1 𝑥= 𝑡 > 𝑡𝑠) = 1𝑃�� (𝑡 untuk t < 0.25 � �

(4) (2)

� titik batas � xtitik dan batas x2 adalah dari partdari 1 dan 2𝑃adalah t >danger 0.25 part > 1𝑡𝑠) =untuk t >danger 0.25 untuk (3) 𝑡an>x𝑡𝑠) = xDengan �� (𝑡 �.��)� �.�(�� .��)� � �.�(�� 𝑡 > 𝑡𝑠) = 1𝑃�� (𝑡 > 𝑡𝑠) =untuk t < 0.25 (2) 1 untuk t < 0.25

Kapal hanya akan menabrak objek ketika berada di daerah �

(3) 𝑡 > 𝑡𝑠) = 𝑃�� (𝑡 > 𝑡𝑠) =untuk t >� 0.25 untuk t > 0.25 �.�(�� .��)� bahaya dari link,� jadi hanya diantara x dan x saja. Sehing�.�(�� .��)� �

1

2

ga�� dengan persamaan 2 atau 3 diatas 𝑁 = ∑�� 𝑁𝑠ℎ𝑖𝑝 𝑥 𝑃�� = ∑�mengintegrasikan 𝑃�� 𝑃�� 𝑥 𝑃�� (5) �𝑥 𝑁 𝑠ℎ𝑖𝑝𝑥𝑥𝑃𝑃 �� 𝑥 �� ( ) ( ) 𝑃 = 𝑃 𝑥 𝑑𝑥 𝑃pada = 𝑃 (4) 𝑥 𝑑𝑥 ∫ ∫ titik x dan x akan memberikan total kemungkinan �� 1 2 �

terjadinya drifting :

x2 adalah titik batas adalah xtitik batas dari danger partdari danger part an x1 dan x2Dengan �1 dan �� (𝑥 )𝑑𝑥 𝑃�� = ∫� � 𝑃�� (4) (𝑥 )𝑑𝑥 𝑃 = 𝑃 ∫ �� ∝� ( 𝑃�� (𝑟,titik 𝑃dari (6) 𝐿) batas = 𝑒adalah 𝑟,titik 𝐿) =part 𝑒 �∝� danger part. �� danger adalah an x1 dan x2Dengan dengan x22 adalah titikbatas batasdari dari danger part xx11 dan

𝑁�� = ∑𝑥 𝑃�� 𝑥 𝑃�� = ∑�� 𝑁𝑠ℎ𝑖𝑝 𝑥 𝑃�� 𝑃�� (5) � 𝑁 𝑠ℎ𝑖𝑝𝑥𝑥𝑃𝑃 �� 𝑥 �� (�) �� (�) 𝑑𝑥𝑁 ∫� 𝑒 � 𝑑𝑥 (7) 𝑅𝑂 = 𝑃�� 𝑁 ∫�𝑅𝑂𝑒= 𝑃��

�

= ∑�� 𝑁𝑠ℎ𝑖𝑝 𝑥 𝑃�� 𝑃�� (5) 𝑁�� = ∑𝑥�� 𝑁 𝑃�� 𝑥 𝑃�� 𝑠ℎ𝑖𝑝𝑥𝑥𝑃𝑃 �� 𝑥

a. Danger Part Perhitungan danger part pada ramming model sama dengan drifting model. Yang membedakan hanya pada arah kemana kapal akan melaju. Pada ramming model, tubrukan kapal karena gagal navigasi dapat menyebabkan kapal berubah arah ke 7 sudut mulai dari -30⁰ hingga 30⁰ dengan interval 10⁰ seperti pada Gambar 4. Masing-masing perubahan sudut memiliki nilai probabilitas yang berbeda yakni Gambar 3. Danger Part 0,05 ; 0,1 ; 0,2 ; 0,3 ; 0,2 Contact ; 0,1 ;Drift 0,05. (Sumber : MARIN, Model)

(1)

(2) (3) (1) (1)

Gambar 4 : Ram-Direction yang Berbeda (4) ( Sumber : MARIN, Contact Ram Model ) (2) 2

b. Avoidance (3) function Avoidance (2) function atau sama dengan repair function pada contact drift model digunakan untuk mengeta(3) hui apakah kapal dapat menghindari tubrukan atau tidak (5) yang tergantung dari panjang (ukuran) kapal dan (4) distance. Kapal yang besar akan memramming butuhkan waktu yang lebih lama untuk mengubah arahnya jika dibandingkan dengan kapal kecil, sehing(4) ga kemungkinan untuk menghindari tubrukan adalah (6) kombinasi dari ramming distance (r) dan ukuran kapal

(5) (7) (5)

Jurnal Teknik BKI Edisi 02- Desember 2014


15

�

�

(𝑡 untuk t >part 0.25 >x2𝑡𝑠) = titik 𝑃x=�� untuk t >dari 0.25 >x𝑡𝑠) dan adalah batas danger Dengan 1x titik batas dari danger part an 1 dan 2 adalah �.�(�� .��)� � �.�(�� .��)� � Jurnal Teknik BKI

PROPULSION �

(𝑥 )𝑑𝑥 �� 𝑃�� = ∫� 𝑃𝑃�� = ∫�� 𝑃�� (𝑥 )𝑑𝑥 � 𝑁𝑠ℎ𝑖𝑝 𝑥 𝑃�� 𝑥 𝑥𝑃�� 𝑥��𝑃�� =��x∑= 𝑃= 𝑥𝑃𝑃batas �x �� 𝑁∑ �� 2𝑥 (𝑥part )𝑑𝑥 (𝑥𝑃dari )∫ 𝑃�dan 𝑃 adalah danger an 𝑃𝑠ℎ𝑖𝑝 𝑑𝑥 ∫ 1 �dan x2 = adalah dari danger Dengan x�1titik �� batas �� titik � �

PROPULSION Gambar 4. Ram-Direction yang Berbeda (Sumber : MARIN, Contact Ram Model)

b)

dari ramming distance (r) dan ukuran

Avoidance function

(3)

(3) 𝑁�� = ∑�� 𝑁𝑠ℎ𝑖𝑝 𝑥 𝑃�� 𝑥 𝑃�� 𝑥 𝑃��

(4) (5) (5) (4) part

(4) (4)

�

𝑃�� (𝑟, 𝐿) = 𝑒 �∝�

Avoidance function atau sama dengan

(L)xdengan ∝ (dimensionless) danger ∝ yakni x2batas adalah titik batas part dari danger partmeasure Dengan x2 adalah titik dari danger n x1 dan 1 dan (nilainya 0,1) :

kecocokan dan nilai preferensi antar atribut maupun �(�) � atribut didapatkan dari kuisioner yang diisi oleh respon𝑅𝑂 = 𝑃�� 𝑁 ∫� � 𝑒 �� 𝑑𝑥 � den yang sekiranya paham terhadap bidang ini. Penilaian � �∝��𝑒 �∝� ( ) 𝑃 (6) 𝑟, 𝐿 = ( ) 𝑃 (6) 𝑟, 𝐿 = 𝑒 = ∑�� 𝑁𝑁𝑠ℎ𝑖𝑝 𝑥 𝑃 𝑥 𝑃 (5) �� ∑ = 𝑁 𝑥 𝑃 𝑥 𝑃 𝑥 𝑃 (5) �� kepentingan ini menggunakan pairwise comparison. �� 𝑠ℎ𝑖𝑝 �� . salah satu hasil perhitungan yakdari PHIT dengan jum- Gambar ∑�� 𝑁𝑠ℎ𝑖𝑝 𝑥integral 𝑃�� 𝑥 𝑃�� (5) 5 menampilkan = ∑𝑁 𝑁𝑠ℎ𝑖𝑝 𝑥=Dengan 𝑃�� 𝑥mengalikan 𝑃𝑥 𝑃�� (5) �� 𝑃𝑥 𝑁�� = 𝑁𝐸𝑅 𝑥 𝑅𝑂 lah kapal lewat di alur serta Probabilitas ni bobot untuk semua atribut. �(�) �(�)) yang �( �N �� 𝑑𝑥 � 𝑑𝑥 𝑒 𝑅𝑂𝑃�� = kapal 𝑃�� ∫ 𝑁 ∫� 𝑁 𝑒 (7) (7) 𝑅𝑂 = menabrak objek dari titik tertentu sepanjang �� Technical Feasibility � � �∝� adanya navigational �∝� danger error (6) pada 𝑃�� (𝑟,part 𝐿) =akibat 𝑒𝑃 (6) �� (𝑟, 𝐿 ) = 𝑒 arah Ψ (PRAM ) maka�Ramming Oportunities (RO) karena Cost � � 𝑃�� (6) 𝑟, 𝐿) =: 𝑒 �∝� 𝑃�� (𝑟, 𝐿) =error (6) 𝑒 �∝(adalah navigational repair function pada contact drift model digunakan untuk mengetahui apakah

kapal (L) dengan

kapal dapat menghindari tubrukan atau

yakni

tidak yang tergantung dari panjang

(ukuran) kapal dan ramming distance. Kapal yang besar akan membutuhkan

(dimensionless) danger measure (nilainya

waktu yang lebih lama untuk mengubah

0,1)

:

arahnya jika dibandingkan dengan kapal kecil,

sehingga

kemungkinan

(5)

(6)

(7)

untuk

menghindari tubrukan adalah kombinasi

�

𝑃�� (𝑟, 𝐿) = 𝑒 �∝�

(6)

part akibat adanya navigational error

Dengan mengalikan integral dari 𝑃��

pada arah Ψ (𝑃�� )maka Ramming

dengan jumlah kapal (N) yang lewat di alur serta Probabilitas kapal menabrak

Oportunities (RO) karena navigational

objek dari titik tertentu sepanjang danger

error adalah :

�

�(�) �

𝑅𝑂 = 𝑃�� 𝑁 ∫� � 𝑒 ��

2

𝑑𝑥

(7)

�(�)

�� 𝑁�� = 𝑥 𝑅𝑂�� 𝑁𝐸𝑅 𝑥�𝑅𝑂 𝑁= 𝑒 𝑁𝐸𝑅 𝑑𝑥 𝑅𝑂 𝑁 =�� 𝑃�� ∫𝑅𝑂 �� = 𝑃�� 𝑁 ∫� 𝑒

𝑅𝑂 =

�

�(�) �

𝑑𝑥

�(�) �� (�) � �� 𝑑𝑥 �𝑁𝑑𝑥 𝑒 mengalikan 𝑅𝑂 𝑁 ∫�=� 𝑃 𝑒�� 𝑃��Langkah ∫�adalah terakhir � �

(8) (8) (7)

(7) Ramming OporTechnical Feasibility Technical Feasibility tunities (RO) dengan kemungkinan terjadinya navigational error untuk tipe dan ukuran kapal tertentu.

𝑁�� = 𝑁𝐸𝑅 𝑥 𝑅𝑂 Cost Cost𝑥 𝑅𝑂 𝑁�� = 𝑁𝐸𝑅

𝑁�� =𝑁𝑁𝐸𝑅 𝑥 𝑅𝑂= 𝑁𝐸𝑅 𝑥 𝑅𝑂 ��

0.268 (7) 0.072 0.110

(8)

(8)

Societal

(7) 0.137

0.000

0.200

(8)

(8)

Environment

0.412

0.400

0.600

Safety

Gambar Bobot Atribut Gambar 5 4. : Bobot Atribut

Bobot maupun atribut dan 3 (8) masing-masing sub atribut

Societal Societal Technical Feasibility Technical Feasibilitynilai preferensi dari hasil kuisioner akan menjadi data in-

Nram = Jumlah tubrukan kapal 0.137 7 0.268 NER = Navigational Technical Error Rate (0,65 Feasibility x 10-4 Technical Feasibility 0.268 Environment Environment Cost 2 0.110 Cost 10 0.412 untuk setiap kapal) 0.412 Cost Safety Cost Safety Societal Societal 0.200 0.600 0 0.400 0.600 3. 0.400 Metodologi 7 0.137 4. Bobot Atribut Societal Gambar Gambar 4. Bobot Atribut Societal 0.268 Environment Environment Pada studi0.268 ini, analisis frekuensi tubrukan kapal sela0.072 0.1370.110 710 0.412 decommissioning dipengaruhi oleh 0.412 0.268pipeline 0.268ma proses Environment Environment 3 Safety Safety yang dipakai seperti durasi 0.110 3pipeline removal 10 0.072metode 000 0.400 0.600 0.412 0.412 0.200 0.400 0.600 proses pengerjaan, teknis pekerjaan, skenario posiSafety Safety Gambar 4. Bobot Atribut4. Bobot si kapal yang beroperasi dan lain-lain. Alternatif metode Gambar Atribut 0.200 0.400 0.600 0 0.400 0.600

put dalam perhitungan TOPSIS untuk memilih metode pemindahan pipa yang paling sesuai. Dengan melakukan langkah-langkah perhitungan seperti pada persamaan 1 sampai 5, maka metode yang terpilih adalah reverse S-Lay dengan nilai sebesar 0,61 sedangkan cut and lift hanya mendapatkan nilai 0,39. Hasil pehitungan ini dapat dilihat pada Gambar 6 berikut.

pemindahan pipa yang ditawarkan ada dua macam,

Gambar 4. Bobot Atribut Gambar 4. Bobot Atribut yakni Reverse S-Lay dan3 Cut and Lift. Alternatif ini akan 3

Gambar 5. Hasil Pemilihan Metode Pemindahan Pipa dengan TOPSIS

Gambar 6 : Hasil Pemilihan Metode Pemindahan Pipa dipilih salah satu yang paling sesuai dengan metode dengan TOPSIS 3 for Order 3of Preference by Similarity to Ideal Technique Pipadari dengan Expert Choice didapatkan perhitunSolution (TOPSIS). Setelah motode pipeline removal terpi- Untuk menverifikasi hasil yang Pemindahan lih, maka selanjutnya skenario pemindahan pipa dikem- gan TOPSIS, pemilihan metode pemindahan pipa juga bangkan sebagai dasar dari skenario tubrukan kapal yang dilakukan dengan AHP (Analitycal Hierarchy Process) berpotensi terjadi. Perhitungan frekuensi tubrukan kapal menggunakan software Expert Choice. Gambar 6. Hasil Pemilihan Metode berupa powered collision atau ramming collision dan drifting collision menggunakan model SAMSON dari Gambar 7 menunjukkan bahwa berdasarkan perTabel 1. Spesifikasi Pipelay VesselExpert dan DivingChoice, Support Vessel hitungan AHP dengan metode MARIN. Diving Support Vessel Pipelay Vessel pemindahan pipa yang dipilih adalah Reverse S-Lay = 85.34 m = 77 m Length Length dengan nilai= 0,5452 %) =sedangkan cut and lift 4. Hasil dan Pembahasan 24.38 m (54,5 20,4 m Breadth Breadth 5.5 m = 8 m 0,455 (45,5%). Draught Draught berada tipis= dibawahnya dengan nilai 30 ton DP 2 dynamic positioning system Tension Capacity = Meskipun hasil dari TOPSIS dan AHP dengan Expert Choice 4.1 Hasil Pemilihan Metode Pemindahan Pipa Class = GL / Indonesia / Flag memberikan hasil yang sama yakni reverse S-Lay sebagai dengan TOPSIS metode yang terpilih namun nilai yang diberikan berbeda. Skenario untuk pipeline menimbulkan potensi tubrukan kapal Pada TOPSIS ini terdapat atribut yang masing-masing decommissioning ini bisa dilihat dengan DSV. Sedangkan pipelay barge atributnya memiliki beberapa sub atribut. Penilaian Jurnal Teknik BKI Edisi 02 - Desember 2014

16


Gambar 8 dimana DSV akan memotong

tetap berada di dekat alur selama proses

pipa setiap 200 meter. Aktivitas DSV

pemotongan pipa, persiapan dan expose

selama

pipe.

proses

pemotongan

bisa

Untuk

menverifikasi

hasil

yang

dilakukan

dengan

AHP

didapatkan dari perhitungan TOPSIS,

Hierarchy

pemilihan metode pemindahan pipa juga

software Expert Pemindahan PipaChoice. dengan Expert Choice

(Analitycal

menggunakan

Process)


Gambar 6. Hasil Pemilihan Metode

Gambar 7 : Hasil Pemilihan Metode Pemindahan Pipa dengan Expert Choice

Gambar 7. Hasil Pemilihan Metode Pemindahan Pipa dengan Expert Choice Tabel Vesseldan danDiving Diving Support Vessel Tabel1.1Spesifikasi : SpesifikasiPipelay Pipelay Vessel Support Vessel Diving Support Vessel

Pipelay Vessel

Gambar Length 7 menunjukkan metode yangmterpilih namun nilai yang = 85.34bahwa m = 77 Length 24.38dengan m = 20,4berbeda. m Breadth Breadth diberikan berdasarkan perhitungan =AHP Draught

=

5.5

m

Class / Flag

= GL / Indonesia

Draught

=

8

m

Expert Choice, pipa DP 2 dynamic positioning system = 30 ton Tensionmetode Capacitypemindahan yang dipilih adalah Reverse S-Lay 4.2.

dengan nilai 0,5452 Skenario (54,5 %) sedangkan Pengembangan Pipeline Decommisioning untuk pipeline cutSkenario and lift berada tipis dibawahnya decommissioning

ini

bisa

dilihat

nilai pipa 0,455yang (45,5%). Metode dengan pemindahan terpilihMeskipun berdasarkan TOPSIS danGambar AHP adalah reverse S-lay. metode reverse dimana DSV akan memotong hasil dari 8TOPSIS danPada AHP dengan S-lay ini akan digunakan pipelay barge dan Diving Support pipa setiap 200 meter. Aktivitas DSV Expert memberikan hasil yang Vessel (DSV). DariChoice beberapa opsi kapal pipelay, pipelay proses bisaDSV barge yangselama dipilih untuk proses pemotongan reverse S-lay serta sama yakni reverse S-Lay sebagai yang digunakan memiliki spesifikasi seperti pada Tabel 1 :

4.2.

Pengembangan

Skenario

Pipeline Decommisioning Skenario untuk pipeline decommissioning ini bisa dilihat Gambar 8 dimana DSV akan memotong pipa setiap 200 menimbulkan potensi pipa tubrukan Metode pemindahan yang kapal terpilih meter. Aktivitas DSV selama proses pemotongan bisa medengan DSV. Sedangkan pipelay barge berdasarkan nimbulkan potensiTOPSIS tubrukan dan kapal AHP denganadalah DSV. Sedangkantetap pipelay bargedi berada dekat alur selama proses berada dekat alurdiselama proses reverse S-lay.tetap Pada metode reverse S-lay pemotongan pipa, persiapan dan expose pipe.

pemotongan pipa, persiapan expose ini akan digunakan pipelaydanbarge dan pipe. menggunakan metode Reverse S – Lay, waktu Dengan Diving Support Vessel (DSV). Dari

yang dibutuhkan untuk pemindahan pipa tiap segmen beberapa opsi total kapal pipelay, pipelay adalah 14 jam maka waktu pipeline decommissioning sepanjang 2900 m adalah 215 jam. Jika pekerjaan berhenti 1 beroperasi pada malam hari atau hanya 10 jam per hari maka dibutuhkan waktu 22 hari hingga seluruh pipa selesai dipindah. 4.3. Hasil Perhitungan Frekuensi Pada perhitungan frekuensi ini, kapal yang akan dianalisis adalah semua kapal yang menuju ataupun keluar Gresik dan Pelabuhan Tanjung Perak Surabaya yang melewati crossing II APBS. Sesuai data dari PT. Pelindo III, jumlah 1 kapal yang melewati APBS pada tahun 2013 adalah 24.093 unit kapal. Dengan estimasi kenaikan jumlah kapal tiap tahun sebesar 3% maka jumlah kapal yang melewati APBS pada tahun 2015 setiap jam adalah 3 unit kapal sehingga jumlah kapal (N) yang berpotensi menubruk DSV adalah 6 kapal dan untuk laybarge sebanyak 420 kapal. 4.3.1. Hasil Perhitungan Frekuensi Drifting Collision

Gambar : Skenario Pemotongan Pipa Gambar 7. 8 Skenario Pemotongan Pipa Dengan menggunakan metode Reverse S

decommissioning sepanjang 2900 m

– Lay, waktu yang dibutuhkan untuk

adalah 215 jam. Jika pekerjaan berhenti

pemindahan pipa tiap segmen adalah 14

beroperasi pada malam hari atau hanya

jam

10 jam per hari maka dibutuhkan waktu

maka

total

waktu

pipeline

Kecepatan drifting dari hasil perhitungan dengan persamaan 1 adalah sebesar 0,59 m/s atau 3,46 knot. Setelah diketahui kecepatan drifting kapal dan jarak drifting dari titik kapal ke objek yang akan ditubruk, maka waktu yang diperlukan untuk mencapai objek tersebut hingga kapal Jurnal Teknik BKI Edisi 02- Desember 2014 Jurnal Teknik BKI Edisi 03-Agustus 2016

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Jurnal Teknik BKI

PROPULSION PROPULSION Tabel 2 : Frekuensi Drifting Collision Berdasarkan Model SAMSON (outgoing) Tabel 2. Frekuensi Drifting Collision Berdasarkan Model SAMSON (outgoing)

Tabel 2. Frekuensi SAMSON Objek r Ψ Drifting ts Collision P EF Berdasarkan P AF NModel Break Freq(outgoing) Ndrifting Segmen 1 716.19 0.28 0.951 0.35 6 0.000029 5.791E-05 Objek rΨ ts P EF P AF N Break Freq Ndrifting Segmen 2 648.51 0.26 0.989 0.35 6 0.000029 6.022E-05 Segmen 1 716.19 0.28 0.951 0.35 6 0.000029 5.791E-05 Segmen 1 0.35 0.000029 6.090E-05 Segmen32 602.45 648.51 0.24 0.26 0.989 0.35 66 0.000029 6.022E-05 541.86 0.22 1 0.35 6 0.000029 6.090E-05 Segmen 4 Segmen 3 602.45 0.24 1 0.35 6 0.000029 6.090E-05 Segmen 5 483.17 0.19 1 0.35 6 0.000029 6.090E-05 1 0.35 6 0.000029 6.090E-05 Segmen 4 541.86 0.22 Segmen 0.35 0.000029 6.090E-05 Segmen65 423.78 483.17 0.17 0.19 11 0.35 66 0.000029 6.090E-05 Segmen 7 361.73 0.14 1 0.35 6 0.000029 6.090E-05 Segmen 6 423.78 0.17 1 0.35 6 0.000029 6.090E-05 Segmen 8 280.48 0.11 1 0.35 6 0.000029 6.090E-05 Segmen 7 361.73 0.14 1 0.35 6 0.000029 6.090E-05 Segmen 9 200.37 0.08 1 0.35 6 0.000029 6.090E-05 Segmen 8 280.48 0.11 1 0.35 6 0.000029 6.090E-05 Segmen 0.35 0.000029 6.090E-05 Segmen109 106.48 200.37 0.04 0.08 11 0.35 66 0.000029 6.090E-05 Segmen 0.35 0.000029 6.090E-05 Segmen11 10 142.87 106.48 0.06 0.04 11 0.35 66 0.000029 6.090E-05 Pipelay barge 718.29 0.29 0.95 0.35 30 0.000029 2.892E-04 Segmen 11 142.87 0.06 1 0.35 6 0.000029 6.090E-05

Pipelay barge 718.29 0.29 0.95

0.35 30

0.000029

2.892E-04

Tabel 3. Frekuensi Drifting Collision Berdasarkan Model SAMSON (incoming)

Tabel 3 : Frekuensi Drifting Collision Berdasarkan Model SAMSON (incoming)

Tabel 3. Frekuensi SAMSON Objek r Ψ Drifting ts Collision P EF Berdasarkan P AF NModel Break Freq (incoming) Ndrifting Segmen 8 262.39 0.10 1 0.35 6 0.000029 Objek rΨ ts P EF P AF N Break Freq 6.090E-05 Ndrifting Segmen 9 465.86 0.19 1 0.35 6 0.000029 6.090E-05 Segmen 8 262.39 0.10 1 0.35 6 0.000029 6.090E-05 Segmen 0.35 Segmen109 706.67 465.86 0.28 0.19 0.96 1 0.35 66 0.000029 0.000029 5.822E-05 6.090E-05 Segmen 11 923.95 0.37 0.85 0.35 6 0.000029 5.181E-05 Segmen 10 706.67 0.28 0.96 0.35 6 0.000029 5.822E-05 Segmen Segmen12 11 1135.70 923.95 0.45 0.37 0.77 0.85 0.35 0.35 66 0.000029 0.000029 4.679E-05 5.181E-05 Segmen 13 1340.59 0.53 0.70 0.35 6 0.000029 4.278E-05 Segmen 12 1135.70 0.45 0.77 0.35 6 0.000029 4.679E-05 Segmen 14 1548.00 0.61 0.65 0.35 6 0.000029 3.936E-05 Segmen 13 1340.59 0.53 0.70 0.35 6 0.000029 4.278E-05 Segmen Segmen15 14 1856.09 1548.00 0.74 0.61 0.58 0.65 0.35 0.35 66 0.000029 0.000029 3.519E-05 3.936E-05 Frekuensi Drifting Segmen Kumulatif 15 1856.09 0.74 Kapal 0.58dengan 0.35DSV6 0.000029 3.959E-04 3.519E-05 Frekuensi 4.049E-03 FrekuensiKumulatif KumulatifDrifting Drifting Kapal Kapaldengan denganPipelay DSV barge 3.959E-04 Frekuensi Kumulatif Drifting Kapal 4.445E-03 Frekuensi Kumulatif Drifting Kapal dengan Pipelay barge 4.049E-03

Frekuensi Kumulatif Drifting Kapal

Dengan menjumlahkan seluruh frekuensi

menubruk. Jika waktu untuk perbaikan mesin lebih lama tubrukan dengan DSV padafrekuensi seluruh Dengan kapal menjumlahkan seluruh dari ts, maka kapal tidak akan mampu menghindari DSV segmen, maka frekuensi kumulatifnya tubrukan kapal dengantertabrak. DSV pada seluruh atau laybarge sehingga kapal dapat Dengan adalah 0,001062. Frekuensi pipelay frekuensi kumulatifnya mengalikan peluangsegmen, enginemaka failure ini dengan kegagalan emergency anchor, kapalFrekuensi yang lewat dan adalah jumlah 0,001062. pipelay 2 breakdown frequency, maka frekuensi tubrukan kapal aki2 bat drifting dapat diketahui. Dengan menjumlahkan seluruh frekuensi tubrukan kapal dengan DSV pada seluruh segmen, maka frekuensi kumulatifnya adalah 0,001062. Frekuensi pipelay barge lebih besar karena durasi pipelay barge didekat alur lebih lama yakni 10 jam per hari, sehingga jumlah kapal (N) adalah 30 kapal untuk 10 jam per hari. Karena dari hasil estimasi durasi pipelay barge bekeraja untuk pemindahan pipa Jurnal Teknik BKI Edisi 02 - Desember 2014

18


4.445E-03

barge lebih besar karena durasi pipelay

ini adalah 140 jam, maka frekuensi kumulatiff drifting barge alur karena lebih lama yakni 10 barge didekat lebih besar durasi pipelay kapal dengan pipelay adalah 0,004049. Berdasarkan perjam per hari, sehingga jumlah kapal (N) barge didekat alur model lebih lama yakni 10Selama proses pipeline hitungan dengan SAMSON, adalah 30 kapal untuk 10 jam per hari. jam per hari, sehingga jumlah kapal (N) kapal dengan DSV decommissioning, frekuensi tubrukan dan pipelay barge adalah sebesar 0,00511. adalah 30 kapal untuk 10 jam per hari. 4.3.2. Hasil Perhitungan Frekuensi Powered Vessel atau Ramming Collision Dari hasil perhitungan untuk frekuensi tubrukan kapal berupa powered atau ramming collision pada sudut 10⁰, 20⁰ dan 30⁰ serta frekuensi kumulatifnya terangkum pada Tabel 4 dibawah ini. Berdasarkan hasil perhitungan frekeunsi ramming collision pada Tabel 4.76 diatas, frekuensi tubrukan terbesar terjadi


Tabel 4 : Frekuensi Kumulatif Ramming Collision untuk Semua Sudut

Objek Segmen 1 Segmen 2 Segmen 3 Segmen 4 Segmen 5 Segmen 6 Segmen 7 Segmen 8 Segmen 9 Segmen 10 Segmen 11 Segmen 12 Segmen 13 Segmen 14 Segmen 15 Pipelay barge Frekuensi Kumulatif (DSV) Frekuensi Kumulatif (Pipelay)

Frek Kumulatif

Ψ = 10⁰ N ramming N ramming (outgoing) (incoming) 3.35E-05 5.47E-05 3.62E-05 6.21E-05 3.82E-05 6.28E-05 4.10E-05 6.77E-05 4.40E-05 7.00E-05 4.73E-05 7.00E-05 5.08E-05 7.00E-05 5.60E-05 7.00E-05 6.15E-05 6.44E-05 6.88E-05 5.83E-05 7.61E-05 5.33E-05 7.61E-05 4.89E-05 6.86E-05 4.49E-05 6.10E-05 4.13E-05 5.34E-05 3.63E-05 2.15E-03 3.72E-03 1.69E-03 5.87E-03 7.55E-03

pada kapal yang mengalami perubahan arah 10⁰ dengan nilai frekuensi 0,00169 untuk kapal dengan DSV dan 0,0058 untuk kapal dengan pipelay barge. Hal ini diakibatkan nilai probabilitas perubahan arah ke sudut 10⁰ paling besar yakni 0,2. Frekuensi kumulatif tubrukan kapal dengan DSV dan pipelay barge selama proses pipeline decommissioning adalah sebesar 0,00755 untuk 10⁰, 0,00504 untuk 20⁰ dan 0,00274 untuk 30⁰ serta untuk semua sudut frekuensinya menjadi 0,0153.


6.


Daftar Pustaka

Artana, KB. (2009). Penilaian Risiko Pipa Gas Bawah Laut Ujung Pangkah-Gresik Dengan Standard DNV RP F107. Surabaya. Artana, KB ; Dinariyana, A.A.B ; Ariana, I.M ; Sambodho, Kriyo, S. (2013). Penilaian Risiko Pipa Gas Bawah Laut . Surabaya : Guna widya. Axon, S. (2015). Stamford Decommissioning Comparative Assessment. UK. Baltic Sea Region. (2011). Efficient, Safe and Sustainable Traffic at Sea. Finlandia. 5. Kesimpulan BP. (2005). North West Hutton Decommissioning Programme. US : BP Press. Hasil perhitungan frekuensi tubrukan kapal untuk powered Lotfi, F. H., Fallahnejad, R., & Navidi, N. (2011). Ranking effivessel atau ramming collision sebesar 0,0153 dan drifting cient units in DEA by using TOPSIS method. Applied Mathematical Sciences, 5(17), 805-815. collision sebesar 0,00511 menunjukkan bahwa selama Majalah Dermaga. (2013). “Alur Pelayaran Barat Surabaya proses pipeline decommissioning dengan metode reverse Emmy Pratiwi, Saat ini penulis sedang menempuh S1 masih di Institut Teknologi Sepuluh menghambat”. Surabaya. S-lay tersebut, frekuensi tubrukan kapal masih dapat MARIN. Contact Drift Model. [pdf]. (www.iala-aism.org/ Nopember, Teknik diterima karena nilainyaJurusan kurang dari Sistem 1. Hal Perkapalan. ini telah Penulis mengambil bidang Reliability, wiki/iwrap/images/6/65/Contact_drift.pdf, diakses Maintanibility Safety IIIdi bahwa Laboratorium Marine Reliability Safety sekaligus sesuai dengan tujuan dariandPelindo di APBS tanggal 5and Januari 2015). nantinya tidak terjadi kecelakaan pelayaran MARIN. Contact Ram Model. [pdf]. (www.iala-ism.org/ mengerjakan tugas akhir di bidang yang sama. [email protected]. wiki/iwrap/images/b/b7/Contact_ram.pdf‎, diakses setelah dilakukan revitalisasi. Selain itu, jika frekuensi 3 tanggal 5 Januari 2015). dari hasil perhitungan ini kurang dari satu maka proses Offshoreenergy.dk. (2013). A Danish Field Platforms and pipeline decommissioning tidak mengganggu keselamatan Pipelines Decommissioning Programmes. Denmark. pelayaran. Jurnal Teknik BKI Edisi 02- Desember 2014 Jurnal Teknik BKI Edisi 03-Agustus 2016

19

Jurnal Teknik BKI

PROPULSION PROPULSION Oil & Gas UK. (2013). Decommissioning of Pipelines in North Sea Region. London. PT. Pelindo III. (2014). “Press Release : Pengerukan Alur Pelayaran Barat Surabaya Dimulai Mei 2014”. PT. Pelindo III. (2014). “Revitalisasi APBS Tingkatkan Kapasitas Tanjung Perak Hingga 5 Juta TEUs”.

Objek Segmen 1 Segmen 2 Segmen 3 Segmen 4 Segmen 5 Segmen 6 Segmen 7 Segmen 8 Segmen 9 Segmen 10 Segmen 11 Segmen 12 Segmen 13 Segmen 14 Segmen 15 Pipelay barge Frekuensi Kumulatif (DSV) Frekuensi Kumulatif (Pipelay)

Frek Kumulatif



Ψ = 30⁰ N ramming N ramming (outgoing) (incoming) 1.45E-05 1.75E-05 1.49E-05 1.79E-05 1.52E-05 1.82E-05 1.56E-05 1.87E-05 1.60E-05 1.87E-05 1.64E-05 1.87E-05 1.68E-05 1.87E-05 1.74E-05 1.87E-05 1.80E-05 1.82E-05 1.87E-05 1.75E-05 1.84E-05 1.70E-05 1.83E-05 1.65E-05 1.87E-05 1.60E-05 1.80E-05 1.54E-05 1.72E-05 1.48E-05 1.02E-03 1.21E-03 5.17E-04 2.23E-03 12. Offshoreenergy.dk (2013). A Danish 2.74E-03 Field

Platforms

Decommissioning

and

Pipelines

Programmes.

Denmark.

Prof. Dr. Ketut Buda Artana, ST, MSc, Staf Pengajar Jurusan Teknik Sistem Perkapalan Fakultas Teknologi Kelautan ITS, [email protected]

Robert C. Byrd, PE, Donald J. Miller, dan Steven M. Wiese. (2014). Cost Estimating for Offshore Oil & Gas Facility Decommissioning. US.


Menteri

Energi

Dan


Pedoman

Teknis

Pembongkaran Instalasi Lepas Pantai Minyak Dan Gas Bumi. 15. Swiss

Association


Construction

of

Concrete

Cutting Enterprises

Technical Cutting

Manual

for

Specialists.



Emmy Pratiwi, Saat ini penulis sedang menempuh S1 di Institut Teknologi Sepuluh Nopember, Jurusan Teknik Sistem Perkapalan. Penulis mengambil bidang Reliability, Maintanibility and Safety di Laboratorium Marine Reliability and Safety sekaligus mengerjakan tugas akhir di bidang yang sama. [email protected] Emmy Pratiwi, Saat ini penulis sedang menempuh S1 di Institut Teknologi Sepuluh nomer 68 (2011). Alur Pelayaran Laut. 14. Peraturan

Menteri

Energi

Dan


Pedoman

Teknis

Pembongkaran Instalasi Lepas Pantai Minyak Dan Gas Bumi.

15. Swiss

12. Offshoreenergy.dk (2013). A Danish Field

Platforms

Decommissioning

and

Pipelines

Programmes.

Denmark.

Association


Technical

Construction

of

Concrete

Cutting Enterprises

Cutting

Manual

for

Specialists.


Ayudhia

Pangestu

Gusti,

menempuh



Nopember, Jurusan Teknik Sistem Perkapalan. Penulis mengambil bidang Reliability, Maintanibility and Safety di Laboratorium Marine Reliability and Safety sekaligus

Prof. Dr. Ketut Buda Artana, Staf Pengajar Jurusan 3 Teknik Sistem Perkapalan - Fakultas Teknologi Kelautan ITS. [email protected]

mengerjakan tugas akhir di bidang yang sama. [email protected].

Jurnal Teknik BKI Edisi 02 - Desember 2014 Ayudhia

20

Pangestu

Gusti,

Jurnal menempuhTeknik BKI Edisi 03-Agustus 2016


A.A. Bgs. Dinariyana Dwi Putranta, Staf Pengajar Jurusan Teknik Sistem Perkapalan - Fakultas Teknologi Kelautan ITS, kojex@its. ac.id , [email protected]

PENILAIAN RISIKO KEBAKARAN PROSES GAS LIQUEFACTION PADA UNIT FLNG Munir Muradi, Ketut Buda Artana, A.A.B Dinariyana D.P

Abstract Process of gas liquefaction units on Floating Liquefied Natural Gas (FLNG) is still very vulnerable to fire risks and other types of damage caused by gases released during operation. It is necessary for the proper analysis of fire risk analysis on the system. Methods of risk assessment Carried out According to the rules of the Application of Risk Assessment for the Marine and Offshore Oil and Gas Industries. Hazard identification is done by using Hazard Operability (HAZOP), frequency analysis with Fault Tree Analysis (FTA) and the value of the frequency of occurrence of the possible repercussions of the release of gases Reviews such as Jet Fire, Flash Fire, explosion of gas and gas dispersion using Tree analysis (ETA). Consequence Analysis with fire simulation software. Based on the analysis of the frequency and consequence, the level of risk represented by the F-N curve Refers to the standard UK offshore 1991. The results obtained from this study that the potential impact of the type of jet fire Consequences are in acceptable condition, the risk of a gas pipeline on the acceptable level. The Consequences of a very small possibility of a gas explosion at a frequency value <10-6 and the Consequences of the gas dispersion can not cause toxic effects in Humans due to the release of the gas is still under 50,000 ppm. Keywords : Risk Assessment, Jet Fire. Flash Fire, Gas Explosion, Gas Dispersion

1.

P

Pendahuluan

2.

otensi gas bumi yang dimiliki Indonesia berdasarkan status tahun 2008 mencapai 170 TSCF dan produksi per tahun mencapai 2,87 TSCF, dengan komposisi tersebut Indonesia memiliki reserve to production (R/P) mencapai 59 tahun [ESDM, MIGAS, 2007]. Namun lokasi jauh daratan dan dengan sistem pipanisasi tidak memungkinkan gas untuk dibawa kedarat dan aplikasi tersebut tidak kompetitif. Pemerintah indonesia saat ini tengah melakukan perencanaan untuk exploitasi gas tersebut dengan membangun sebuah Floating Liquefied. Natural Gas (FLNG). Dalam perencanaan fasiltas instalasi tersebut harus memperhatikan banyak hal penting, salah satunya adalah Instalasi gas liquefaction process. Untuk itu pengadaan sebuah instalasi yang dibangun dengan tujuan pengolahan gas bumi harus memenuhi syarat-syarat teknis dan keselamatan kerja yang sesuai dengan sifat-sifat khusus dari proses dan lokasi operasi dari fasilitas tersebut [PP No. 11 Tahun 1979]. Dari pengamatan terhadap adanya upaya pemenuhan syarat-syarat keselamatan tersebut, maka harus dilakukan analisa risiko yang tepat untuk keberlangsungan pengoperasian instalasi tersebut.

Jurnal Teknik BKI

PROPULSION

Metode

Metode yang digunakan adalah seperti yang terdapat di dalam Tabel 1.

3.

Hasil dan Diskusi

3.1.

Identifikasi Hazard dengan HAZOP

Dalam pelaksanaan identifikasi dilakukan pembagian subsistem atau biasa dikenal dengan pembagian node agar mempermudah untuk melakukan analisa terhadap sistem yang diindetifikasi. Dalam melakuan identifikasi umumnya sistem yang dianalisa akan dipecah menjadi beberapa bagian sub-sistem dan selanjutnya sebuah tim akan melakukan evaluasi dengan metode brain storming atau dibantu seperangkat checklist [Artana, et al. 2013]. Untuk hal yang sama seperti pada Tabel 3. Dilakukan terhadap semua node atau subsystem sehingga akan dihasilkan identifikasi terhadap bagian-bagian atau kompoen-kom-

21


Jurnal Teknik BKI


Identification HAZOP, dalam

Jurnal Teknik BKI

PROPULSION proses ini kata kunci (how, low, no,dll)

PROPULSION mengetahui deviasi proses berdasarkan parameter yang telah ditetapkan

Hazard

Frequency Analysis

Risk Evaluation

Frekuensi dari

Perkiraan

Risiko tersebut

gagalnya system

konsekuensi dengan

direpresentasikan

dengan FTA dan

simulasi pemodelan

kedalam f-N Curve

Frekuensi terjadinya

sesuai dengan

berdasarkan

incident dalah hal ini bentuk skenario Tabel 1 : Risk Assessment Method fireTabel risk dengan menggunakan 1. Risk Assessment Method

Event Tree RiskAnalysis Assessmentsoftware MethodALOHA (ETA).

Frequency Analysis Identification 3. HASIL DAN DISKUSI HAZOP, dalam

Frekuensi dari

proses ini kata kunci

gagalnya system

mengetahui deviasi

Frekuensi terjadinya

proses berdasarkan

incident dalah hal ini

3.1

Analysis

Identifikasi Hazard dengan (how, low, no,dll) dengan FTA dan HAZOP

Dalam pelaksanaan identifikasi dilakukan parameter yang risk dengan pembagian subsistem ataufire biasa dikenal telah ditetapkan Tree Analysis dengan pembagian Event node agar (ETA). mempermudah untuk melakukan analisa terhadap sistem yang diindetifikasi. 3. HASIL DAN DISKUSI

Consequence Analysis

Acceptance Criteria UK Offshore HSE, 1991

Risk Evaluation

Perkiraan Risiko tersebut Dalam melakuan identifikasi umumnya konsekuensi dengan direpresentasikan sistem yang dianalisa akan dipecah simulasi kedalam f-N Curve menjadipemodelan beberapa bagian sub-sistem dan sesuai dengan berdasarkan selanjutnya sebuah tim akan melakukan bentuk skenario Acceptance Criteria evaluasi dengan metode brain storming menggunakan UK Offshore HSE, atau dibantu seperangkat checklist. [Artana, al. 2013] softwareetALOHA 1991

Dalam Tabel 22.: Pembagian Nodemelakuan identifikasi umumnya Tabel sistem yang dianalisa akan dipecah 3.1 Identifikasi Hazard dengan menjadi beberapa bagian sub-sistem dan No. Node. Deskripsi HAZOP selanjutnya sebuah tim akan melakukan 1. Warm MCHE Merupakan proses pendinginan dry natural gas (FEED GAS) evaluasi dengan metode brain storming Dalam pelaksanaan identifikasi untuk dilakukan memudahkan dalam atau proses dibantupencairan. seperangkat checklist. pembagian subsistem atau biasa dikenal 2. WMR WMR Accumulator [Artana, merupakan system rangkaian multi et al. 2013] dengan pembagian node agar Accumulator componen refrigerant dalam hal ini pengkondisian gas mempermudah untuk melakukan analisa butane menjadi dua fasa yaitu liquid dan vapour. terhadap sistem yang diindetifikasi. 3. CMR Separator CMR Separator merupakan rangkaian sistem pencairan gas, 2. Pembagian Node dan ethane) yang telah dimanaTabel pendingin (nitrogen No. Cold MCHE Node. 4. 1. Warm MCHE 2.

digunakan kedalam Warm MCHE. Deskripsi dan subcooling pada dry Merupakan tahap proses pencairan Merupakan pendinginan dry natural gas o(FEED GAS) C dengan natural gas proses sehingga mencair pada suhu -162

WMR

untuk memudahkan dalam proses pencairan. menggunakan multi componen refrigerant. WMR Accumulator merupakan system rangkaian multi

Accumulator

componen refrigerant dalam hal ini pengkondisian gas butane menjadi dua fasa yaitu liquid dan vapour.

ponen yang dapat mengalami kegagalan fungsi pada Data Directory, 2010] dan process release frequency [Risk 3. CMR Separator CMR Separator merupakan rangkaian sistem pencairan gas, setiap node atau subsystem. Assessment Data Directory, 2010]. Sedangkan untuk dimana pendinginProbabilitas (nitrogenterjadinya dan ethane) yang Flash Fire, Gas telah Explosion ber3.2. Analisa Frekuensi data dari Chemical Engineering Transaction digunakan kedalamdasarkan Warm MCHE. Vol. 36, 2014, pada Riskpada Analysis 4. Cold MCHE Merupakan tahap proses pencairan danpublikasi subcooling dry of LNG Dengan input database nilai estimasi besarnya hole (hole Terminal [Vianello, et al., 2014]. Setelah data frekuensi kenatural gas sehingga mencair pada suhu -162oC dengan size) berdasarkan A Guide To Quantitative Risk Assessment gagalan diperoleh, maka selanjutnya adalah melakukan multi componenfrekuensi refrigerant. for Offshore Installation (DNV Technica)menggunakan dan kondisi gas perhitungan kegagalan untuk tiap node, dalam release rate dan ignition probability akibat kebocor- simulasi ini diskenariokan gagalnya sistem dapat dilihat an pipa mengacu pada International Association of Oil pada gambar berikut ini (Gambar 1). and Gas Producers Ignition Probability [Risk Assessment Jurnal Teknik BKI Edisi 02 - Desember 2014

22



Tabel 3 : HAZOP Node 1. Warm MCHE STUDY STUDY TITLE

=

FLNG

SHEET

=

1 of 4

TITLE DRAWIN

=

FLNG

SHEET

=

DRAWIN G NO

=

DWG. NO.204.006.001

NODE :

1

1 of 4 P&ID

G NO PART

=

DWG. NO.204.006.001

NODE :

1

RED CONSIDE

=

WARM MAIN CRYOGENIC HEAT EXCHANGER

RED

=

WARM MAIN CRYOGENIC HEAT EXCHANGER 1. BUTTERFLY VALVE

P&ID

PART CONSIDE

DESIGN DESIGN INTENT INTENT

=

SOURCE

=

SOURCE

DEVIAT

7. TEMP.TRANSMITTER

ACTIVITY :

1. GLOBE BUTTERFLY VALVE 2. VALVE

7. TEMP.TRANSMITTER 8.TEMP.INDICATOR

ACTIVITY :

3. 2. REDUCER GLOBE VALVE

9.PRESSURE SAFETY VALVE 8.TEMP.INDICATOR

3. FLOW REDUCER 4. TRANSMITTER

9.PRESSURE SAFETY VALVE

PRE-COOLING

4. FLOW FLOW INDICATOR TRANSMITTER 5.

10.PRESSURE TRANSMITTER

PRE-COOLING

6. 5. GATE FLOWVALVE INDICATOR

1. PRESSURE INDICATING 10.PRESSURE TRANSMITTER

6. GATE VALVE

1. PRESSURE INDICATING

RECOMENDATIO

NO

DEVIAT ION

SOURCE

POSSIBLE CAUSES

CONSEQUENCES

SAFEGUARDS

RECOMENDATIO NS

NO

ION

SOURCE

POSSIBLE CAUSES

CONSEQUENCES

SAFEGUARDS

NSthe 1. Seal on 1. Seal must on the flange be rigid flange must be

BV-01

rigid 2. Seal on the

BV-01 (20”) (20”) 1. 1.

if valve BV-01 and BV-02 if valve BV-01gas andline BV-02 blockage,

No

overpressure could blockage,which gas line

No flow

overpressure which could lead to gas release on

flow

BV-02 BV-02 (20”)

lead toflanged gas release on flanged

2. Seal must on the flange be overpressure on pipe, if pipe overpressure on pipe, if pipe rupture gas release leads to rupture gas release to Gas Dispersion and leads jet fire,

1.Flow transmitter/ 1.Flow

flash if any source fire Gas fire Dispersion and jetoffire, flash fire if any source of fire

(20”)

transmitter/ indicator indicator

insulated flange must be insulated 3. Provide 3. Provide cutoff automatic valves for line automatic cutoff valves for line leaks leaks 4. Insulate 4. Insulatethrough drainage drainage through under transfer under transfer lines lines

Gambar 1. Skenario kegagalan system / gas release Gambar 1. Skenario kegagalan system / gas release

Gambar 1 : Skenario kegagalan system / gas release


23

Jurnal Teknik BKI


Gambar 2 : FTA analysis for Frekuensi overpressure with hole diameter leak is 50mm, Node 1 Tabel 4 : Hasil perhitungan frekuensi terjadinya gas release untuk masing-masing rentang diameter kebocoran pada masing-masing node No. 1.

Node.

Scenario

Warm MCHE

2.

WMR Accumulator

3.

CMR Separator

4.

Cold MCHE

50 mm

100 mm

200 mm

1.912E-04

1.054E-04

1.782E-04

2.29E-05

5.38E-05

4.16E-05

1.63E-04

1.198E-04

Gas

5.78E-

release

04

Gas

3.97E-

release

04

Gas

3.70E-

release

04

Gas

5.22E-

release Scenario

Node.

No.

Gas release frequency

Gambar 2 menunjukkan perhitungan frekuensi terjadi1. Warm MCHE Gas nya overpressure untuk diameter lubang kebocoran 50release mm Immediate pada Node 1. Untuk hal yang sama2. dilakukan analisa Gas seWMR Ignition rupa terhadap beberapa asumsi lubang kebocoran pada Accumulator release 0.8 3. CMR setiap node. Dan hasilnya dapat dilihat pada Tabel 4. Gas Ignition Separator

04 Gas release frequency 50 mm

100 mm

200 mm

3.70E-

5.38E-05

2.06E-05 4.16E-05

gunakan analisa Event Tree Analysis (ETA) dilakukan terha5.78E- 1.912E-04 1.054E-04 dap04 semua node untuk beberapa asumsi ukuran diameter kebocoran pipa. Sehingga 3.97E- 1.782E-04 2.29E-05proses analisa perhitungannya Jet Fire dapat 04 dilihat pada gambar 3.

Open Atmosphere release 04 Dengan analisa

Flash Fire yang sama juga dilakukan perhitungan

0.01 4. Cold MCHE Gas 5.22E1.63E-04 5.14E-08 1.198E-04 Dan selanjutnya dari nilai tersebut0.0445 digunakan untuk meterhadap semua node untuk tiap ukuran diamaeter keborelease 04 Delayed nentukan frekuensi terjadinya incident berupa Jet Fire, coran, sehingga hasilnya dapat dilihat pada Tabel 5.

Flash Fire, gas explosionGas dan gas dispersion. Dengan mengRelease

0.2

Immediate

5.78E-04

Ignition 0.8

Congested Atmosphere

Ignition

No 0.0445 Ignition Gas 0.9555 Release

0

Open Atmosphere 0.01

Jet Fire

Explosion 2.06E-05

0.00E+00 Flash Fire

Gas

5.14E-08

Dispersion

Delayed

5.52E-04

0.2

5.78E-04 Congested Atmosphere Explosion Tabel 5. Hasil perhitungan Frekuensi Terjadinya Insident Akibat Gas Release 0

No

0.00E+00

Gas Gas Dispersion Explosion Dispersion 5.52E-04 5.52E-04 WMCHE0.95555.78E-04 2.06E-05 5.14E-08 0.00E+00 WMR 3.97E-04 terjadinya 1.41E-05 incident 3.53E-08 Gambar 3 : Proses perhitungan frekuensi untuk 0.00E+00 kebocoran 3.79E-04 50 mm pada 50 mm CMR 3.70E-04 1.32E-05 3.29E-08 0.00E+00 3.54E-04 Jurnal Teknik BKI Tabel 5. Hasil perhitungan Insident Akibat Gas Release CMCHE 5.22E-04 Frekuensi 1.86E-05Terjadinya 4.65E-08 0.00E+00 4.99E-04 Edisi 02 - Desember 2014 100 mm WMCHE 1.91E-04 7.65E-06 1.91E-08 0.00E+00 1.82E-04 Gas NodeIgnition Release

Hole

24


Hole

50 mm

Node

Gas Release

Jet Fire

Jet Fire

Flash Fire

Flash Fire

Gas

Gas

Gas

Explosion

Dispersion

WMCHE

5.78E-04

2.06E-05

5.14E-08

0.00E+00

5.52E-04

WMR

3.97E-04

1.41E-05

3.53E-08

0.00E+00

3.79E-04

CMR

3.70E-04

1.32E-05

3.29E-08

0.00E+00

3.54E-04

node 1

WMCHE

5.78E-04

2.06E-05

5.14E-08

0.00E+00

5.52E-04

WMR

3.97E-04

1.41E-05

3.53E-08

0.00E+00

3.79E-04

CMR

3.70E-04

1.32E-05

3.29E-08

0.00E+00

3.54E-04

50 mm

CMCHE

5.22E-04

Technical Journal of Classification and Independent Assurance 1.86E-05 4.65E-08 0.00E+00 4.99E-04

WMCHE

1.91E-04

7.65E-06

1.91E-08

0.00E+00

1.82E-04

WMR

1.78E-04

7.13E-06

1.78E-08

0.00E+00

1.69E-04

CMR

5.83E-05

2.15E-06

5.38E-09

0.00E+00

5.11E-05

CMCHE

1.63E-04

6.52E-06

1.63E-08

0.00E+00

1.55E-04

100 mm

Tabel 5 : Hasil perhitungan frekuensi terjadinya insident akibat gas release WMCHE 1.05E-04 Gas 4.22E-06 1.05E-09 1.05E-09 Gas 1.00E-04 Gas Hole WMR Node2.29E-05 Jet Fire Flash Fire 9.16E-07 2.29E-09 2.29E-10 2.18E-05 Release Explosion Dispersion 200 mm CMR WMCHE 4.16E-055.78E-04 1.66E-062.06E-05 4.16E-095.14E-08 4.16E-100.00E+00 3.95E-055.52E-04 CMCHE WMR1.20E-043.97E-04 4.79E-061.41E-05 1.20E-093.53E-08 1.20E-090.00E+00 1.14E-043.79E-04 50 mm CMR 3.70E-04 1.32E-05 3.29E-08 0.00E+00 3.54E-04 CMCHE

5.22E-04

1.86E-05

4.65E-08

0.00E+00

4.99E-04

WMCHE

1.91E-04

7.65E-06

1.91E-08

0.00E+00

1.82E-04

WMR

1.78E-04

7.13E-06

CMR

5.83E-05

3. 3 Analisa Kosekuensi 100 mm

Analisa kebakaran yang timbul karena CMCHE 1.63E-04 gagalnya sistem adalah disimulasikan WMCHE 1.05E-04 dengan menggunakan software ALOHA WMR 2.29E-05 200 mm Of Hazardous Area) (Areal Locations CMR 4.16E-05 yang memberikan output nilai besarnya CMCHE 1.20E-04 kebocoran dan radius sebaran api atau

gas yang terdispersi. Adapun skenario 1.78E-08 0.00E+00 1.69E-04 yang disimulasikan adalah Gas 2.15E-06 5.38E-09 0.00E+00 5.11E-05 Dispersion, Flash Fire, Gas Explosion 6.52E-06 1.63E-08 0.00E+00 1.55E-04 dan Jet Fire dengan sumber kebocoran 4.22E-06 1.05E-09 1.05E-09 1.00E-04 adalah pipa. Setelah dilakukan simulasi 9.16E-07 2.29E-09 2.29E-10 2.18E-05 dan diplotkan pada gambar FLNG unit 1.66E-06 4.16E-09 4.16E-10 3.95E-05 maka hasilnya dapat dilihat pada gambar 4.79E-06 1.20E-09 1.20E-09 1.14E-04 berikut ini:

3. 3 Analisa Kosekuensi Analisa kebakaran yang timbul karena gagalnya sistem adalah disimulasikan dengan menggunakan software ALOHA (Areal Locations Of Hazardous Area) yang memberikan output nilai besarnya kebocoran dan radius sebaran api atau

gas yang terdispersi. Adapun skenario yang disimulasikan adalah Gas Dispersion, Flash Fire, Gas Explosion dan Jet Fire dengan sumber kebocoran adalah pipa. Setelah dilakukan simulasi dan diplotkan pada gambar FLNG unit maka hasilnya dapat dilihat pada gambar berikut ini:

Gambar 4 : Hasil plot simulasi fireLiquefaction pada Liquefaction kebocoran Gambar 4. Hasil plot simulasi jet firejet pada processprocess dengan dengan kebocoran 50 mm 50 mm 3.3.

Analisa Kosekuensi

Dari

Tabel

5

dapat

disimpulkan

bahwa

untuk

Dari hasil plot simulasi pada sistem di yang kemungkinan bekerja pada module jetproses/ terjadinya fire untuk ukuran kebocoran kapal, dapat diketahui jumlah orang yang instalasi lain diatas FLNG. Analisa kebakaran yang timbul karena gagalnya sistem 50 mm dengan jumlah orang yang terdampak sebanyak terdampak berdasarkan jumlah orang software 5 orang dengan jarak 17-37 m, untuk kebocoran 100 mm adalah disimulasikan dengan menggunakan ALOHA (Areal Locations Of Hazardous Area) yang mem- dengan jumlah orang terdampak sebanyak 6 orang pada berikan output nilai besarnya kebocoran dan radius radius 21-45 m, serta untuk kebocoran 200 mm dengan sebaran api atau gas yang terdispersi. Adapun jumlah terdampaknya total 8 orang pada jarak 23-50 m. skenario yang disimulasikan adalah Gas Dispersion, Flash Fire, Gas Explosion dan Jet Fire dengan sumber kebocor- 3.4. Representasi Risiko an adalah pipa. Setelah simulasi dan Gambardilakukan 4. Hasil plot simulasi jetdiplotkan fire pada Liquefaction process dengan kebocoran 50 mm pada gambar FLNG unit maka hasilnya dapat dilihat pada Dari hasil analisa frekuensi dan konsekuensi untuk semua Gambar 4. ukuran kebocoran pada setiap node maka dihasilkan Dari hasil plot simulasi pada sistem di yang bekerja pada module proses/ seperti pada tabel berikut : kapal, pada dapatsistem diketahui jumlahdapat orang diketayang instalasimendapatkan lain diatas FLNG. Dari hasil plot simulasi di kapal, Setelah nilai frekuensi kejadian dan konterdampak berdasarkan jumlah orang hui jumlah orang yang terdampak berdasarkan jumlah sekuensi yang ditimbulkan karena terjadinya insident, orang yang bekerja pada module proses/ instalasi lain di- maka kedua nilai tersebut dianalisa direpresentasikan atas FLNG. dengan menggunakan F-N curve. Jurnal Teknik BKI Edisi 02- Desember 2014


25

Jurnal Teknik BKI

PROPULSION Tabel 6. Hasil simulasi Jet fire

PROPULSION No No 1

Tabel Jet Fire fire Tabel 6. 6 :Hasil Hasil simulasi simulasi Jet

Ukuran kebocoran Ukuran (mm) kebocoran 50 (mm)

Jumlah orang terdampak (N)

Mati Luka bakar Terpapar Jumlah orang terdampak (N) panas 1 Mati

1

50

1

2

100

1

2

100

1

3

200

1

3

200

Luka bakar

1

Terpapar panas

Radius (m) Radius (m) 17

1

24 17 37 24 21 37 29 21 45 29 23 45 32 23 50 32

3

1

3

2

3

2

3

3

4

3

4

50

Table Number of ofFatalities Fatalities(N) (N) Tabel7.7 Incident : Incidentfrequency frequency vs vs Number Hole Hole 50 mm 50 mm 100 mm 100 mm 200 mm 200 mm

Node

Table 7. Incident frequency vsNNumber of Fatalities (N) Jet Fire N Flash Fire Gas Explosion N Gas Dispersion

WMCHE Node WMR WMCHE CMR WMR CMCHE CMR WMCHE CMCHE WMR WMCHE CMR WMR CMCHE CMR WMCHE CMCHE WMR WMCHE CMR WMR CMCHE CMR

2.06E-05 Jet Fire 1.41E-05 2.06E-05 1.32E-05 1.41E-05 1.86E-05 1.32E-05 7.65E-06 1.86E-05 7.13E-06 7.65E-06 2.15E-06 7.13E-06 6.52E-06 2.15E-06 4.22E-06 6.52E-06 9.16E-07 4.22E-06 1.66E-06 9.16E-07 4.79E-06 1.66E-06

5 N 5 5 5 5 5 5 6 5 6 6 6 6 6 6 8 6 8 8 8 8 8 8

5.14E-08 Flash Fire 3.53E-08 5.14E-08 3.29E-08 3.53E-08 4.65E-08 3.29E-08 1.91E-08 4.65E-08 1.78E-08 1.91E-08 5.38E-09 1.78E-08 1.63E-08 5.38E-09 1.05E-09 1.63E-08 2.29E-09 1.05E-09 4.16E-09 2.29E-09 1.20E-09 4.16E-09

N -

CMCHE

4.79E-06

8

1.20E-09

-

Setelahtersebut mendapatkan nilai frekuensi Pada grafik-grafik diatas menunjukkan bahwa kejadian dan konsekuensi yang representasi risiko untuk kebocoran 50 mm berada pada Setelah mendapatkan nilai frekuensi karena insident,unkondisi risikoditimbulkan ALARP untuk semuaterjadinya node, sedangkan kejadian dan konsekuensi yang tuk kebocoran 100 mm dan 200 mm berada kondisi risiko ditimbulkan karena terjadinya insident, yang dapat diterima (acceptable) untuk semua node.

4.

Kesimpulan 1). Dari identifikasi Hazard yang telah dilakukan maka risiko fire hazard yang mungkin terjadi pada FLNG yaitu Jet Fire, Gas Explosion dan Gas Dispersion. 2). Dari hasil simulasi fire Hazard yang mungkin terjadi dengan software ALOHA diperoleh hasil sebagai berikut: Jurnal Teknik BKI Edisi 02 - Desember 2014

26


0.00E+00 Gas Explosion 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 1.05E-09 0.00E+00 2.29E-10 1.05E-09 4.16E-10 2.29E-10 1.20E-09 4.16E-10

N all all all all all all all

5.52E-04 Gas Dispersion 3.79E-04 5.52E-04 3.54E-04 3.79E-04 4.99E-04 3.54E-04 1.82E-04 4.99E-04 1.69E-04 1.82E-04 5.11E-05 1.69E-04 1.55E-04 5.11E-05 1.00E-04 1.55E-04 2.18E-05 1.00E-04 3.95E-05 2.18E-05 1.14E-04 3.95E-05

N N -

all 1.14E-04 maka 1.20E-09 kedua a). Hasilnilai analisatersebut untuk jetdianalisa fire diperoleh jarak direpresentasikan menggunakan sebaran dengan api dengan skenario kebocoran maka kedua nilai tersebut dianalisa F-N curve. 50 mm, 100 mm dan 200 mm dengan jarak direpresentasikan dengan menggunakan 17 m - 50 m dengan total fatalities 8 orang. F-N curve.

b). Untuk risiko Gas Explosion kemungkinan terjadinya sangat kecil yang terjadi pada hole 200 mm pada semua node, namun apabila terjadi dapat menghancurkan unit FLNG dengan jarak ledakan 644 m.

c). Sedangkan untuk Gas Dispersion dengan kebocoran maksimum 50mm, 100mm, 200mm hanya dapat merelease gas sebesar 17,000 ppm dan tidak membahayakan, karena yang termasuk kategori berbahaya ialah bila gas yang terilis dengan kadar gas >50,000 ppm.

elah mendapatkan nilai frekuensi adian dan konsekuensi yang mbulkan karena terjadinya insident,

maka kedua nilai tersebut dianalisa Technicaldirepresentasikan Journal of Classification anddengan Independentmenggunakan Assurance F-N curve.

50 mm 100 mm 200 mm

Gambar 5 : Representasi F-N curve jet fire event pada Node 1 Gambar 5. Representasi F-N curve jet fire event pada Node 1

50 mm 100 mm 200 mm

Gambar 6 : Representasi F-N curve jet fire event pada Node 2

Gambar 6. Representasi F-N curve jet fire event pada Node 2 Jurnal Teknik BKI Edisi 02- Desember 2014 Jurnal Teknik BKI Edisi 03-Agustus 2016

27

Gambar 6. Representasi F-N curve jet fire event pada Node 2 Jurnal Teknik BKI

PROPULSION

Gambar 6. Representasi F-N curve jet fire event pada Node 2

PROPULSION

50 mm 100 mm 100 mm

50 mm

200 mm 200 mm

Gambar 7. Representasi F-N curve jet fire event pada Node 3 Gambar 7 : Representasi F-N curve jet fire event pada Node 3 Gambar 7. Representasi F-N curve jet fire event pada Node 3

50 mm 50 mm

100 mm 100 mm

200 mm 200 mm

Gambar 8 : Representasi F-N curve jet fire event pada Node 4

Gambar 8. 8. Representasi F-N Gambar Representasi F-Ncurve curvejetjetfire fireevent eventpada pada Node Node 44 Jurnal Teknik BKI Edisi 02 - Desember 2014

28



5.

3). B erdasarkan dari plot hasil analisa frekuensi dan konsekuensi kedalam F-N curve, bentuk risiko yang mungkin terjadi yaitu jet fire untuk ukuran hole 50 mm berada pada kondisi ALARP. Dimana kondisi ini masih pada kondisi aman, namun bisa juga dilakukan mitigasi, salah satu langkah mitigasi yang dilakukan yaitu memperkecil peluang gagalnya system dengan menambah komponen pengaman pada sistem perpipaan. Sedangkan untuk diameter kebocoran 100 mm dan 200 mm berada pada kondisi Acceptable artinya risiko yang ditimbulkan dapat diterima.

Referensi

Artana, B, K., Dinariyana, B., Ariana, M, I., Sambodho, K, 2013, “Penilaian Resiko Pipa Bawah Laut” Institut Teknologi Sepuluh Nopember, Edisi Pertama, Penerbit Guna Widya, Surabaya. ESDM, MIGAS, 2007, “Rencana Penyediaan Gas Bumi Nasional” Departemen Energi dan Sumber Daya Mineral, Direktorat Jenderal Minyak dan Gas Bumi, Jakarta Peraturan Pemerintah No. 11 Tahun 1979” Keselamatan Kerja Pada Pemurnian dan Pengolahan Minyak dan Gas Bumi” Jakarta. Risk Assessment Data Directory, 2010 “International Association of Oil and Gas Producers” Ignition Probability. London, United Kingdom. Risk Assessment Data Directory, 2010 “International Association of Oil and Gas Producers” Process Release Frequency, London, United Kingdom. Vianello, Chiara., Maschio, Giuseppe, 2014 ”Risk Analysis of LNG Terminal” Chemical Engineering transaction, Vol. 36, ISBN 978-88-95608-27-3; ISSN 2283-9216, Italia.


Menteri

Energi

Dan


Pedoman

Teknis

Pembongkaran Instalasi Lepas Pantai Minyak Dan Gas Bumi. 15. Swiss 12. Offshoreenergy.dk (2013). A Danish Field

Platforms

and

Decommissioning

Pipelines

Programmes.

Denmark.

Association


Technical

Construction

of

Concrete

Cutting Enterprises Cutting

Manual

for

Specialists.


Prof. Dr. Ketut Buda Artana, ST, MSc,

StafPeraturan Pengajar Menteri Jurusan Perhubungan Teknik Sistem 13.

Perkapalan Fakultas Teknologi Kelautan ITS, [email protected]

Munir Muradi,ST, MT, adalah staf SBU Lepas Pantai, PT. Biro Munir Muradi, adalah staf SBU Prof. Dr. Klasifikasi Indonesia (Persero), denganLepas bidang keahlian propulsi danKetut Buda Artana, Staf Pengajar Pantai, PT. Biro Klasifikasi Indonesia Jurusan permesinan kapal serta Penilaian Risiko terhadap instalasi offshore.Teknik Sistem Perkapalan - Fakultas (Persero), dengan bidang keahlian propulsi Teknologi Kelautan ITS. [email protected] Penulis lulus Program sarjana (S1) pada tahun 2009 di Fakultas Teknik, dan permesinan kapal serta Penilaian Risiko Universitas instalasi Hasanuddin, MakassarPenulis dan lulus terhadap offshore. lu-program Magister (S2) pada tahun 2015 disarjana Fakultas Teknologi Kelautan, lus Program (S1) pada tahun 2009 Institut Teknologi Sepuluh A.A. Bgs. Dinariyana Dwi Putranta, Staf Nopember, Surabaya. Hasanuddin, [email protected]; [email protected] di Fakultas Teknik, Universitas Makassar Pengajar Jurusan Teknik Sistem Perkapalan dan lulus program Magister (S2) pada tahun 2015 di - Fakultas Teknologi Kelautan ITS, kojex@its. Fakultas Teknologi Kelautan, Institut Teknologi Sepuluh Jurnal Teknik BKI ac.id , [email protected] Nopember, Surabaya. [email protected]; munirradyet@ Edisi 02- Desember 2014 rocketmail.com Prof. Dr. Ketut Buda Artana, ST, MSc Jurnal Teknik BKI 29 Staf Pengajar Jurusan Teknik Sistem Perkapalan - Fakultas Teknologi Edisi 03-Agustus 2016 Kelautan ITS, [email protected] nomer 68 (2011). Alur Pelayaran Laut. 14. Peraturan

Menteri

Energi

Dan


Pedoman

Teknis

Pembongkaran Instalasi Lepas Pantai Minyak Dan Gas Bumi.

15. Swiss

Field

Platforms

Decommissioning

and

Association

Drilling and

12. Offshoreenergy.dk (2013). A Danish

(2007).

Pipelines

Construction

Programmes.

of

Concrete

Cutting Enterprises

Technical

Cutting

Manual

for

Specialists.


Denmark.


Ayudhia

Pangestu

Gusti,

menempuh

pendidikan S1 Jurusan Teknik Sistem Perkapalan, Fakultas Teknologi Kelautan, Institut

Teknologi Sepuluh Nopember (ITS). Penulis mengambil bidang Reliability, Availability,

Ayudhia

Pangestu

Gusti,

menempuh

pendidikan S1 Jurusan Teknik Sistem Perkapalan, Fakultas Teknologi Kelautan, Institut

Teknologi Sepuluh Nopember (ITS). Penulis mengambil bidang Reliability, Availability,

BKI 1st Guide in BWM Convention

Ratifikasi BWM Convention oleh Indonesia: November 2015

to be mandatory...

Kapal yang terkena aturan BWM Convention Pada dasarnya pemberlakuan peraturan BWM adalah untuk semua kapal yang didesain dengan sistem air ballast kecuali kapal yg menggunakan ballast tetap. Sedangkan persyaratan sertifikasi BWM adalah untuk kapal 400 GT atau lebih kecuali floating platform, FSU dan FPSO. Pemenuhan aturan BWM Convention Untuk memenuhi aturan BWM Convention, kapal harus memiliki BWMP (Ballast Water Management Plan) yang harus disetujui. Gambaran umum BWMP adalah sebagai berikut: � � �

�

Prosedur keselamatan kapal terkait dengan BWM. Deskripsi langkah - langkah dalam menerapkan persyaratan BWM. Rincian prosedur dalam membuang sedimen di laut maupun di darat. adanya designate officer yang bertanggungjawab terhadap BWMP.

Time frame implementasi BWM sebelum enter into force : Tanggal Kapasitas Air Ballast 2009 Pembangunan 3 3 < 2009 1.500 m < Kapasitas < 5.000 m D1 atau D2 3 < 2009 < 1.500 m3 atau < 5.000 m D1 atau D2 > 2009 < 5.000 m3 D2 2009 < tahun < 2012 > 5.000 m3 D1 atau D2 > 2012 Semua kapasitas

2012

2014

D1 atau D2 D2 D1 atau D2 D1 atau D2 D2 D2 D1 atau D2 D1 atau D2 D2 D2

2016 D2 D2 D2 D2 D2

Substantial Guidelines dalam BWM Convention: � Guidelines for ballast water management and development of ballast water management plans (G4) diadopsi melalui resolusi MEPC.127(53) � Guidelines for ballast water exchange (G6) diadopsi melalui resolusi MEPC.124(53) � Guidelines for approval of ballast water management systems (G8) diadopsi melalui resolusi MEPC.174(58) � Guidelines for ballast water exchange design and construction standards (G11) diadopsi melalui resolusi MEPC.149(55)

Link informasi terkait BWM Convention: � www.imo.org � www.globallast.imo.org

BKI - STATUTORY DIVISION Phone : +62 21 436 1899, 1901, 1903, 1904 Jl. Yos Sudarso No. 38 – 40 Tanjung Priok Jakarta 14320 e-mail : [email protected] website : www.bki.co.id

Biro Klasifikasi Indonesia

MOP MODEL TO DESCRIBE INDONESIAN SHIP ACCIDENTS

Wanginingastuti Mutmainnah and Masao Furusho

Abstract Research has shown that human factors are the main cause of ship accidents around the world. However, it does not seem true for Indonesia. The National Transportation Safety Committee (NTSC) of Indonesia published its maritime report in 2013, which showed that human factors caused 35% of the accidents while the others (65%) were attributed to technical factors. This means that the human factors were not the main contributing factor in Indonesian maritime accidents. The objectives of this study are to find the dominant factor, whether Man, Machine, Media or Management, to isolate the most common failure which caused or contributed to the accidents, to understand the characteristics of Indonesian ship accident, and finally to propose some recommendations to reduce the number of accidents. The analyses utilized 4M (Man, Machine, Media and Management) factors which has been developed into 3-Dimensional shaped model, called as MOP (4M Overturned Pyramid) Model. Keywords : Ship Accidents, MOP Model, Human Factors

1.

R

Introduction

ecently, there have been many studies on human error. Almost all the research says that human errors are the most common contributing factor to accidents. In maritime field, The Maritime Safety Authority of New Zealand said that Human Factors cause 49% of accidents, while 35% are caused by technical factors and 16% environmental factors (Hetherington et al, 2006). Baker and Seah (2004) presented some data relating to human error from a number of sources. Data from Australian Transportation Safety Bureau (ATSB) stated that human errors contribute 85% to accidents, and the Canadian Transportation Safety Board (TSB Canada) 84%. Baker and Seah also presented information from the United States Coast Guard database of the top-Level Accident Cited Causation which stated that 44% were caused by Human Factors, while Engineering failure was 40%, Weather 15% and Hazardous material 1%. In another paper, Card (2005) stated that Human Factors and ergonomic design contributed up to 81% of all maritime accidents involving death, based on data from Marine Accident Investigation Branch (MAIB) of the United Kingdom Department of the Environment. Kiriyama et al (2011) said in her paper that the percentage of marine casualties in Japan, caused by Hu-

Jurnal Teknik BKI

PROPULSION

man Factors was about 80% in total. From this data, we can conclude that Human Factors are a major cause of accidents. In Indonesia, there are two institutions that publish maritime accidents in Indonesia. One is the Marine Court Decision (MCD) and other is National Transportation Safety Committee (NTSC). These two institutions also count the number of causal factors. However, these institutions have different results. According to MCD, human error caused 57% of the 316 accidents that occurred from 2003 to 2012. However, NTSC said that human errors contributed to only 35%, and that 65% were caused by technical factors. Of the 52 accidents, NTSC pursued in the same period, 40% consisted of sinking, 27% fire/explosion and collision for each, and 6% capsizing (IMT, 2013a&b and TAC, 2009). This means that human errors were not the dominant contributing factor in the accidents. The report of accident investigations is published on NTSC’s website. Thus, it is possible to re-analyze the data utilizing a different method. By utilizing the 4M Factors developed by The United States National Transportation Safety Board (NTSB), the author categorize the causal factors of the accidents to see if they can be better explained through a 4M Factor Model analysis.

31


Jurnal Teknik BKI


Jurnal Teknik BKI

PROPULSION PROPULSION 2.

Literature Review

2.1.

Maritime Traffic System (MTS)

ant element to the Maritime Traffic System. Human designs, develops, builds, operates, manages, regulates, and interacts with all other elements of the system. Due to this interaction, this system can be obvious that ships can be analyzed as a combination of technology (the vessel, engine, equipment, instruments, etc) and a social system (the crew, their culture, norms, habits, custom, practices, etc.) (Grech et al, 2008). This STE system means that analyzing the maritime accidents can be said as system error rather than organizational or human error. Grech et al (2008) purposes that the STE System is consisted of seven domains. This model is also called as “The Septigon Model”. Table 1 is the domains and the definition, which originate from Rizzo and Save in 1999.

Before analyzing the maritime accidents, we have to know about the Maritime Traffic System (MTS). According to Kristiansen (2005), the MTS are actors, effects and deviations. It should be pointed out that the performance, or rather lack of performance from the actors, will be reflected in different types of deviations or non-conformities and result in some effects. While Rothblum (2000) said that MTS is a people system. In this system people interact with technology, the environment, and organizational factors. Since all the elements are connecting and affecting each other, the system is not as simple as dividing all the components to each elements. Mullai and Paulson (2011) say on their paper that the MTS is a very complex and large-scale socio-technical environment (STE) system comprising human and man-made entities that interact with each other and operate in a physical environment.

2.2.

As was stated before, STE is consisted of several domains, were the domain error, any accident will be happen. There are so many theories describing how the accidents can be happen or the phenomena of the accidents. Those theories can be described into three major phases, i.e. sequential, epidemiological, and systemic (Underwood and Waterson, 2013; Mullai and Paulsson, 2011). The Sequential Accident Model is the simplest types of accident models describing the accident as the result of time-ordered sequences of discrete events. The Epidemiological Accident Model describe the accident is like a disease, an outcome of any combination of factors, some manifest and some latent, that happen to exist together in space and time (Hol-

Grech et al (2008) cite the description of STE System from Furnham in 1997 as “a set of interrelated elements that functions as a unit for a specific purpose”. While the main elements of the Maritime Traffic System are objects of transport, means of transport, infrastructures, and facilities, which are linked by the information system and transport-related activities (Mullai and Paulson, 2011). Mullai and Paulson (2011) also says that human is a very import-

Term Society and culture Physical Environment Practice Technology Individual

Group

Organizational environment

Table 1 : The Septigon Model Term Definitions Table 1. The Septigon Model Term Definitions

Definition It refers to the sociopolitical and economic environment in which the organization operates. It refers to the surrounding environment, such as weather, visibility conditions, obstructions to vision, physical workspace environment (air quality, temperature, lighting conditions, noise, smoke, vibration, ship motion, etc.) It refers to such aspects as informal rules and custom. However, these are not related to written procedures or instructions. It refers to equipment, vehicles, tools, manuals, and signs, and also deals with human machine interaction issues. It refers to the human component, and incorporates such aspects as individual physical or sensory limitations, human physiology, psychological limitation, individual workload management and experience, skill, and knowledge. It refers to the relational and communication aspects, such as communication, interactions, team skills, crew/team resource management training, supervision, and regulatory activities. Group also deals with leadership, and teamwork. It refers to the company and management as well as the procedures, policies, norms, and formal rules.


32


Accident Models

S E

O

Individual

Group

Organizational environment

It refers to the human component, and incorporates such aspects as individual physical or sensory limitations, human physiology, psychological limitation, individual workload management and experience, skill, and knowledge. It refers to the relational and communication aspects, such as communication, Technical Journal of Classification and Independent interactions, team skills, crew/team resource management training, supervision, and regulatory activities. Group also deals with leadership, and teamwork. It refers to the company and management as well as the procedures, policies, norms, and formal rules.

Assurance

S E

O

G

P

I

T

Figure 1 : The Septigon Model: Society and culture, Physical Environment, Practice, Technology, Individual, Group, and Figure 1. The Septigon Model: Society and culture, Physical Environment, Practice, Technology, Organizational environmentenvironment Network (Revised, Grech et al, 2008) Individual, Group, and Organizational Network (Revised, Grech et al, 2008) 2.2. Accident Models

lnagel, 2002), or in other words, the contributing failures As was failures stated before, STE is consisted of several are ‘latent’ and ‘active’ (Underwood and Waterson, domains, were the domain error, any accident will 2013), as well asbebarrires. The Systemic Accident Model is 2.2. Accident Models happen. There are so many theories describing design to describe characteristic performance on the howthe the accidents can be happen or the phenomena As was stated before, STE is consisted of several of the accidents. Those theories can be described level of the system as a whole, rather than on the level domains, were the domain error, any accident will into be three major phases, i.e. sequential, happen. There are so many theories describing of specific cause-effect “mechanisms” (Hollnagel, 2002). It epidemiological, and can systemic (Underwood and how the accidents be happen or the phenomena Waterson, 2013; Mullai andtheories Paulsson, The describes the losses unexpected behavior of sysofasthethe accidents. Those can2011). be a described Sequential Accident Model phases, is the simplest types of into three major i.e. its sequential, tem caused by uncontrolled relationships between conaccident models describing the accident as theand epidemiological, and systemic (Underwood stituent parts (Underwood and Waterson, resultWaterson, of time-ordered sequences of discrete2011). events. 2013; Mullai and 2013). Paulsson, The

combination of factors, some manifest and some

Perrow (1984), describes a system using the dimenlatent, that happenwhich to exist together in space and time (Hollnagel, 2002), or in other words, the sions of coupling and manageability as shown on Figure contributing failures are ‘latent’ and ‘active’ 2. In the that figure, Maritime Transport is better explained by on level of specific cause-effect “mechanisms” failures (Underwood and Waterson, 2013), as well (Hollnagel, 2002). It describes the losses as the Epidemiological Model. This that the acas barrires. The Accident Systemic Accident Modelmeans is unexpected behavior of a system caused by design to describe the characteristic performance cidents in the MTS can be analyzed by their Latent condiuncontrolled relationships between its constituent onparts the (Underwood level of the and system as a whole, rather than Waterson, 2013). tions, and Active conditions. on the Barriers, level of specific cause-effect “mechanisms”

(Hollnagel, 2002). It describes losses as thea Even though Systemic Accidentthe Model provides unexpected behavior of of complex a system causedbetter by depth understanding accidents 3. Methods uncontrolled relationships its constituent than other models, it will between not be efficient to apply parts andsimple Waterson, 2013).(Underwood this(Underwood model for the accidents andFACTOR Waterson, MODEL 2013). Therefore, the model should 4M be utilized correctly based on the complexity of the accident or the system. In order to determine the system’s characteristic, propose a 4M Factors is oneHollnagel kind (2008) of methodology used to means accident. of characterizing system, modifying the by the United analyze This 4M Factors was found work of Perrow (1984), which describes a system States Transportation Safety and Board (NTSB). The using National the dimensions of coupling manageability as shown on Figure 2.Media, In that figure, factors are Man, Machine, and Management. Maritime Transport is better explained by These term is much easier toThis be means remembered for the inEpidemiological Accident Model. that the accidents in the the MTSMaritime can be analyzed by their teraction among Traffic Systems’ elements. Latent conditions, Barriers, and Active conditions.

The Sequential Epidemiological Accident describe the of Accident Model isModel the simplest types accident is like a disease, an the outcome of as anythe accident models describing accident Even though Systemic Accident Model provides a depth result of time-ordered sequences of discrete events. understanding of complex accidents better than otherthe The Epidemiological Accident Model describe accident is like a disease, outcome any models, it will not be efficient to apply thisanmodel forofthe combination of factors, some manifest and some simple accidents (Underwood and Waterson, 2013). latent, that happen to exist together in Therespace and time be (Hollnagel, or in based other words, fore, the model should utilized2002), correctly on thethe contributing failures are ‘latent’ and ‘active’ complexity of the accident or the system. In order2013), to deterfailures (Underwood and Waterson, as well as barrires. The Systemic (2008) Accident Model is mine the system’s characteristic, Hollnagel propose design to describe the characteristic performance a means of characterizing system, modifying the work of By relating the Maritime Traffic System effect-people to on the level of the system as a whole, rather than Tight

Low

High

Financial Markets

Chemical Plants

Dams Air traffic control

Space Missions

Coupling

Military Adventures

Tight

Power grids

Nuclear Power Plants

Railways Marine Transport

Military Early Warning

Assembly Lines Public Services

R&D Companies

Mining Manufacturing

Universities

Loose Low

Manageability

Post Offices High

Loose

Figure 2 : Accident Model Categorization, whether Sequential, Epidemiological, or Systemic (adapted from Underwood and Waterson, 2013) Jurnal Teknik BKI Edisi 02- Desember 2014


33

Figure 2. Accident Model Categorization, whether Sequential, Epidemiological, or Systemic (adapted from Underwood and Waterson, 2013) Jurnal Teknik BKI

3. METHODS PROPULSION

as follows: People means Man, Technology means Machine, Environment means Media and Organization means Management. Table 2 explain 4M FACTOR MODEL how the term of Maritime Traffic System from 4M Factors is one kind of methodology used to Rothblum changed to be 4M Factors. Canale et al analyze accident. This 4M Factors was found by Figure 2. Accident Model Categorization, whether Sequential, Epidemiological, or Systemic (adapted (2005) said(self) that these 4M Factors can beasutilized the United StatesofNational Transportation the 4M factors, the term each element become Safety as fol- individual centered properties, well asas relations from Underwood and Waterson, 2013) the firstthese step factors of risk (Furusho, assessment2000, which2013). is termed Boardmeans (NTSB). TheTechnology factors are means Man, Machine, lows: People Man, Machine, among However, the hazard identification. These factors provide a basic Media, and Management. These term is much Environment means Media and Organization means Man- IM designed for Man, the navigational domain as Model follows:isfor People means means (Fig3.easier METHODS framework analyzing systemsTechnology and determining to be remembered for the interaction among agement. Table 2 explain how the term of Maritime Traffic ure 3). All the relation whether are internal or Machine, Environment means elements Media intermediate and the relationships between composite that the Maritime Traffic Systems’ elements. By Organization means Management. Table 2 explain FACTOR MODEL System 4M from Rothblum changed to be 4M Factors. Canale concept are the interaction among the system to the safe work together to perform the mission. relating the Maritime Traffic System effect-people how the term of Maritime Traffic System from 4M Factors is one kind of methodology used to et al (2005) said that these 4M Factors can be utilized as in navigational activity. Since the Maritime Traffic System is to the 4M factors, the term of each element become Rothblum changed to be 4M Factors. Canale et al analyze accident. This 4M Factors was found by Table : MOP MOP Model Model definition (2005) said that these 4M Factors can be utilized as the United States National Transportation Table22.Safety definition the first stepMaritime of risk assessment which is termed Board (NTSB). The factors are Man, Machine, Traffic The Septigon These factors(Grech provide a basic Media, and Management. These term is much 4M Factors Definition Example hazard identification. System et al, framework for analyzing systems and2008) determining easier to be remembered for the interaction among (Rothblum, 2000) the relationships between elements that the Maritime Traffic Systems’ BySkills, Abilities, Man All elements that elements. Knowledge, People composite Individual, affectTraffic people doing Motivation,work Alertness, together to perform the mission. relating(M1) the Maritime System Memory, effect-people their tasks Experience, etc. Practice to the 4M factors, the term of each element become

PROPULSION

Machine (M2)

All elements, including technology, which help people to 4M Factors Definition complete their tasks that Man All elements Media All environments (M1) affect people doing (M3) that affect their tasksthe system and/or Machine All elements, people (M2) including technology, which Management All elements that help people to (M3) can control the complete their system and/or tasks people Media All environments (M3) that affect the system and/or people

Equipment, Information

display,2. Environmental Table MOP Modeldesign, definition Crew complements, Construction, Example etc.

Technology

Maritime Traffic System (Rothblum, 2000) People Environment

Technology

The Septigon (Grech et al, 2008) Individual, Society and Culture, Practice

Knowledge, Skills, Abilities, Climatic/weather condition Memory, Motivation, Alertness, (temperature, noise, sea state, Experience, etc. vibration, wave, tide, wind, Equipment, Information Technology Technology etc.), Economic condition, Physical display, Environmental design, Social politics, Culture, etc. environment Crew complements, Training scheme, Organization Group, Construction, etc. Communication, Work schedule, Supervising/ Organizational monitoring, Regulatory environment Climatic/weather condition Environment Society and activities, Procedures, Rules, (temperature, noise, sea state, Culture, Maintenance, etc. vibration, wave, tide, wind, etc.), Economic condition, Physical model can be develthe first step of risk assessment which is termed hazard wider than navigational activity, thisenvironment Social politics, Culture, etc. oped to a wider activity including the process Internal Concept: identification. These factors providethat a ibasic framework Management All elements Training scheme, Organization Group, of the prepa1 Human Relation ration sailing, the regulation, maintenance for analyzing(M3) systems andcan determining control the the relationships Communication, Workactivity2 before Human Interface Man system and/or schedule, Supervising/ Organizational d of the ships, and so on. 3 Media Information between composite elements that work together to pera 4 Self Control people monitoring, Regulatory environment form the mission. 1 activities, Procedures, Rules, Intermediate Concept: The author modified the Maritime Traffic System (Rotha Man-Machine Interface for Navigation Maintenance, etc. 4 iv 2 ii b Information Aids for Navigation I Management Machine blum, 2000), The Septigon (Grech et al, 2008) (Figure 2) Related to this 4M Factors, Prof. M. Furusho designed the

IM-Model which has an underlying concept based on the 3 c

b

i

Media

Man iii

d

a

1 iv

Management

4

I

2

Machine

3 b

c

Media iii

c

Maritime Environmental Protection

and IM modeld from Furusho (2013) (Figure 3) become simBridge Resource Management External Concept: Internal Concept: i STCW Human Relation ii1 SOLAS 2 MARPOL Human Interface iii 3 COLREG Media Information iv 4 Self Control Intermediate Concept: a Man-Machine Interface for Navigation ii b Information Aids for Navigation c Maritime Environmental Protection d Bridge Resource Management

External Concept: i STCW ii SOLAS iii MARPOL iv COLREG

Figure 3 : IM Model (revised Furusho, 2000, 2013) Jurnal Teknik BKI Edisi 02 - Desember 2014

34



pler. Table 2 is the MOP Model description of each factor which is adapted from Rothblum (2000), Grech et al (2008) and some modification purposed by the author. The simplification purposed by the author can be seen in Figure 4 as 3 Dimensional relationship. This model is drawn as 3 Dimensional relationship looking like 3 sided inverted pyramid, where each factor is connected and affecting each other. Man Factor should always be at the bottom. This because Man Factor is the intrinsic factor that the most affecting matter to other. Everybody has admitted that the core of the system is man, who design di equipment layout, decide the regulation, design the training scheme, design and construct the physical workspace, etc.

In that inverted pyramid, each 4M Factor becomes the corner which is connected to other factor by the edge. The edge line relation mean that each factor is affecting each other and of course affect to MTS. Since this inverted pyramid has 4 corners, there are 6 line relations that affect to MTS. or becomes Media: M3 ctor by the each factor ct to MTS. s, there are Machine: Management:

Man: M1

4.

er hip nt rs

Figure 4 : MOP Modelx Figure 4. MOP Model

Analysis and Discussion

The data which is analyzed in this research is only 30 cases from 2007 to 2012. It consists of 13 fire, 8 collision, 6 sinking, and 3 capsizing cases. From the analysis, we can 5 several 10 15 20 discuss items as follows :

0 a)

on nt es e ut ad on 0 b)

wave nnel area Tide Wind

te

M4

M2

Man Factor

a. The Most Dominant Factor and Common Failures The analysis results shows that the most dominant factor is Machine Factor with percentage of 35%, while Management Factors is 31%, Man Factor is 25%, and Media Factor is only 9%. It means that of all the investigated accident in 2007 until 2012, machine failure is 5 10 15 20 theFactor most dominant. This result is in accordance with Machine the analysis which was carried out by NTSC that technical factor is the dominant cause for accident with

percentage of 65% compared to Human Factors which is only 35%. Figure 5 is the detail failure classified to each factor. There are 7 types of causative factors in Machine Factor with total number of failure is 51. However, no one failure caused collision cases. All the failure was happened in fire, sinking, and capsizing cases (see Figure 5b). These causative factors are dominated by fire cases, with total number is 35 of 51 failures, since the dominant cases which were investigated by NTSC are fire. It makes sense that in all factor, fire is the dominant cases. However, the most common failure causing to fire accident is in this Machine Factor which is equipment failure. The total equipment failure of fire cases is 11 (see Figure 5b). Equipment failure is not only dominating fire cases, but also all accidents. From 30 cases of accidents, there were 144 failures where equipment failure is one of the most common failure with total number of failure is 19. The most common failure in this equipment failure is exceeding passenger, cargoes or seafarer which were happen to 1 cases of fire, 4 cases of sinking, and 2 cases of capsizing. In case of collision, there were no machine failure causing the accident. The collision is caused by Management Factor, with number of failure is 14, Man 11 failures, and media 5 failures. However, the most common causing failure to this collision cases is slipshod workmanship with total number of failure is 9. This causative factor is also one of the most common failure for all accident, the same as equipment failure, with number of failure is 19. In this slipshod workmanship, the most common failure is captain’s decision was wrong which was happen to 5 cases of collision and 2 cases of sinking. If we see each common failure, the cause is not only from one factor. For example, the exceeding passenger cargoes or seafarer can be caused by other factor, whether Man, Media or Management Factors, as well as the captain’ decision was wrong. In other words, simply categorizing the causative factor to each factor is not enough because those causative factor is also caused or affected by other factors. The interaction of 2 M factors will be discussed in the next part. Jurnal Teknik BKI Edisi 02- Desember 2014

0

5 c)

Media Factor

10

15

20


35

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PROPULSION

Man: M1

Figure 4. MOP Model

PROPULSION Incapability of seafarer Slipshod workmanship Lack of utilizing equipment Irresponsible crews or passengers 0

5 a)

10

15

20

10

15

20

Man Factor

Unsuitable construction Improper utilization equipment Flammable material existances Equipment failure Insufficient layout Equipment Overload Damaged ship construction 0 b)

5 Machine Factor

High and strength wave Narrow channel Shallow water area Low Tide Wind 0

5 c)

10

15

20

Media Factor

Unavailability of load line certificate Unavailability of stability booklet on board Poor management of monitoring and supervising… Lack of some navigation and safety equipments Poor application of Safety Management System (SMS) Poor communication Poor management of berthing schedule Poor cargo management Poor management of Personnel on board Lack of tugboat amount Vessel dysfunction Poor management of maintenance Fire/Explosion

Collision

Sinking

Capsizing 0

5

10

15

20

Figure 5 : Causative Factors for All Ship Accidents in Indonesia (2007-2012) (Unit: Number of Failures) b. The Characteristics of The Indonesian Ship Accidents As was known, failures happen were caused by not only one factor but also several factors play some roles. For example, the failure belonging to Man Factor can be affected by Machine, Media, or Management Factors. All the 4 M Factors are relating each other. Table 3 shows the relation matrix how the causative factors, which have been classified, are affected by other M factors. Since the failure is affected by other factors, it seems that the relation between all factors is described. For Jurnal Teknik BKI Edisi 02 - Desember 2014

36


example, the first causative factors from Man Factors, that is Irresponsible crews or passengers. This item is classified as Man Factor since the crew or passenger did something that irresponsible. However, that irresponsible is affected by the Management Factors. One of the irresponsible crews which happened was some crew members were not on board when cargo loading was being done. This fault would not be happened if the monitoring was well done. The monitoring is belongs to Management Factors.

Technical Journal of Classification and Independent Assurance crew members were not on board when cargo loading was being done. This fault would not be

happened if the monitoring was well done. The monitoring is belongs to Management Factors.

Table 3 : 4M Factors Relation Matrix of Causative Factors for All Ship Accidents in Indonesia Table 3. 4M Factors Relation Matrix of Causative Factors for All Ship Accidents in Indonesia 1 2 3 4

4M Fact Man (M1)

No.

4 5 6

Machine (M2)

3

2 3 4 5

Irresponsible crews or passengers (6)

o

Lack of utilizing equipment (5)

o

Slipshod workmanship (19)

o

Incapability of seafarer (6)

o

o

o

o

Equipment failure (19)

o o

Improper utilization equipment (11) Total of affected causative factors (n) Affecting Ratio (n/the number of causative factors = n/7) Wind (2)

o o

5 0.71

7 1.00

o 1 0.14 o

Low Tide (2)

o

Silting area (1)

o

Narrow channel 3)

o

High and strength wave (5)

3 0.43

o 0 0.00 o

Poor management of Personnel on board (11)

o

Management (M4)

o

o

o

4

9

4 1.00 o

o

Vessel dysfunction (1)

8

o

o

Lack of tugboat amount (1)

7

o o

Insufficient layout (7)

3

6

o

Equipment Overload (2)

Flammable material existences (3)

M4 o

o

1 0.25

2

5

M3

1 0.25 o

Total of affected causative factors (n) Affecting Ratio (n/the number of causative factors = n/5) Poor management of maintenance (1)

1

M2

4 1.00 o

Unsuitable construction (2)

Media (M3)

7

1

M1

Total of affected causative factors (n) Affecting Ratio (n/the number of causative factors = n/4) Damaged ship construction (7)

1 2

Causative Factors

0 0.00 o

5 1.00

o

o o

Poor cargo management (6)

o

Poor management of berthing schedule (1)

o

Poor communication (5)

o

Poor application of Safety Management System (SMS) (5)

o

Lack of some navigation and safety equipment (2)

0 0.00 o o o

o

o o

o

o o

o

o

10

Poor management of monitoring and supervising from company/port (8)

o

o

11

Unavailability of stability booklet on board (2)

o

o

12

Unavailability of load line certificate (1)

o

o

Total of affected causative factors (n) Affecting Ratio (n/the number of causative factors = n/12)

*Note: ‘o’ means affectedororrelated related to to the *Note: ‘o’ means affected thefactor factor

As can be seen from MOP Model (Figure 4), all the factor is related each other which is shown by the edge of the volume. In the case of Indonesian ship accidents, those relationship can be shown by Table 4, which is another version of Table 3. The number inside the bracket are the number of failure happened in Indonesian ship accidents. Let we see the causative factors in Machine Factors, which is damaged construction. This failure is also

10 0.83

4 0.33

1 0.08

12 1.00

caused by Man, and Management Factors. One example is leakage of high pressure fuel pipe happened in 2 accidents in fire case. This failure is belong to machine failure. However, the failure can be caused by the poor application of maintenance. The maintenance itself is belong to Management Factor while the one who do maintenance is belong to Man Factor. This relation can be illustrated into Man-Machine line (M12) which means the seafarer did not take care the pipe, Man-Management line (M14) which means the Jurnal Teknik BKI Edisi 02- Desember 2014


37

Jurnal Teknik BKI

PROPULSION PROPULSION Table 4 : Line Relation Matrix of Causative Factors for All Ship Accidents in Indonesia Table 4. Line Relation Matrix of Causative Factors for All Ship Accidents in Indonesia

2 3 4

4M Fact

Causative Factors

M12 o

Incapability of seafarer (6)

o

Equipment Overload (2)

o

Insufficient layout (7)

o

Machine (M2)

2

6

Wind (2)

4 5 1 2 3 4 5 6 7 8 9 10 11 12

Management (M4)

3

Media (M3)

Unsuitable construction (2)

2

o

o

o o

o o o

o

Improper utilization equipment (11)

1

M34

o

Equipment failure (19) Flammable material existences (3)

7

M24

o o

5

M23

o

Slipshod workmanship (19) Damaged ship construction (7)

4

M14 o

Lack of utilizing equipment (5)

1 3

M13

Irresponsible crews or passengers (6)

Man (M1)

No . 1

o o

Low Tide (2) Silting area (1) Narrow channel 3) High and strength wave (5) Poor management of maintenance (1) Vessel dysfunction (1) Lack of tugboat amount (1) Poor management of Personnel on board (11) Poor cargo management (6) Poor management of berthing schedule (1) Poor communication (5) Poor application of Safety Management System (SMS) (5) Lack of some navigation and safety equipment (2) Poor management of monitoring and supervising from company/port (8) Unavailability of stability booklet on board (2) Unavailability of load line certificate (1)

Total of affected causative factors (n) Affecting Ratio (n/the number of causative factors= n/28)

o

o o

o o

o o o

o o

o

o

o

o o o o o 10 0.36

2 0.07

14 0.50

1 0.04

8 0.29

2 0.07

*Note:‘o’‘o’ meansaffected affected or thethe factor *Note: means orrelated relatedtoto factor andrun 4 is the mademaintenance due to the 4Mwell, Factor model seafarerTable did 3not and Main Figure 4 All the factors are related and affecting chine- Management maineach other. Inline the(M24) case which of themeans most the common tenancefailures, plan was not really effective to the pipe so that both of them are affected by Management Factor which is in latent condition. Table 3 shows the pipe was failure. that Man and Management Factors affect most of the causative factors, then Machine Factor is As was moderate stated in and the Media previous part,is the Factor not most reallycommon affects. failure among all accidents are slipshod The relation between 2 M Factor is workmanship provided by and equipment failure. Those factor are also affected by other factor that is Management Factor (see Table 3). As in captain’s decision was not appropriate, it can be caused by lack of the communication among captain, other seafarers, etc. this communication is belong to Management Factor. As in equipment failure, the exceeding passengers, cargoes, and seafarers is also can be caused by Management Factor, such as lack of Jurnal Teknik BKI Edisi 02 - Desember 2014

38


Tablesupervising 4. From this table we can see company. that the or monitoring by the relational factor which is affected to the accidents Table 3 and is made due to the Factor model in in Indonesia are 4Man-Management Line,4MManFigure 4 All the factors are related and affecting each Machine Line, and Machine-Management Line. The other. relationInlines can be drawn to the 4M Factor the case of the most common failures, both model in Figure 6. of as them are affected by Management Factor which is in latent condition. Table 3 shows that Man and Management Factors affect most of the causative factors, then Machine Factor is moderate and Media Factor is not really affects. The relation between 2 M Factor is provided by Table 4. From this table we can see that the relational factor which is affected to the accidents in Indonesia are Man-Management Line, Man-Machine Line, and Machine-Management Line. The relation lines can be drawn to the 4M Factor model as in Figure 6.

the first effort to reduce the accidents. By fixing Table 4. From this table we can see that the the Management Factor, some of the causative relational factor which is affected to the accidents factors in and Machine Factors should be able in Indonesia are Man-Management Line, ManTechnical Journal of Man Classification and Independent Assurance to reduce as well. The next step is fixing the rest of Machine Line, and Machine-Management Line. causative factors. Even though the failures cannot The relation lines can be drawn to the 4M Factor be eliminated, at least it can be reduced by some model as in Figure 6. efforts. Media: M3 M23=1 of 28

Machine: M2

M24=8 28

M12=10 of 28

M34=2 28

of

Management: M4

of M14=14 of 28 M13=2 28

of

Man: M1 Figure 6 :Figure Line Relation to the Indonesian 6. Lineillustration Relation illustration to theShip Accident Indonesian Ship Accident Form that result, the characteristic of Indonesian acciForm that result, the characteristic of Indonesian dent can be obtained. The Man-Management Line is accident can be obtained. The Man-Management the most influencing relation to the accidents, where Line is the most influencing relation to the the Man-Machine and Machine-Management Lines accidents, where the Man-Machine and Machinealso influence the accident than thethe Man-ManManagement Lines alsolower influence accident agement Factor. lower than the Man-Management Factor.

The inverted pyramid is unstable, not like the

The invertedThis pyramid is unstable, not the pyramid. pyramid. geometrical canlikerepresent the This geometrical can represent the Maritime Maritime Traffic System where the errors Traffic caused System where the errors caused Man Factor because cannot by Man Factor cannot be byeliminated be eliminated because human has tendency to make human has tendency to make errors but it can be errors but To it can be reduced. To reduce the errors, the reduced. reduce the errors, the system should be system should be balance by making theedges corkept balance by kept making all the cornersalland ners andpyramid, edges of the or allFactors the 4M and Factors of the or pyramid, all the 4M the relation betweenbetween two factors, has the has samethe power. and the relation two factors, same power.

3. Recommendations The previous part obtains that the interaction c. Recommendations between Man-Management, and The previous part obtains that the Man-Machine, interaction between Man-Management, Man-Machine, and Machine-Management Lines are the influence factor to the accidents in Indonesia. Since the Management Factor is latent failure, it has to be considered that the failure in latent condition can be hidden for long time in the system until there is a trigger from barriers into active failures, then the accident can be happened. It should be pointed out that paying more attention to the causative factor which is related to Management Factor should be the first effort to reduce the accidents. By fixing the Management Factor, some of the causative factors in Man and Machine Factors should be able to reduce as well. The next step is fixing the rest of causative factors. Even though the failures cannot be eliminated, at least it can be reduced by some efforts.

The efforts that can be done to reduce the causative factors in management thecausative available The efforts that can besuch doneas:toreviewing reduce the regulations, increase the quality of training so that the factors in management such as: reviewing the communication can be better, increasethe the supervising available regulations, increase quality of or monitoring from company, and can etc. the study training so that thethe communication be better, about thisthe recommendation be continued in my increase supervising orwillmonitoring from the Doctoral research company, and activity. etc. the study about this

recommendation will be continued in my Doctoral activity. 5. research Conclusion 5.the CONCLUSION From result of the analysis and the discussion, the conclusions obtained are:

From the result of the analysis and the discussion, conclusions are: factor a. the Machine Factor isobtained the dominant By simply categorizing the causative factors into 4M

1. Machine Factor is the dominant factor Factors, Machine Factor was seen as the dominant facBy simply categorizing the causative factors into tor in Indonesian ship accidents. This means that the 4M Factors, Machine Factor was seen as the direct cause of most accidents is a failure of a Machine dominant factor in Indonesian ship accidents. This Factor failure. However, these direct causes are also afmeans that the direct cause of most accidents is a fected by other factors. failure of a Machine Factor failure. However, these direct causes are also affected by other factors. b. Slipshod workmanship and equipment are the 2. Slipshod workmanship andfailures equipment most common failures failures are the most common failures Of the out with a Of the causative causativefactors, factors,two twofactors factorsstand stand out with large number of active failures, 19 each, slipshod worka large number of active failures, 19 each, slipshod manship and equipment failures. The affecting workmanship and equipment failures.factors The that can lead to these kinds of failures are associated affecting factors that can lead to these kinds of with Management Factor. Since Management Facfailures are associated with the Management Factor. tor is a latent condition, fixing the causative factors in Since the Management Factor is a latent condition, Management Factor will be very tant. fixing the causative factors in impor Management Factor will be very important. c. Interaction between Man and Management, Man and Machine, and Machine and Management Lines are Vulnerable to Failure From Table 4, we can see that 3 lines of interaction are the influencing factors of Indonesian accidents, since the causative factors are also affected by these other factors. These are the barriers that lead to the active failures that happen in Indonesian ship accidents. The prevention action for reducing the number of accidents can be found in the latent failures, barriers, and active failures. To prevent latent failures, reducing the number of causative factors in Management Factor is needed. Fixing the barriers is also important since barriers can lead to active failures, we need to balance the power of each corner and edge so that they have the same power. The most urgent barrier to be fixed are Jurnal Teknik BKI Edisi 02- Desember 2014 Jurnal Teknik BKI Edisi 03-Agustus 2016

39

Jurnal Teknik BKI

PROPULSION PROPULSION the causative factors that are influenced through the Man-Management, Man-Machine, and Machine-Management Lines. A concrete solution for reducing the number of accidents will be the target of future research. A Comparison study of the other countries’ accidents would also be of interest to see if any inherent tendencies exist.

Acknowledgement My great thank is delivered to Mr. Aleik Nur-wahyudy, one of Investigator in Indonesian National Transportation Safety Committee, who supported me by explaining several condition of Indonesian MTS.

Reference Baker, C. C. and Seah, A. K. (2004). Maritime Accidents and Human Performance: the Statistical Trail. MARTECH 2004. pp. 225-239. Singapore. Card, J. C. et al (2005). Human Factors in Classification and Certification, 2005 SNAME Marine Technology Conference & Expo. pp. 127-137. United States. Canale, S., Distefano N., Leonardi, S. (2005). A Risk Assessment Procedure for the Safety Management of Airport Infrastructures. III Convegro Internazionale SIIV (People, Land, Environment and Transport Infrastructures). Bari, Italy. Furusho, M. (2000). IM Model for Ship Safety, proceedings of inaugural general assembly. Turkey. pp. 26-31. Furusho, M. (2013). Disaster of Italian Passenger Ship Costa Concordia – a Nightmare 100 Years After the Titan-

Wanginingastuti Mutmainnah, is an employee of PT BKI from 2012 before continuing her higher degree. Now, she is a First year of Doctoral Course student at Graduate School of Maritime Sciences, Kobe University, Japan and expected to be graduated in September 2017. She was graduated from the same university for her Master Degree in September 2014. For the Undergraduate Teknik BKI Faculty of Ocean Engineering, InstiDegree, Jurnal she got from Edisi 02 - Desember 2014 tute Technology of Sepuluh Nopember, Surabaya-IndoneSurabaya-Indonesia

Wanginingastuti Mutmainnah is an employee of PT BKI from 2012 before continuing her higher degree. Now, she is a First year of Doctoral Course student at Graduate School of Maritime Sciences, Kobe University, Japan and expected to be graduated in September 2017. She was graduated from the same university for her Master Degree in September 2014. For the Undergraduate Degree, she got from Faculty of Ocean Engineering, Institute Technology of Sepuluh Nopember,

40

in

September 2011. Her research interest includes ergonomics, risk and safety management, and accident analysis.

Masao Furusho is a professor at Graduate School of Maritime Sciences, Kobe University, Japan. His specialties are Seamanship, Safety and risk management, Ergonomics, Risk perception. The research interests are strongly related to 4 factors such as Man, Machine, Media, and Management.


Wanginingastuti Mutmainnah is an employee of PT BKI from 2012 before continuing her higher degree. Now, she is a First year of Doctoral Course student at Graduate School of Maritime Sciences, Kobe University, Japan and expected to be graduated in September 2017. She was graduated from the same university for her Master Degree in September 2014. For the Undergraduate Degree, she got from Faculty of Ocean Engineering, Institute Technology of Sepuluh Nopember,

ic-, The Mariners’s Digest. Vol 28. pp. 31-35 (Magazine). Grech, M. R., Horberry, T. J., and Koester, T. (2008). Human Factors in the Maritime Domain. CRC Press. France. Hetherington, C., Flin, R. and Mearns, K. (2006). Safety in Shipping: The Human Element. Journal of Safety Research. 37. pp. 401-411. Hollnagel, E. (2002). Understanding accidents-from root causes to performance variability. IEEE 7 Human Factors Meeting. Scottsdale Arizona. Hollnagel, E. (2008). The Changing Nature of Risks. Ergonomics Ausralia Journal. 22. pp. 33-46. Indonesian Ministry of Transportation (IMT) (2013a). Transportation Statistics 2012- Book I. Indonesia. Indonesian Ministry of Transportation (IMT) (2013b). Transportation Statistics 2012- Book II. Indonesia. Kiriyama, S., Nishimura, S. and Ishida, K. (2011). Influence of Human Factor on Marine Casualties. Proceeding of Asia Navigation Conference 2011. pp. 397-404. Wuhan, China. Kristiansen, S. (2005). Maritime Transportation. Safety Management and Risk Analysis, Elsevier Butterworth-Heinemann, Oxford. Mullai, A. and Palusson, U. (2011). A Grounded Theory Model for Analysis of Marine Accidents, Accident Analysis and Prevention. 43. pp.1590-1603. PT. Trans Asia Consultants (TAC) (2009). The Study on Trend Analyses of Sea Accidents in 2003-2008. Jakarta, Indonesia. Rothblum, A. M. (2000). Human Error and Marine Safety, National Safety Council Congress and Expo. Orlando, FL. Underwood, P. and Waterson, P. (2013). Accident Analysis Models and Methods: Guidance for Safety Professionals. Loughborough University. United Kingdom.

sia in September 2011. Her research interest includes ergonomics, risk and safety management, and accident analysis. Surabaya-Indonesia

in

September 2011. Her research interest includes ergonomics, risk and safety management, and accident analysis.



THE COLLISION ACCIDENT OF THE INDONESIAN RO-RO CAR-PASSENGER FERRY KMP. BAHUGA JAYA VERSUS SINGAPORE GAS CARRIER MV. NORGAS CATHINKA IN SUNDA STRAIT INDONESIAN INNOCENT PASSAGE Teguh Sastrodiwongso, Aleik Nurwahyudy, Renan Hafsar

Abstract The collision of Ro-Ro Car-Passenger Ferry KMP. Bahuga Jaya versus Gas Carrier MV. Norgas Cathinka on 26 September 2012 in Sunda Strait was investigated by NTSC. The Investigator Team in Charge have finished their investigation task and the Final Report . The factual findings and analysis show that short time after collision Bahuga Jaya started to list and then fully sank with 7 fatalities, but on the contrary Norgas Cathinka only suffering minor damage on its bow structure, none of her crew was suffered from injury. The main causal factor of collision is none of both vessel was presenting consistency in the implementation of Collision avoidance regulation. Keywords : vessel, accident, collision, safety.

1.

T

Introduction

he National Transportation Safety Committee of the Republic of Indonesia (NTSC) has conducted investigation into the collision accident of an Indonesian flag Ro-Ro Car-Passenger Ferry KMP. Bahuga Jaya versus an Singapore Flag Gas Carrier MV. Norgas Canthika. The serious accident occurred on 26 September 2012 in Sunda Strait ferry route crossing the west part of Indonesian water Innocent Passage-ALKI 1. Bahuga Jaya was collided on the forward starboard side wall structure. Unfortunately, short time later she started to list and fully sank. On the contrary Norgas Canthika only suffering minor damage on its bow structure, none of her crew was suffered from injury. The SAR of Indonesia rescued 206 survivors and recovered 7 fatalities i.e. 6 passengers and one crew (Chief Mate) of Bahuga Jaya. NTSC has issued Final Report of the Investigation (KNKT12-09-03-03). In addition to the conclusion of the accident, NTSC issued recommendations to the involved parties with aim to prevent recurrence in future. NTSC encourages all those parties to take safety action if any, they had carried out or were planning to carry out in relations to each safety issue relevant

Jurnal Teknik BKI

PROPULSION

to their organization. The material of this paper was based on the NTSC Final Report KNKT-12-09-03-03.

2.

The Investigation Into The Accident (National Transportation Safety Committee, 2013)

On 26 September 2012, NTSC had received the occurrence. Subsequently, NTSC dispatch investigation team to collect information to the directly involved parties. Bahuga Jaya Master, Chief Engineer, helmsman on duty and passengers were interviewed .the shore management of Bahuga Jaya also interviewed. NTSC investigator received copy of relevant document including Company SMS, maintenance report, passenger and cargo manifest, crew list and ship certificate. On 27 September 2012, NTSC Investigators attended the MV. Norgas Canthika while ship was anchored near to Suralaya Port, Banten. As the Master Chief Mate and Helmsman on duty were being interviewed by local Authority at shore, NTSC Investigators were interviewing remaining crews aiming their perspective to the accident. Copies of relevant document were obtained included ship’s log book, course recorder, master’s night order, and company’s procedure. With assistance from manufacturer’s Technician, VDR data was downloaded.

41


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Jurnal Teknik BKI

PROPULSION PROPULSION Additional information also provided by the Merak Ferry Port Management to obtained the STC’s ferry activities log data prior to the accident and the Head Office of Biro Klasifikasi Indonesia (BKI) i.e. Indonesian Ship Classification Society for ship’s data and its latest Class survey report. NTSC Investigators attended MV. Geulis Rauh to interview the Chief Mate who witnessing the collision. On 1 October 2012, NTSC conduct joint investigation with Maritime and Port Authority (MPA) of Singapore as Norgas Cathinka’s flagstate. NTSC Investigators and MPA Investigator attended Norgas Cathinka to interview the Master, Chief Mate and Helmsman on Duty. To obtain additional data of manoeuvring pattern of Ferries that servicing Merak – Bakauheni ferry route, on 1 – 4 January 2013 NTSC conduct survey. NTSC conducted survey to 25 ships that servicing the route with aim to identify the likelihood of ship manoeuvring when in crossing situation with the other ship.

The main particulars of the vessel : an overall length of 92.30 m, a moulded breadth of 16.20 m, a moulded depth of 5.23 m and a deadweight of 765 tonnes at its summer draft of 5.23 m. The vessel was owned and operated by PT. Atosim Lampung Pelayaran and had been operating on the Merak to Bakauheni ferry route since 2007. The vessel was registered and classed by Indonesian Ship Classification Society, Biro Klasifikasi Indonesia (BKI). The vessel had two car decks and one passenger accommodation deck. The car decks had a capacity of 200 vehicles of various types and the accommodation deck could carry 351 passengers. Machinery and Propulsion System

3.

The Technical Information Of The Vessels (National Transportation Safety Committee, 2013)

2 (two) unit four stroke, single acting, Stork Werkspoor 8TM410 Diesel engine were installed in the Twin Screw Bahuga Jaya as her main engines with a maximum continuous rating of 3,235 kW at 530 RPM respectively. The screw propellers were of controllable pitch propeller type (CPP) and the vessel was also fitted with a bow thruster. The service speed of the vessel was about 19 knots.

3.1.

KMP. Bahuga Jaya ex Tri Star 8 (Figure 1)

The Navigational and Telecommunication Equipment

Main Particulars of the Vessel KMP. Bahuga Jaya (IMO No. 7206392/Call sign YEBA) was an Indonesian flag Ro-Ro Car Passenger Ferry. She was of steel construction and was built in 1972 by Ulstein Mek. Verksted AS at their Ulsteinvik Yard, Norway.

Bahuga Jaya equipped with navigational equipment in comply with the Indonesian Safety Sstandard. Radio Facilities : VHF: Encoder DSC, DSC with Receiver, Radio Telefony; MF: Radiotelefoni; Navigational system & equipment : Secondary Means of Alerting; Navtex Receiver;COSPAS SARSAT; Radar transponder ; Standard Magnetic Compass & Spare; Means of Correcting headings & Barring; Nautical Chart & Nautical Publication; Global Navigation Satellite system Receiver AIS; Radar 9 GHz and secondary; Electronic Plotting Aid; Emergency Telephone; International Code of Signals The Cargo and Passenger Manifest

Figure 1 : KMP. Bahuga Jaya (National Transportation Safety Committee, 2013) Jurnal Teknik BKI Edisi 02 - Desember 2014

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At the time of accident, KMP. Bahuga Jaya carrying Passengers and 78 various type of vehicles. According to the passenger list, but there were only 12 registered passengers.


Vehicles onboard : Upper car deck : 10 unit motor cycles; 22 unit small cars; 11 unit trucks; Lower car deck: 17 unit medium size lorries; 18 unit heavy lorroes. 3.2. MV. Norgas Cathinka (Figure 2) Main Particulars of the Vessel MV. Norgas Cathinka (IMO No. 9370654) is a Singapore registered gas carrier. The ship is of steel construction and was built in 2009 by Taizhou Wuzhou Shipbuilding Industry Co Ltd at their Taizhou ZJ Yard, China. It has an overall length of 109.5 m, a moulded beam of 21.0 m a draught of 8.0 m and a displacement of 14,781 tonnes

The Navigational and telecommunication equipment The navigation bridge was equipped with navigational equipment consistent with SOLAS Requirement. This included an auto gyro pilot, ARPA equipped radars, GPS plotter, echo-sounder, AIS, ECDIS, VHF radios, satellite telephone and Furuno VR-3000 voyage data recorder (VDR). The Cargo Information At the time of the accident, MV. Norgas Cathinka was carrying Polymer Grade Propylene in Bulk with total of 3.045 MT. The cargo was loaded in Brazil and will be transported to China. The Ship Passage Plan Norgas Cathinka’s passage plan from Brazil to China was divided into 3 passages i.e. Brazil to Durban, South Africa (1st bunkering port), Durban to Singapore (2nd bunkering port) and Singapore to China.

Figure 2 : MV. Norgas Chatinka anchoring at Suralaya, Banten (National Transportation Safety Committee, 2013) At the time of accident, MV. Norgas Cathinka was owned by Taizhou Hull No. WZL0502 L.L.C and chartered by I.M Skaugen Marine Services Pte, Ltd, Norway. She was classed with Germanicher Lloyd (GL). The ship’s bridge and accommodation were located aft of four cylinder type ‘C’ cargo tanks that had a total capacity of 9,626 m3. At the time of the accident, the ship was carrying 3,045 MT of Polymer Grade Propylene that had been loaded in Brazil for delivery to China. The Propulsion and Machinery System Propulsive power was provided by two four stroke, single acting, Daihatsu 8DKM-28 diesel engines each with a maximum continuous rating of 2,500 kW at 750 RPM. Each engine was clutched into a reduction gearbox which, in turn, drove a fixed pitch propeller. The ship had a service speed of 13.5 knots at a shaft rotation speed of 190 RPM.

The passage plan from Durban to Singapore prepared on the 6 September 2012 was approved by the Master. The passage plan indicated that NC will transit Sunda Strait at Way-point 6 and 7. At the time of the incident, NC was proceeding towards Way-point 7. The passage plan’s information for travelling through Sunda Strait includes heavy crossing traffic and to maintain standing watch 1 or 2 (watch level) at the discretion by the Master. On this voyage through the strait, the Master decided to maintain standing watch 2.

4.

Indonesian Innocent Passage And Merak - Bakauheni Ferry Route (National Transportation Safety Committee, 2013)

The Merak to Bakauhe ferry route, crossing the Sunda Strait between the islands of Jawa and Sumatera, is Indonesia’s busiest passenger/vehicle ferry route (Figure 3). The Sunda Strait also sees the passage of a large number of domestic and international trading ships as the strait is part of one of three designated Indonesian Archipelagic Sea Lanes (ALKI) that are used by north/south bound ships when transiting through Indonesian waters. As a result, the British Admiralty navigational chart 2056 covering the Sunda Strait and its approaches contains the following warning ‘Mariners are warned ferries cross Jurnalthat Teknik BKI Edisi 02- Desember 2014


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Figure 3 : Indonesia Innocent Passage (National Transportation Safety Committee, 2013) Selat Sunda [Sunda Strait] between Bakauheni (5°52’S 105°45’E) in Sumatera and ports on the north coast of Jawa’. According to the statistics data issued by the Ministry of Transportation, there were 26,291 ferry trips from Merak to Bakauheni in 2011. This translates to about 76 trips per day or about 3 every hour. According to the statistical data, 1,400,986 people and 1,773,672 vehicles were transported by the various ferries operating on this route. The route is about 15 nautical miles in length and ferries normally complete the journey in about 2 to 3 hours. According to 2012 data, the route was serviced by 41 ships which were operated by 5 shipping companies. Ferry Port Management provides a Ship Traffic Controller (STC) whose main function is to control and supervise the arrival and departure of ferries at the ports. The STC is equipped with radar and AIS monitoring systems and uses frequency 8250 to communicate with the local ferries and channel 16 to communicate with other shipping.

5.

The Collision Accident (National Transportation Safety Committee, 2013)

1 Jurnal All Teknik times BKI referred to in the paper are local time, Edisi 02 - Desember 2014 Indonesian Western Time, (UTC+7, The time being kept on board Norgas Cathinka was UTC+8.

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At 03051 on 26 September 2012, Bahuga Jaya sailed from Merak bound for Bakauheni. The ferry was on a scheduled, regular, westbound crossing of Sunda Strait. The passage would be made at its usual speed of about 10 knots and would take about 2 hours. The master, chief mate and a helmsman were on the ferry’s bridge. The weather in the area was good with light to moderate winds and good visibility. The chief mate was on the look-out and the helmsman was on the con. The chief mate observing the route situation at the wing bridge. Meanwhile, Norgas Cathinka was approaching Sunda Strait from the south on a northeasterly course. The chief mate and a seaman were on the bridge. The chief mate was using the ARPA radar on a north-up, relative motion display on the 6 mile range scale. The centre of the display had been offset to enable the chief mate to see further in the ahead direction. At 0420, Norgas Cathinka was on a heading of 049 (T) and making good a course of about 051 (T) and a speed of about 12 knots. The ship was in a location about 2 Nmiles from Kandang Balak Island and there were a number of vessels in the area. The radar’s trails function was being used by the chief mate to continuously indicate the relative movement of targets. The traffic being monitored more closely was acquired either as an ARPA or an AIS target.


Figure 4 : Norgas Cathinka approached the Strait at 0400 (National Transportation Safety Committee, 2013) At the time, three eastbound radar targets on Norgas Cathinka’s port bow would have been of paramount interest (Figure 4). These vessels were on east-south-easterly courses and could have been ferries. They were between about one and three points on the port bow and about 3 to 4 miles distant. A target on a south-westerly course, about three points to starboard and over 2 miles off, was passing clear. Two westbound targets on the same bearing over 6 miles off had just started to appear on the radar display. At 0426, one of the eastbound targets (ARPA target 98 in Figure 4) crossed Norgas Cathinka’s bow more than 3 miles off. The other eastbound targets were also acquired (targets 99 and Caitlyn). At 0429, target 99 crossed Norgas Cathinka’s bow at a distance of more than 1.5 miles. The ARPA was indicating that Caitlyn would also cross ahead and clear of the ship. At 0432, Norgas Cathinka’s chief mate used the radar’s electronic bearing line (EBL) to check the bearing of one of the two westbound targets that had appeared on the display more than 12 minutes earlier. The target’s bearing was 075 (T) and its relative trail indicated that it would pass close to the ship. The target was 3.3 miles off and acquired as an AIS target. Its name, Bahuga Jaya, appeared on the radar display. The ferry was making good a course of about 285 (T) at a speed of 9.7 knots. Its closest point of approach (CPA) indicated nearly zero after about 11 minutes.

The ferry was on a collision course with the ship. At 0434, Norgas Cathinka’s chief mate acquired the other westbound target. This AIS target was also a ferry, Gelis Rauh, and the ARPA indicated it would pass about a mile astern. At 0436, target 100 crossed Norgas Cathinka’s bow at a distance of about 1 mile. Target 99 was nearly abeam to starboard and passing clear while target 98 was well clear. Bahuga Jaya was still on a collision course on a bearing of about 074 (T). At 0439½, Norgas Cathinka was in position 5 53.1’ S, 105 49.6’ E, just past a 031 (T) course alteration as per its passage plan. The ship was still on a heading of 049 (T) and Bahuga Jaya was 1.3 miles off. There had not been any appreciable change to its bearing which were now 072 (T). The ARPA predicted a CPA of 0.1 of a mile (i.e. a close quarters situation or collision) after 5 minutes. At about 0440, Norgas Cathinka’s chief mate decided to take action to avoid collision. Using the autopilot, he adjusted the heading order to 050 (T). At about the same time, Bahuga Jaya’s chief mate also decided to take action to avoid collision. He ordered port 20 and the helmsman executed his order. At 0440½, Norgas Cathinka’s heading was 050 (T). The chief mate then began adjusting the heading order further to starboard on the autopilot. At about the same time, Bahuga Jaya’s course change to port became apparent to him. Jurnal Teknik BKI Edisi 02- Desember 2014 Jurnal Teknik BKI Edisi 03-Agustus 2016

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PROPULSION PROPULSION By 0441, Norgas Cathinka’s heading was 055 (T) and turning to 060 (T) as set on the autopilot. The helmsman was standing near the steering stand and could see Bahuga Jaya’s change of course to port. The ferry was now less than a mile off. At 0442, Norgas Cathinka’s heading was 060 (T) and Bahuga Jaya was less than 0.7 of a mile and nearly ahead. Norgas Cathinka’s chief mate saw that the ferry was still turning to port. At about 0442½, Bahuga Jaya’s chief mate ordered hard a port. Norgas Cathinka was less than half a mile ahead. By this time, the ship’s chief mate had changed to hand steering mode and had turned the wheel to starboard to alter course more quickly. At 0443, Norgas Cathinka’s heading was 066 (T) and turning to starboard. Bahuga Jaya was 0.3 of a mile directly ahead of the ship and turning quickly to port. The two vessels were closing rapidly at a speed where they would meet in about 1 minute. Gelis Rauh, the other ferry, was half a mile away from the close quarters situation. It had altered course to port to keep clear of both vessels and pass further astern of Norgas Cathinka. At 0443¼, Bahuga Jaya’s chief mate made a hurried attempt to contact Norgas Cathinka on VHF radio channel 16. He called the ship’s name three times, but he received no response. Norgas Cathinka’s chief mate was still at the steering stand and he did not understand the radio call. At 0443¾, with Bahuga Jaya about 100 m away, he turned the wheel hard over to starboard. At 0444¼, Norgas Cathinka’s heading was 135 (T) and turning quickly to starboard. A few seconds later, the port bow of the ship collided with Bahuga Jaya’s port side, aft of the bridge. At 0444½, aware of the collision, Gelis Rauh made a distress (Mayday) call on VHF radio channel 16. At 04.44.57, Norgas Cathinka heading 161 at 7 knot and maintain its heading and speed. MV. Bahuga Jaya started to listJurnal to its Port. Teknik BKI The master of Bahuga Jaya went to Edisi 02 - Desember 2014

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the bridge to identify the event. After assessing the situation, the Master requesting assistance to the Ship Traffic Controller station of Bakauheni Port. About 10 Ferries approaching the Bahuga Jaya position to provide assistance. The Navy boat and Marine Police ship also approaching to secure the location. Bahuga Jaya continued to list. The master ordered to abandon the ship and ask the crew provide assistance to passengers. Number of ferries that crossing the route approached bahuga jaya to provide assistant to the survivors. Local Marine Police and Navy boats also presents on site to help in securing the collision site. One marine police boat approaching Norgas Cathinka and requesting the ship to stop. Later the boat berthed alongside the ship. At 05.25, AIS of MV. Bahuga Jaya no longer appears. The ship fully sank at 05 49.24 S/105 53.29 T at 79 m deep. At 05.30, after moving 5 Nm from the collision position, Norgas Cathinka alters her course to the starboard and returns to the collision position soon after drop its anchor in the area.

6.

NTSC Analysis (National Transportation Safety Committee, 2013)

6.1.

Action to avoid the Collision

At 0420 on 26 September 2012, Norgas Cathinka was approaching the part of Sunda Strait where ferries frequently cross the strait in an east-west direction between Merak and Bakauheni. Shortly thereafter, the ship encountered the crossing traffic that could be expected there from both directions. Rule 15 of the COLREGS (Crossing situation) states : When two power-driven vessels are crossing so as to involve risk of collision, the vessel which has the other on her own starboard side shall keep out of the way and shall, if the circumstances of the case admit, avoid crossing ahead of the other vessel. Therefore, the northbound Norgas Cathinka was required to keep out of the way of a westbound vessel on its starboard side if a risk of collision was involved. Similarly, an eastbound vessel on the ship’s port side was required to keep out of its way if there was a risk of collision.


On 26 September 2012, Norgas Cathinka encountered five crossing vessels, three eastbound and two westbound. All the eastbound vessels crossed ahead of the ship, the closest crossing about 1 mile from its bow. Given the area, traffic, weather and the size, type and speed of the vessels involved, it was not considered that risk of collision existed, and no avoiding action was necessary. Rule 16 of the COLREGS (Action by give-way vessel) states : Every vessel which is directed to keep out of the way of another vessel shall, so far as possible, take early and substantial action to keep well clear.

Therefore, any action taken by Norgas Cathinka to avoid collision had to take into account compliance with the above Rule by Bahuga Jaya and Gelis Rauh. From about 0420, Norgas Cathinka’s chief mate monitored the eastbound crossing vessels. The last of the three vessels crossed the ship’s bow at 0436. It was not until 0432 that he checked the compass bearing of Bahuga Jaya and acquired it as a target followed, 2 minutes later, by the other target, Gelis Rauh. This indicates that there was significant delay in determining risk of collision with the westbound vessels, and with Bahuga Jaya in particular.

This meant that Norgas Cathinka was required to take appropriate action if a risk of collision was involved with either of the two westbound vessels. A developing situation involving a risk of collision with either vessel could have been identified as early as about 0420, shortly after they appeared on the radar display. Over the next 10 minutes, the risk of collision could have been determined and avoiding action taken.

While no action had been taken or considered with respect to the westbound vessels, Norgas Cathinka’s chief mate could have initiated action at 0436, when the eastbound vessel crossed the ship’s bow. However, even at 0437½, when the eastbound vessel was well clear and on the same bearing as Bahuga Jaya, no action had been taken on board Norgas Cathinka.

The first vessel, Bahuga Jaya, remained on a nearly steady compass bearing indicating risk of collision. The slightly opening bearing of the other vessel, Gelis Rauh, indicated that it would pass astern of the ship but would still need to be closely watched. Appropriate action taken by a give-way vessel must take into account any action by the stand-on vessel. Rule 17 of the COLREGS (Action by stand-on vessel) states: (a)(i) Where one of two vessels is to keep out of the way the other shall keep her course and speed. (a)(ii) The latter vessel may however take action by her manoeuvre alone, as soon as it becomes apparent to her that the vessel required to keep out of the way is not taking appropriate action in compliance with these Rules. (b) When from any cause, the vessel required to keep her course and speed finds herself so close that collision cannot be avoided by the action of the give-way vessel alone, she shall take such action as will best aid to avoid collision. (c) A power-driven vessel which takes action in a crossing situation in accordance with sub-paragraph (a)(ii) of this Rule to avoid collision with another power-driven vessel shall, if the circumstances of the case admit, not alter course to port for a vessel on her own port side. (d) This Rule does not relieve the give-way vessel of her obligation to keep out of the way.

It was not until after 0440, that Norgas Cathinka’s course was altered to starboard. In the circumstances, this action was neither early nor substantial and, hence, was not appropriate. After more than 2 minutes, the further action taken to alter course quickly was probably taken in confusion and panic with the collision imminent. Bahuga Jaya’s chief mate took action to avoid collision at about 0440, the same time as Norgas Cathinka’s course alteration was started. However, Bahuga Jaya’s course was altered to port and this was not consistent with Rule 17. According to the survey result, most of the ship officers aware that the ferry route was also crossed by numbers of foreign ship. In some occasion, they noted that the bigger ship was tending to reluctantly alter neither their course nor the speed. Most of the ferry Deck Officer state that the ferry have more ability to manouvre or reduce the speed instantly. Therefore they tend to avoid the bigger or foreign ship by altering its course more likely to aim the stern. Bahuga Jaya’s chief mate had probably concluded that Norgas Cathinka would maintain its course. It is also possible that he may have taken such action in the past in similar circumstances and that this may not be uncommon on board ferries in the area. Other than Bahuga Jaya’s chief mate’s brief attempt to contact Norgas Cathinka about a minute before the collision, there was no communication betweenJurnal the ships. Rule 34 of Teknik BKI Edisi 02- Desember 2014


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PROPULSION PROPULSION the COLREGS requires that whistle signals, which may be supplemented by light signals, be used by ships when taking action to avoid collision. Neither Norgas Cathinka nor Bahuga Jaya made any whistle or light signals. However, given the avoiding action taken on board both vessels, it is unlikely that the signals could have prevented the collision.

(BA 2056) in the centre of Sunda Strait states ‘FERRIES (see Note)’. The note on the chart states the following: SELAT SUNDA – FERRIES Mariners are warned that ferries cross Selat Sunda between Bakauheni (5⁰52’S 105⁰45’E) in Sumatera and ports on the north coast of Jawa.

As a give-way vessel, Norgas Cathinka had a number of options available for taking action by altering its course and/or speed. After assessing the situation after 0420, the chief mate could have reduced the ship’s speed to allow the crossing traffic to pass ahead of it. This could have been the most effective action but it is unlikely that the chief mate considered a speed reduction. He knew the main engine was not ready for immediate manoeuvre, the engine room was not manned and the master was asleep in his cabin.

The Admiralty Sailing Directions (Indonesia Pilot, Volume 1) provides further information and guidance for transiting Sunda Strait. Under the title ‘Hazards’, it states:

Alternatively, to achieve the same result as a speed reduction, Norgas Cathinka could have been turned around to a reciprocal course for a short time. This could have been done by turning to starboard in ample time, to avoid confusing the three eastbound crossing vessels on the port side. However, the lack of early assessment and action resulted in Norgas Cathinka’s chief mate finding himself in a complicated traffic situation. Within a period of less than 20 minutes, five crossing vessels would pass close to the ship. In this situation, the chief mate did not take the urgent action that he could have taken. Instead, as discussed above, the action he took was too little and too late. The situation was further complicated when Bahuga Jaya’s course was altered to port by its chief mate. While the collision was the direct result of actions on both vessels that were inappropriate or inconsistent with the COLREGS, a number of underlying factors influenced those actions. 6.2

The Passage Plan of Norgas Canthika (National Transportation Safety Committee, 2013)

Norgas Cathinka’s sailed from Durban, South Africa, about 10 days before its transit of Sunda Strait. The ship would therefore be making landfall after a long ocean passage and would transit a narrow passage where the charted hazards include rocks and shoals. In addition, crossing traffic can be expected in Sunda Strait. A notation on the chart Jurnal Teknik BKI Edisi 02 - Desember 2014

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Ferries ply on a regular basis at the E end of Selat Sunda between Merak (5⁰56.00’S 105⁰59.70’E), Jawa and Panjang (5⁰38.03’S 105⁰18.99’E), Sumatera; also between Bakauheni (5⁰52.30’S 105⁰45.30’E), Sumatera, and ports on the N coast of Jawa. Therefore, there is sufficient guidance for transiting ships with regard to crossing traffic in Sunda Strait. A ship’s passage plan should take into account this guidance and the master must have preparations in place for encountering crossing traffic and other hazards that can always be expected. Norgas Cathinka’s passage plan contained the following information for course leg through Sunda Strait. Normal sea watch. Follow COLREGs. Primary fixing method - radar, secondary - GPS. Plot ship’s position every 30 minutes. Keep sharp look-out. Ship’s squat 0.5 m. PI=1.3’ to P.Panjurit. Heavy traffic crossing course. Standing watch 1 or 2. ‘Standing watch 1 or 2’ for a ‘normal sea watch’ meant an officer of the watch at all times and a duty seaman only at night. There was no additional planning for transiting Sunda Strait. The master did not intended to be present on the bridge for the transit. His night orders on 25 September were similar to the previous nights with no specific guidance for Sunda Strait or crossing traffic. He required a minimum CPA of 2 miles and that he should be called if in doubt. There was no mark on the chart indicating that he required to be called at any particular place or time. In addition, there was no plan to either have the main engine on standby or the engine room to be manned. This would have ensured that a change in the ship’s speed was not only immediately possible at any time but that there was no doubt in the mind of the officer of the watch in this regard.

watch level 1 or two, he was not fully expected with the complexity of the ferry route. Before the accident happen, there were 6 ships that was in Technical Journal of Classification and Independent Assurance crossing situation. The bridge was manned in ‘Standing watch 1 or 2’ for a ‘normal sea watch’ compliance with passage plan of standing watch meant an officer of the watch at all times and a level 2. duty seaman only at night. There was no additional PI=1.3’ to P.Panjurit. Heavy traffic crossing course. Standing watch 1 or 2.

Bakauheni Port

Merak Port

Figure 5: Typical Merak – Bakauheni Ferry Passage (National Transportation Safety Committee, 2013) Figure 5 : Typical Merak – Bakauheni Ferry Passage (National Transportation Safety Committee, 2013)

The Norgas Cathinka passage plan indicating that the ship transit Sunda Strait at way point 6 - 7. The passage plan at way point-6 provides information for travelling through the strait includes normal sea watch, follow the COLREG and heavy crossing traffic course. The master had been crossing the Sunda strait for several times. He was aware that the ship would transit heavy ferry traffic. However, when the Master decides to maintain standing watch level 1 or two, he was not fully expected with the complexity of the ferry route. Before the accident happen, there were 6 ships that was in crossing situation. The bridge was manned in compliance with passage plan of standing watch level 2. To determine the standing level, the company has issued the company poster 037 of instruction for the watch at sea, bridge watch composition. The company poster states the description of sea and traffic state in which standing level need to be held from level 1 to level 5. Watch level 5 is purposed for Port Arrival/Departure or confined waters in restricted visibility and high traffic density. Watch level 5 requires the bridge to be manned by 6 persons comprising the master, two navigating officers, helmsman and lookout. By adopting fully manned bridge, any risk or hazard that may endanger ship could have been easily identified. When determining watch level, the master of Norgas Cathinka should consider any notification listed including hazard and risk that may exist so the ship would pass the area safely. According the policy, the master should have consider to determine to maintain watch level 5 when the ship transiting the ferry route.

6.3.

Communication Ship to Ship (National Transportation Safety Committee, 2013)

Generally, ship’s approaching each other on reciprocal course course do not communicating each other but rely on their compliance wiht the COLREG and the usual practise of good seamanship. According to the survey result, it is more likely that the ferries were tend to established communication to the other ferries or other ship in determining how both ships crossing or passing. At 0443, the chief mate of Bahuga Jaya was calling Norgas Cathinka to have their attention in regard with crossing situation. The chief mate was stating the Norgas Cathinka for three times repeteadly. The radio communication was made at the time both ship had started turning and at a distance of 0,2 Nm. The Chief Mate and Helmsman of Norgas Cathinka heard about the calling but could not understand about the request. At that time, both ships still maintain their turning and speed. The communication was made when a potential collision became apparent. When the chief mate saw the green light of the Norgas Cathinka and subsequently order the helm to port, he was in doubtful with the Norgas Cathinka’s manoeuvre. Jurnal Teknik BKI Edisi 02- Desember 2014


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PROPULSION PROPULSION Hence, he called the Norgas Cathinka to confirm their manoeuvre intention. As the calling was not responded, the chief mate of Bahuga Jaya decided to maintain it speed and keep turning hard to port.

inform the situation and control the ship movement. STC had small coverage to monitor all Sunda strait. STC should have more authorities to inform about situation that might risk ferry operation.

He should have utilise the VHF radio to confirming the other ship manoeuvre before he ordered to turn and satisfy his doubt.

7.

The chief mate of Norgas Cathinka was not expected that the Bahuga Jaya would turn to port. He was relied to the other ship compliance with the COLREG. 6.4.

Merak – Bakauheni Route FERRY TRAFFIC Management (National Transportation Safety Committee, 2013)

According to the ferry traffic data, number of ferry servicing the Merak – Bakauheni Route has been increasing. In 2011, the route was serviced by 33 ships comprising 22 ships were operational and 11 others scheduled for routine maintenance or annual inspection. Data 2012 indicating that the route was serviced by 41 ship comprising 33 ships operational and 7 others for routine and annual inspection. The trip productivity also indicating an increment. In 2006, total ferries trip in the particular route was 42.700 trips or 117 trips per day. The number had been increased in 2011, indicating by total of 57.248 trips or 156 trips per day was produced. Hence, in average there were 6-7 ship was servicing the route in every hour. There were also number of facilities in area near of Sunda Strait i.e.: steam generated power plant Suralaya which rely on coal supply carried by barges, and other factories which also demanding supply through ship transport. On the other side, as innocent passage, ALKI 1 would always be transited by international voyage. When Norgas Cathinka approached the Merak - Bakauheni ferry route, there were 5 other ships crossing its heading. Number of other ship was also had been identified manoeuvring within the area. Local Ferry Port Authority has established Ship Traffic Controller (STC) with limited capability STC main objective is to control all ferry traffic. To maintain the safe passage on the area, there should be a traffic management as it to Jurnal Teknik BKI Edisi 02 - Desember 2014

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CONCLUSION

a) Main Casual Factor the Collision Accident According to the evidence available, the main causal factor of collision is none of both vessel was presenting consistency in the implementation of Collision avoidance regulation. The following factors has been identified to be contributes to the action states above. b) Contributing Factors • After ship #100 pass clear ahead Norgas Cathinka, the chief mate of Norgas Cathinka was not sufficiently utilise time available to take a clear and substantial action to avoid collision. The course alteration was to slow to indicates ship movement to the other ship. • The Bahuga Jaya’s chief mate had made assumption based on scanty information that there was no significant course alteration made by Norgas Cathinka. Hence, he took action to alter helm to port to avoid collision; • Bahuga Jaya action to alter its course to port was not consistent with the collision avoidance regulation; • The Master of Norgas Cathinka through his night order was not provide sufficient guidance to the Chief Mate to safely transit the way point. The night order was not sufficiently adopt the risk notification provided in the chart. • The Norgas Cathinka master’s discretion to maintain watch standing level 1 or 2 on heavy traffic ferry route was not consistent with the ship procedure. Hence when the ship on the multiple risk of collision, no sufficient guidance provided to the bridge crew to adequately maintain watchkeeping and lookout. • Communication made from Bahuga Jaya was not taken at appropriate time and insufficiently broadcar c) Other Factor Ferry traffic had resulting both ship in multiple risk of collision.


REFERENCE National Transportation Safety Committee (2013), Final Report KNKT-12-09-03-03, Investigation Into the Collision Between The Indonesian Ro-ro Ferry MV. Bahuga Jaya and Singapore Gas Carrier MV. Norgas Cathinka in Sunda Strait (4 Nm eastern Rimau Balak Island), Indonesia 26 September 2012.

Teguh Sastrodiwongso, Member of the Investigator Team in Charge, National Transportation Safety Committee (NTSC) - Indonesia, e-mail : [email protected] Aleik Nurwahyudy, Member of the Investigator Team in Charge, National Transportation Safety Committee (NTSC) - Indonesia, e-mail : [email protected]

Renan Hafsar, Member of the Investigator Team in Charge, National Transportation Safety Committee (NTSC) - Indonesia, e-mail: [email protected] Jurnal Teknik BKI Edisi 02- Desember 2014 Jurnal Teknik BKI Edisi 03-Agustus 2016

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Contact address : Statutory Division PT. Biro Klasifikasi Indonesia (Persero) Jl. Yos Sudarso 38-40, Tanjung Priok, Jakarta – 14320 Phone : (62-21) 4301017, Fax. : (62-21) 4393 6175 e-mail : [email protected]

APLIKASI BKI-GREENPADMA SEBAGAI SOLUSI PENERAPAN REGULASI ENERGI EFISIENSI Tribuana Galaxy

Abstract International maritime shipping was appraised to have emitted 1046 million tonnes of CO2 in 2007, representing 3.3 per cent of the world global CO2 emission. It is foreseen to increase by factor two to three in 2050 in absence of reduction action (Buhaug, et al., 2009). In line with those issue, the International Maritime Organization (IMO) has required implementing energy efficiency instruments included in Chapter 4 of MARPOL Annex VI. Hence, having Ship Energy Efficiency Management Plan (SEEMP) for all existing ships over 400 GT and attained Energy Efficiency Design Index (EEDI) for new building of several ship types are mandatory from 1st January 2013. To address these challenges, BKI has released the newest service namely the issuance of the Statement of Verification (SoV) for EEDI and SEEMP, including EEOI. This service is robustly supported by the GreenPADMA software to help the calculation and verification for the index of EEDI and EEOI. This calculator software was mainly equipped by reliable features that have been updated by using the latest regulation either from IMO or IACS. Some examples for these features are: the software provides 12 (twelve) different ship types in accordance with the newest regulation requierement; it has specification to calculate power from conventional propulsion system, dual fuel engine, as well as diesel electric. In addition, the software also able to calculate the installation of innovative technology in ships which was expected to facilitate the application of the energy efficiency means. By providing those new service, BKI as a state-owned classification society shows the commitment to continuously assist customers especially the shipping industries, in order to implement new regulations effectively through the development of support tools. Keywords : IMO, AnnexVI, EEDI. SEEMP, GreenPADMA, Statement of Verification

1.

S

Pendahuluan

alah satu konvensi internasional yang selalu menjadi perbincangan hangat di dunia adalah konvensi yang mengatur mengenai pencemaran udara di lingkungan laut. Konvensi tersebut dikeluarkan oleh IMO (International Maritime Organization) dan diakomodir pada regulasi MARPOL 73/78 Annex VI. Seiring dengan perkembangan isu pemanasan global, maka per 1 Januari 2013 IMO mengamandemen Annex VI dengan menambahkan regulasi efisiensi energi terkait upaya untuk membatasi emisi CO2 baik untuk kapal bangunan baru maupun bangunan lama. Upaya pembatasan emisi CO2 pada regulasi tersebut selanjutnya ditunjukkan dengan penerbitan sertifikat efisiensi energi yaitu IEEC (International Energy Efficiency Certificate). Konsep utama dari regulasi efisiensi energi adalah dengan mengurangi konsumsi bahan bakar karbon pada kapal, sehingga emisi CO2 akan berkurang. Skema regulasi tersebut dirangkum sebagai berikut :

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PROPULSION

53

a. SEEMP (Ship Energy Efficiency Management Plan). SEEMP merupakan skema pengurangan emisi dengan menitik beratkan pada manajemen operasional kapal sehingga konsumsi bahan bakar dapat dioptimalkan. SEEMP berbentuk manual atau booklet yang berisi tentang perencanaan manajemen operasional dan wajib tersedia diatas kapal, baik untuk bangunan baru maupun lama. Manual tersebut harus dilengkapi dengan indikator emisi guna mengkuantifikasi dan memonitor efektifitas perencanaan manajemen operasional yang telah dibuat. Hingga saat ini, jenis dan metode indikator emisi untuk SEEMP masih dibebaskan untuk dikembangkan oleh pemilik maupun operator kapal. Namun, IMO mewacanakan untuk mewajibkan penggunaan EEOI (Energy Efficiency Operation Indicator) sebagai indikator emisi. EEOI merupakan indeks besaran emisi CO2 yang dihitung dari fungsi total konsumsi bahan bakar dibanding dengan jumlah kargo yang diangkut pada satu satuan jarak pelayaran kapal.


Jurnal Teknik BKI


Jurnal Teknik BKI

PROPULSION PROPULSION b. EEDI (Energy Efficiency Design Index). Berbeda dengan SEEMP, regulasi ini mengatur mengenai optimalisasi desain pada kapal berkaitan dengan efisiensinya dan diukur secara kuantitatif dengan menggunakan suatu indeks desain. Karena pengkajiannya hanya dilakukan pada desain, maka regulasi ini hanya berlaku untuk kapal bangunan baru.

2.

Regulasi Efisiensi Energi Pada Kapal

The fourth Assessment Report of Intergovernmental Panel on Climate Change (IPCC, 2007) menyatakan bahwa peningkatan temperature sebesar 2°C dapat menyebabkan dampak yang bersifat katastropik terhadap kondisi iklim dan lingkungan secara global. Sehingga untuk menjaga stabilitas temperatur tersebut, emisi GHG (Green House Gasses) harus diturunkan sebesar 50 hingga 85 persen pada tahun 2050 dengan acuan level GHG saat ini. Komponen GHG utama yang dikeluarkan oleh aktivitas kapal melalui gas buang adalah karbon dioksida (CO2). Hal ini dikarenakan, dalam konteks kuantitas dan potensi efek gas rumah kaca, CO2 disinyalir dapat menyebabkan dampak yang besar terhadap lingkungan. Sedangkan komponen gas buang lain dianggap mempunyai kontribusi yang lebih rendah terhadap lingkungan dikarenakan siklus hidup di udara yang cenderung lebih pendek sehingga lebih cepat terurai. Berangkat dari landasan tersebut, IMO melakukan studi terhadap efek gas rumah kaca yang diakibatkan oleh aktivitas dunia maritim khususnya kapal. Studi tersebut terangkum dalam IMO GHG Study yang telah dilaksanakan secara berkesinambungan dari tahun 2000 hingga saat ini. Dan pada IMO GHG Study yang kedua tahun 2009, IMO mulai menyusun pemberlakuan regulasi yang mengatur upaya pengurangan konsumsi bahan bakar karbon sehingga dapat mengurangi emisi gas buang berupa CO2. Konsep dasar dari regulasi tersebut adalah dengan optimalisasi penggunaan energi pada kapal baik ditinjau pada level desain maupun operasional. Regulasi pada level desain adalah EEDI, sedangkan yang mengatur operasional kapal adalah SEEMP (Ship Eficiency Management Plan). Kedua item mandatory tersebut termaktub dalam MARPOL 73/78 Annex VI “International Convention on the Prevention of Pollution from Ships” dan mulai diberlakukan per 1 Januari 2013. IMO menyatakan bahwa reJurnal Teknik BKI Edisi 02 - Desember 2014

54


gulasi tersebut akan terus dikembangkan sejalan dengan peningkatan fokus dunia terhadap isu efek rumah kaca. Konsep dasar mengenai regulasi EEDI dan SEEMP tersebut selanjutnya akan dideskripsikan pada penjelasan berikut dengan mengutip resolusi IMO-MEPC, adapun pengecualian dan pernyataan tambahan akan disebutkan sumber pustakanya. -- Resolution MEPC.212 (63) ; 2012 Guidelines on the method of calculation of the attained Energy Efficiency Design Index (EEDI) for new ships -- Resolution MEPC.213 (63) ; 2012 Guidelines for the development of a Ship Energy Efficiency Management Plan (SEEMP) -- MEPC.1/Circ.684 ; 17 August 2009 Guidelines For Voluntary Use Of The Ship Energy Efficiency Operational Indicator (EEOI) 2.1.

Energy Efficiency Design Index (EEDI)

EEDI merupakan sebuah regulasi yang menerapkan mekanisme berbasis performa desain kapal dan memberikan kebebasan bagi pemilik maupun operator kapal untuk menerapkan berbagai desain ataupun teknologi terapan guna mencapai penghematan energi pada level tertentu. Tujuan utama regulasi ini adalah mendorong penerapan teknologi baik yang sudah proven maupun yang masih novel pada pendesainan dan pembangunan kapal. EEDI merupakan pendekatan bersasis desain, sehingga indeks efisiensi untuk dua kapal identik atau kapal sister dapat bernilai sama. Hal ini disebabkan karena indeks yang didapat berasal dari desain kapal saat dibangun dan mengesampingkan kondisi operasional kapal. EEDI akan diberlakukan untuk kapal dengan gross tonnage 400GT atau lebih dan indeks EEDI (g/(t.nm)) dapat dihitung dengan rumus dibawah ini.

Technical Journal of Classification and Independent Assurance Dimana: CF

Dimana: CF

Vref capacity

P

SFC

dari gkan ukan lebih

fc fl

fl

Faktor koreksi berkaitan dengan peralatan kapal transport Simbol seperti work. crane ,dll Faktor koreksi

[-]

pembagi untuk mesin[-] utama f l atau 𝑔𝐶𝑂� Nm/jm : atau Main engine(s), mesin bantu atau Auxiliary engine(s), berkaitan dengan Selanjutnya nilai EEDI harus lebih rendah dari 𝑔 𝑓𝑢𝑒𝑙 knot dan penggunaan bahan bakar peralatanenergy kapal efisiensi dilambangkan teknologi reference line yang dipersyaratkan oleh IMO. capacity Kapasitas kapal yang terhadap emisi CO2 seperti crane ,dllSelanjutnya oleh subscripts; ME, AE, dan eff. EEDI5 dapat Rumusan tersebut pada dasarnya dibagi menjadi diatur sesuai dengan parameter utamarasio yaitu;perbandingan [a] emisi CO2antara oleh mesin disimpulkan sebagai total emisi Kecepatan masing masing jenisNm/jm : induk atau Main Engine, [b] dan [c] emisi CO oleh work. 2 kapal Selanjutnya nilai EEDI harus lebih rendah dari CO yang dihasilkan oleh kapal per satuan transport knot 2 Vref Faktor

P

Kecepatan konversi jenis

Power baik untuk

Kapasitas kapal yang mesin induk dan diatur sesuai mesin dengan bantu maupun output power yang masing masing jenis dihasilkan oleh kapal energi efisiensi Power baik untuk kW terapan mesin induk dan SFC Spcific Fuel Oil mesin bantu Consumption maupun fi output powerFaktor yangkoreksi elemen desain kapal dihasilkan oleh yang dihitung energi efisiensi tergantung dari tipe terapan kapal dan jenis 𝑔 notasi : Oil ice class Spcific Fuel fw Faktor koreksi yang 𝑘𝑊ℎ Consumption

kW

𝑔 𝑘𝑊ℎ [-]

[-] menindikasikan fi Faktor koreksipenurunan [-] kecepatan kalap elemen desain kapal akibat kondisi yang dihitung seaway (wave and tergantung dari windtipe condition) fi dan jenis Faktor kapasitas [-] kapal feff : ice class Faktor teknologi [-] notasi energy efisiensi fw Faktor koreksi yang [-] � terapan dan indeks EEDI � � dapat dihitung dengan menindikasikan �.�� fc Faktor koreksi [-] kapasitas kubik rumus dibawahpenurunan ini.

fi feff

:

𝑔𝐶𝑂� 𝑔 𝑓𝑢𝑒𝑙

Faktor konversi jenis bahan bakar terhadap emisi CO2

kecepatan kalap akibat kondisi seaway (wave and wind condition) Faktor kapasitas Faktor teknologi energy efisiensi terapan Faktor koreksi kapasitas kubik Faktor koreksi berkaitan dengan peralatan kapal seperti crane ,dll

[-] [-]

[-] [-]

mesin bantu, pengurangan emsisi CO 2 oleh yang IMO. reference line[d]yang dipersyaratkan dapat dicapai dengan penerapan teknologi, dan Rumusan tersebut pada dasarnya dibagi menjadi Salah satu topside module ada work. pada FSO adalah 5 parameter pembagi atau yang transport Simbol parameter utama yaitu; [a] CO oleh mesin untuk mesin utama atau Mainemisi engine(s), 2mesin crane. Konstruksi crane, terutama pada bagian pondasi bantu atau Auxiliary engine(s), dan induk atau Main Engine, [b] dan [c]penggunaan emisi COharus 2 oleh crane (crane seating) haruslah kuat, karena selain teknologi energy efisiensi dilambangkan oleh mesin bantu, pengurangan COharus 2 yang menumpu struktur, [d] di atasnya, pondasi emsisi crane juga subscripts; ME AE , dan eff. Selanjutnya EEDI dapat dapat dicapai dengan penerapan teknologi, dan kuat menerima beban operasional dan beban-beban disimpulkan sebagai rasio perbandingan antara total lain parameter pembagi atau2010). transport emisi CO2FSO yang(Sujiatanti, dihasilkan oleh kapal perwork. satuan Simbol akibat gerakan transport work.utama atau Main engine(s), mesin untuk mesin bantu atau Auxiliary𝐶𝑂engine(s), dan penggunaan � 𝑒𝑚𝑖𝑠𝑠𝑖𝑜𝑛 𝐸𝐸𝐷𝐼 = efisiensi dilambangkan oleh teknologi energy 𝑡𝑟𝑎𝑛𝑠𝑝𝑜𝑟𝑡 𝑤𝑜𝑟𝑘 subscripts; ME, AE , dan eff. Selanjutnya EEDI dapat 2.2. Ship sebagai Energy Efficiency Management Plan disimpulkan rasio perbandingan antara total 2.2. (SEEMP) Ship Energy Efficiency Management Plan (SEEMP) dan Energy Efficiency Operational emisi CO2 yang dihasilkan oleh kapal per satuan Indicator (EEOI) dan Energy Efficiency Operational Indicator (EEOI) transport work. SEEMP merupakan regulasi berbasis operasional SEEMPyang merupakan operasional yang memenitik regulasi beratkan berbasis pada performa 𝐶𝑂�monitoring 𝑒𝑚𝑖𝑠𝑠𝑖𝑜𝑛 nitik beratkan pada monitoring performa aktual kapal 𝐸𝐸𝐷𝐼 = aktual kapal pada saat berlayar dengan pada 𝑡𝑟𝑎𝑛𝑠𝑝𝑜𝑟𝑡 𝑤𝑜𝑟𝑘 memperhitungkan motode-metode yang mungkin saat berlayar dengan memperhitungkan motode-metode diterapkan untuk mengurangi konsumsi energi. yang mungkin diterapkan untuk mengurangi konsumsi Implementasi SEEMPEfficiency juga memberikan manfaat Plan 2.2. Ship Energy Management energi.langsung Implementasi operator SEEMPdan juga memberikan manfaat pemilik kapal berupa (SEEMP) kepada dan Energy Efficiency Operational langsung kepada operator dan pemilik pengurangan biaya operasional sebagaikapal akibatberupa dari peIndicator (EEOI) berkurangnya konsumsi sebagai bahan bakar ngurangan biaya operasional akibat karena dari berkupenghematan energi. Berkebalikan dengan EEDI, rangnya konsumsi bahan bakar karena penghematan SEEMP merupakan regulasi berbasis operasional energi. Berkebalikan dengan EEDI, SEEMP menunjukkan yang menitik beratkan pada monitoring performa bahwa setiap kapal mempunyai pola efisiensi yang berbeaktual kapal pada saat berlayar dengan da dikarenakan beroperasi pada kondisi lingkungan yang memperhitungkan motode-metode yang mungkin berbeda. Dengan kata lain, jika sister ship dapat mempuditerapkan untuk mengurangi konsumsi energi. nyai EEDI yang sama, namun pada SEEMP sudah pasti akan Implementasi SEEMP juga memberikan manfaat berbeda.

langsung kepada operator dan pemilik kapal berupa pengurangan biaya operasional sebagai akibat dari SEEMP diwajibkan untuk semua kapal baik bangunan baru berkurangnya konsumsi bahan bakar karena maupun bangunan lama dengan kapasitas 400 GT keatas. penghematan energi. Berkebalikan dengan EEDI, Garis besar penerapan SEEMP sebagaimana dilustrasikan pada gambar 1, meliputi 4 siklus fase yang saling ketergantungan yaitu; perencanaan (planning), penerapan metode pengurangan energi (implementation), monitoring, dan evalusi atau improvement. Dikarenakan 4 siklus fase ini saling ketergantungan, maka jika terdapat perubahan disalah satu fase, maka akan mempengaruhi fase yang lain.

Selanjutnya EEDI harus lebih rendah line dari Selanjutnya nilai nilai EEDI harus lebih rendah dari reference reference line yang dipersyaratkan oleh IMO. yang dipersyaratkan oleh IMO. Rumusan tersebut pada Rumusan tersebut pada dasarnyautama dibagi menjadi dasarnya dibagi menjadi 5 parameter yaitu; [a] emi-5 parameter utama yaitu; [a] emisi CO oleh si CO2 oleh mesin induk atau Main Engine, [b]2dan [c]mesin emisi Tahap pertama adalah planning yang meliputi penentuan induk atau Main Engine, [b] dan [c] emisi CO oleh kondisi awal kapal saat sebelum mengimplementasikan 2 CO2 oleh mesin bantu, [d] pengurangan emsisi CO2 yang mesin bantu, [d] pengurangan emsisi CO yang 2 SEEMP dan penentuan target efisiensi yang diharapkan. dapat dicapai dengan penerapan teknologi, dan parameter dapat dicapai dengan penerapan teknologi, dan parameter pembagi atau transport work. Simbol untuk mesin utama atau Main engine(s), mesin bantu atau Auxiliary engine(s), dan penggunaan teknologi energy efisiensi dilambangkan oleh



55

MP

tahunan pelayaran suatu kapal, maka EEOI dapat dirumuskan sebagai berikut:

Jurnal Teknik BKI


menunjukkan

bahwa

setiap

kapal

𝐴𝑣𝑒𝑟𝑎𝑔𝑒 𝐸𝐸𝑂𝐼 =

Berkaitan dengan regulasi MARPOL Annex VI

Dimana: i : j : CFj :

Planning

Evaluation

Implementation

D FCij mcargo

: : :

∑� ∑� 𝐹𝐶� × 𝐶�� ∑� 𝑚��,� × 𝐷�

Jumlah pelayaran Tipe bahan bakar Faktor konversi CO2 untuk jenis bahan bakar j Jarak pelayaran [nm] Konsumsi bahan bakar j pada pelayaran i Kargo yang diangkut kapal [tonnes] atau TEU atau n penumpang

3. Sertifikasi dan Verifikasi 3. SERTIFIKASI DAN VERIFIKASI

Berkaitan dengan regulasi MARPOL Annex VI mengenai pemberlakuan SEEMP dan EEDI, terdapat jenis sertifikat baru yang diterbitkan yaitu International Energy Efficiency Monitoring Certificate (IEEC). IEEC merupakan sertifikat statutoria yang Berkaitan dengan regulasi MARPOL Annex VI SEEMP menunjukkan bahwa setiap kapal akan diterbitkan kali oleh pemerintah atau Berkaitan dengan satu regulasi MARPOL Annex VIRecognized SEEMP menunjukkan bahwa setiap kapal mengenai pemberlakuan SEEMP dan EEDI, punyai pola efisiensi yang berbeda Gambar : Fase SEEMP Organization (RO) untuk tiap tiap kapal dan valid selaterdapat jenis sertifikat baru yang diterbitkan yaitu dapat dirumuskan sebagai berikut: International Energy Efficiency Certificate (IEEC). ma kapal masih beroperasi atau sepanjang umur kapal. ∑� 𝐹𝐶� × 𝐶�� IEEC merupakan sertifikat statutoria yang akan Pada metodeSertifikat 𝐸𝐸𝑂𝐼 = fase ini juga meliputi pendokumentasian diterbitkan satu kali oleh pemerintah atautersebut harus tersedia diatas kapal untuk keper𝑚�� × 𝐷 metode penghematan energiRecognized yang akan diaplikasikan luan dan audit (IACS, 2012). Organization (RO) untuk tiap tiapinspeksi kapal dan valid selama kapalmetode masih beroperasi atau EEOI digunakan pada sebagai kapal. indeks Tahapmonitoring kedua adalah implementasi sepanjang umur kapal. Sertifikat tersebut harus beberapa kali pelayaran misalnya monitoring metode yang sudah dideskripsikan pertama. kapal tersediapada diatas tahap kapal untuk keperluan Bagi inspeksi dan bangunan baru, IEEC akan dikeluarkan saat an pelayaran suatu kapal, maka EEOI dapat audit. (IACS, 2012) Tahap ketiga adalah monitoring yang merupakan upaya survey initial dengan syarat bahwa EEDI sudah diverifikasi muskan sebagai berikut: untuk mengetahui apakah metode diaplikasikan SEEMP telah tersedia diatas kapal. Sedangkan unBagiyang kapal telah bangunan baru, IEEC akanserta dikeluarkan ∑� ∑� 𝐹𝐶� × 𝐶�� survey initial dengan syarat bahwatuk EEDI sudahbangunan lama (exisiting ship) sertifikat terse𝐴𝑣𝑒𝑟𝑎𝑔𝑒benar 𝐸𝐸𝑂𝐼 =benar dapat memenuhisaattarget atau tidak. Hasil kapal ∑� 𝑚��,� × 𝐷� diverifikasi serta SEEMP telah tersedia diatas kapal. monitoring selanjutnya digunakan untuk mengevaluasi but akan diberikan pada survey International Air Pollution Sedangkan untuk kapal bangunan lama (exisiting na: SEEMP secara keseluruhan. ship) sertifikat tersebut akan diberikanPrevention pada survey (IAPP) intermediate atau renewal yang perta: Jumlah pelayaran International Air Pollution Prevention (IAPP) syarat SEEMP tersedia diatas kapal. Untuk kama, dengan : Tipe bahan bakar intermediate atau renewal yang pertama, dengan : Faktor konversisaat CO2 untuk bahan bakar Untuk ini, jenis metode untuk monitoring stantertentu syarat SEEMPbelum tersedia di diatas kapal. sus Untuk kasus seperti jika suatu kapal melakukan konversi j tertentuterdapat seperti jikawacana suatu kapaljika melakukan konversi darisasi oleh IMO. Namun, sudah mayor, maka IEEC harus dibuat ulang menyesuaikan : Jarak pelayaran [nm] mayor, maka IEEC harus dibuat ulang : Konsumsi j pada pelayaranregulasi i IMObahan akanbakar mengeluarkan berkaitan dengan indeks dengan menyesuaikan dengan kondisi kapal yang terbaru.kondisi kapal yang terbaru. : Kargo yang diangkut kapal [tonnes] atau o monitoring yaitu Energy Efficiency Operational Indicator TEU atau n penumpang penunjang penerbitan IEEC (EEOI). EEOI merupakan sebuahSebagai indeksbahan hasilvalidasi perbandingan Sebagai bahan validasi penunjang penerbitan IEEC oleh oleh pemerintah atau RO, BKI memberikan layanan ERTIFIKASI DAN VERIFIKASI antara jumlah emisi CO2 yang di sebabkan oleh konsumpemerintah berupa penerbitan Statement of Verification (SoV) atau RO, BKI memberikan layanan berupa peuntuk EEDI dan EEOI,dan sertajarak pre-assesmen terhadap si bahan bakar per satuan kargo yang diangkut nerbitan Statement of Verification (SoV) untuk EEDI dan tempuh kapal. Dan konsep utama EEOI dapat dirumuskan EEOI, serta pre-assesmen SEEMP terhadap dan SEEMP. Dalam proses mengenai pemberlakuan EEDI, mempunyai pola efisiensi yang berbeda mengenai pemberlakuan SEEMP dan EEDI, mempunyai efisiensisebagai yang berbeda sebagai : penerbitan SoV, BKI akan review terhadap EEDI terdapat jenis sertifikat baru melakukan yang diterbitkan yaitu EEOIberikut dapat pola dirumuskan berikut: terdapat jenis Energy sertifikat baru yang diterbitkan yaitu EEOI dapat dirumuskan sebagai berikut: International Efficiency (IEEC). technical file maupun manualCertificate SEEMP serta verifikasi terhaInternational Energy Efficiency Certificate (IEEC). ∑ 𝐹𝐶 × 𝐶 IEEC statutoria yangdan akan dap merupakan indeks hasil sertifikat perhitungan untuk EEDI EEOI. ∑� 𝐹𝐶� × 𝐶��

IEEC merupakan yang akan diterbitkan satu sertifikat kali olehstatutoria pemerintah atau diterbitkan satu kali oleh pemerintah atau Recognized Organization (RO) untuk tiap tiap kapal Untuk mendukung assesment dan yang valid, Recognized Organization untuk tiapverifikasi tiap kapal dan valid selama kapal (RO) masih beroperasi atau Jika EEOI digunakan sebagai indeks monitoring kapal Sertifikat masih beroperasi atauGuidelines BKIvalid telahselama memublikasi guidelines terkait yaitu; JikaJika EEOI digunakan sebagai indeksindeks monitoring untuk be- dan digunakan sebagai monitoring sepanjang umur kapal. tersebut harus untukEEOI beberapa kali pelayaran misalnya monitoring sepanjang umur kapal. Sertifikat tersebut harus for Determination of Energy Efficiency Design berapa kali pelayaran misalnya monitoring tahunan pelauntuk beberapa kalisuatu pelayaran monitoring tersedia diatas kapal untuk keperluan inspeksi dan Index dan tahunan pelayaran kapal,misalnya maka EEOI dapat tersedia diatas2012) kapal untuk keperluan inspeksi dan Guidelines for Ship Energy Efficiency Management Plan yaran suatu pelayaran kapal, maka EEOI dapatmaka dirumuskan sebagai audit. tahunan kapal, EEOI dapat (IACS, dirumuskan sebagaisuatu berikut: audit. (IACS, 2012) dirumuskan sebagai berikut: (SEEMP). Kedua guidelines ini selanjutnya dipergunakan berikut : 𝐸𝐸𝑂𝐼 = � � �� 𝐸𝐸𝑂𝐼 = 𝑚�� × 𝐷 𝑚�� × 𝐷

∑� ∑� 𝐹𝐶� × 𝐶�� 𝐴𝑣𝑒𝑟𝑎𝑔𝑒 𝐸𝐸𝑂𝐼 = ∑� ∑� 𝐹𝐶� × 𝐶�� 𝐴𝑣𝑒𝑟𝑎𝑔𝑒 𝐸𝐸𝑂𝐼 = ∑� 𝑚��,� × 𝐷� ∑� 𝑚��,� × 𝐷�

Jurnal Teknik BKI Dimana: Desember 2014 Dimana: i Edisi 02 : -Jumlah pelayaran ij :: Jumlah pelayaran Tipe bahan bakar :: Teknik Tipe bahan bakar BKI 56 jCFj Jurnal Faktor konversi CO2 untuk jenis bahan bakar 2016 CO2 untuk jenis bahan bakar CFj Edisi : 03-Agustus Faktor konversi j D : jJarak pelayaran [nm]

Bagi kapal bangunan IEEC akanpenerbitan dikeluarkanSoV. Untuk sebagai salah satubaru, acuan untuk Bagi kapal bangunan baru, IEECbahwa akan EEDI dikeluarkan saatmemberikan survey initialassesmen dengan syarat sudah yangbahwa valid,EEDI BKI sudah juga menggusaat survey initial dengan telah syarat diverifikasi serta SEEMP tersedia diatas kapal. nakan regulasiSEEMP terbaru telah dari IMO maupun IACS diluar kedua diverifikasi tersedia diatas kapal. Sedangkan serta untuk kapal bangunan lama (exisiting Sedangkan untuk kapal bangunan lama (exisiting ship) sertifikat tersebut akan diberikan pada survey ship) sertifikat Air tersebut akan diberikan pada (IAPP) survey International Pollution Prevention International Air Pollution Prevention (IAPP) intermediate atau renewal yang pertama, dengan intermediate atau renewal yang pertama, syarat SEEMP tersedia diatas kapal. Untukdengan kasus syarat tersedia kapal. Untuk kasus tertentuSEEMP seperti jika suatudiatas kapal melakukan konversi tertentu suatu kapal melakukan mayor, seperti makajikaIEEC harus dibuat konversi ulang

terse audi

Bagi saat dive Seda ship Inter inter syar terte may men

Seba oleh beru untu


guidelines tersebut. Sedangkan secara teknis perhitungan BKI telah mengembangkan dan merilis perangkat lunak terbarunya yaitu GreenPADMA. Aplikasi ini diharapkan dapat membantu proses assesmen maupun approval yang valid guna penerbitan SoV.

4.

BKI-GreenPADMA

GreenPADMA merupakan software terbaru yang diluncurkan BKI pada tahun 2015 yang berupa perangkat yang digunakan untuk menghitung nilai EEDI dan EEOI pada suatu kapal. Software ini dikembangkan secara internal oleh Divisi Riset dan Pengembangan dan Divisi Statutoria dengan tujuan untuk memberikan pelayanan yang valid dan efisien terkait regulasi efisiensi energi dari IMO. Dalam pengembangannya, GreenPADMA diciptakan untuk sedapat mungkin mengakomodir semua ketentuan dan kriteria regulasi terkini. Adapun fitur - fitur yang ditawarkan telah divalidasi sesuai dengan update regulasi IMO maupun IACS. Fitur unggulan untuk EEDI misalnya antara lain; pengakomodiran 12 jenis kapal yang termasuk dalam kriteria regulasi, sistem propulsi konvensional maupun diesel electric, mesin dual fuel, perangkat tambahan untuk kapal LNG, penggunaan innovative technology seperti Air Lubrication System dan Waste Heat Recovery. Selain fitur yang reliable tersebut, GreenPADMA juga menawarkan tampilan hasil perhitungan yang user friendly berupa posisi indeks emisi CO2 terhadap batas emisi yang telah ditetapkan oleh IMO dalam bentuk plot grafik.

4.1.

Fitur Aplikasi EEDI

Secara umum, pada menu EEDI kalkulator, terdapat beberapa fitur utama seperti tipe kapal, jenis sistem permesinan dan penerapan innovative technology. Berikut merupakan penjabaran singkat terkait keunggulan fitur fitur utama tersebut. 4.1.1. Tipe kapal GreenPADMA dikembangkan seiring dengan perkembangan regulasi IMO yang terkini. Khususnya untuk tipe kapal, GreenPADMA sudah dapat mengakomodir 12 (dua belas) jenis kapal yang termasuk dalam regulasi EEDI, lihat Gambar 2. Dimana sebelumnya IMO hanya menentukan 8 (delapan) jenis kapal yang wajib EEDI. Kedua belas jenis kapal tersebut antara lain: (1) Bulk carrier, (2) Gas carrier, (3) LNG carrier, (4) Tanker, (5) Container ship, (6) General cargo ship, (7) Refrigerated cargo carrier, (8) Combination carrier, (9) Ro-ro cargo ship (vehicle carrier), (10) Ro-ro cargo ship, (11) Ro-ro passenger ship, (12) Cruise passenger ship.

Gambar 3. Dual fuel

Gambar 2 : Tipe Kapal Jurnal Teknik BKI Edisi 02- Desember 2014 Jurnal Teknik BKI Edisi 03-Agustus 2016

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Gambar 3 : Dual Fuel

Gambar 3. Dual fuel Gambar 4. Sistem Propulsi

Gambar 4 : Sistem Propulsi Untuk lebih melengkapi kedua jenis kapal tersebut diatas, GreenPADMA juga dikembangkan dengan memperhatikan kriteria tambahan untuk beberapa sub-type kapal. Beberapa contoh sub-type kapal yang sudah terkamodir dalam perangkat ini antara lain : a. Kapal dengan atau tanpa voluntary structural enhancements (VSE). b. Kapal General Cargo akan dibedakan menjadi; General Cargo dengan dan tanpa ramp, crane, dan side loader. c. Kapal Tanker akan dibedakan menjadi Oil Tanker dan Chemical Tanker, atau menggunakan CSR atau tidak. d. dan lain sebagainya. Jurnal Teknik BKI Edisi 02 - Desember 2014

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Jurnal4.1.3. TeknikInnovative BKI Technology Edisi 03-Agustus 2016

4.1.2. Sistem Permesinan Dalam sistem permesinan dan propulsi, GreenPADMA telah mengakomodir kriteria tambahan seperti: penggunaan shaft generator dan motor, kapal dengan dual fuel engine (lihat gambar 3), kapal LNG carrier dengan sistem propulsi diesel electric (lihat gambar 4) serta kriteria tambahan untuk kapal LNG carrier yang menggunakan reliquefaction system atau compressor. Secara lebih detail lagi terdapat opsi tambahan lagi pada sistem propulsi yang menggunakan shaft generator yaitu ada atau tidaknya pembatasan power. Selain itu, pada

Gambar 5. LNG Carrier

Sejalan dengan konsep utama regulasi EEDI dan SEEMP, dimana sebuah kapal harus dibangun dan dioperasikan seefisien mungkin serta diharapkan untuk dilengkapi dengan inovasi teknologi yang dapat

Technical Journal of Classification and Independent Assurance Gambar 4. Sistem Propulsi

Gambar 5. LNG Carrier

Gambar 5 : LNG Carrier 4.1.3. Innovative Technology

gambar 5 mengilustrasikan terdapat juga opsi tambahan dikator dari SEEMP, maka dapat diartikan bahwa parameSejalan yang denganmenggunakan konsep utama regulasi EEDI dan SEEMP, dimana sebuah kapaldalam harus perhitungan dibangun dan merupakan papada kapal LNG carrier reliquefaction ter yang dimasukkan dioperasikan seefisien mungkin serta diharapkan untuk dilengkapi dengan inovasi teknologi yang dapat system atau compressor, yaitu : operasional kapal. Sesuai regulasi maka menghemat konsumsi bahan bakar. Maka GreenPADMArameter juga dilengkapi dengan menu tambahan yaitudengan menu innovative technology.re-liquefaction Beberapa contoh system. teknologi inovatif yang sudah terdapat dalam aplikasi adalah; Air a. Untuk kapal yang mempunyai GreenPADMA menampilkan parameter-peremeter berikut b. Untuk kapal dengan diesel atau diesel electric dileng- dalam aplikasinya: kapi dengan kompresor yang digunakan untuk a. jumlah pelayaran. menyuplai gas bertekanan tinggi yang berasal dari b. tipe bahan bakar. boil-off gas (BOG). Tipe ini umumnya terdapat pada c. faktor konversi CO2 untuk jenis bahan bakar. kapal dengan mesin 2 tak. d. jarak pelayaran [nm]. c. Untuk kapal dengan diesel atau diesel electric e. Konsumsi bahan bakar untuk masing masing jenis badilengkapi dengan kompresor yang digunakan untuk han bakar pada pelayaran tertentu. menyuplai gas bertekanan rendah yang berasal dari f. Kargo yang diangkut kapal [tonnes] atau TEU atau boil-off gas (BOG). Tipe ini umumnya terdapat pada n penumpang. kapal dengan mesin 4 tak. g. Karakteristik muatan kapal saat berlayar seperti : ballast, distribusi beban muatan, dan lain sebagainya. 4.1.3. Innovative Technology 4.3. Output Aplikasi Sejalan dengan konsep utama regulasi EEDI dan SEEMP, dimana sebuah kapal harus dibangun dan dioperasikan Dalam regulasi yang berlaku, nilai EEDI harus dihitung seefisien mungkin serta diharapkan untuk dilengkapi sesuai dengan formulasi yang disebutkan dalam bagian dengan inovasi teknologi yang dapat menghemat kon- 2 diatas. Nilai EEDI yang dihitung berdasarkan technical sumsi bahan bakar. Maka GreenPADMA juga dileng- file yang diverifikasi. Dan selanjutnya, untuk mengetakapi dengan menu tambahan yaitu menu innovative hui apakah nilai tersebut sudah memenuhi batas kriteria technology. Beberapa contoh teknologi inovatif yang su- yang ditentukan, maka nilai tersebut harus dibandingkan dah terdapat dalam aplikasi adalah; Air Lubrication System, dengan reference line yang telah ditentukan oleh IMO. Waste Heat Recovery, dan lain sebagainya. Penerapan te- Batasan nilai EEDI yang ditentukan oleh IMO didapatkan knologi inovasi tersebut dihitung berdasarkan guidelines dari formulasi sebagai berikut: yang diterbitkan IMO atau gudelines yang setara. Required EEDI = a · b-c 4.2. Fitur Aplikasi EEOI Batasan nilai EEDI tersebut, dihitung berdasarkan masing Seperti dijelaskan sebelumnya bahwa EEOI merupakan in- masing jenis kapal dengan koefisien a dan c dengan DWT Jurnal Teknik BKI Edisi 02- Desember 2014 Jurnal Teknik BKI Edisi 03-Agustus 2016

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Gambar 6. Reference Line

Gambar 6 : Reference Line

Sedangkan untuk output EEOI akan ditunjukkan dengan grafik yang menggambarkan total emisi CO2 pada pelayaran yang dilakukan. Grafik akan dapat digenerate untuk per perjalanan kapal atau dalam kurun waktu tertentu.

nya, b. Selain itu, batasan nilai EEDI yang dipersyaratkan 5. KESIMPULAN juga akan semakin ketat dari tahun ke tahun. Selanjutnya, Regulasi terkait energi efisiensi merupakan regulasi baru yang diberlakukan hasil perhitungan batasan atau regulasi baik daridari IMO maupun IACS. Beberapa oleh IMOgrafik dan dapat dipastikan akan semakindan ketat interpolasi contoh fitur yang ditawarkan yaitu; dapat di masa yang akan datang. Penerapan regulasi reference line tersebut ditampilkan sebagai plot akhir permengakomodir 12 jenis kapal sesuai regulasi IMO tersebut harus didukung oleh semua pihak terutama terkini, mengakomodir jenis mesin dual fuel dan pemerintah, RO, maupun badan klasifikasi. Dalam hitungan indeks EEDI seperti ditunjukkan dalam gambar 6 diesel electric, mengakomodir penerapan inovasi perannya, badan klasifikasi diharapkan dapat technology pada kapal, dan fitur fitur lainnya. senantiasa memperbarui pelayanannya terkait dibawah ini. Dalam tampilannya, nilai EEDI yang dihitung Dengan adanya pelayanan baru tersebut, maka BKI perkembangan regulasi dunia. Untuk mencapai hal menunjukkan komitmen sebagai badan klasifikasi tersebut, BKI telah memberikan pelayanan untuk kapal akan berupa titik (dot) yang selanjutnya yang memperhatikan kebutuhan pelanggan akan terbarunya suatu yaitu penerbitan Statement of perkembangan regulasi terbaru serta dapat Verification (SoV) untuk EEDI dan SEEMP yang diplot pada grafik tersebut untuk mengetahui apakah mamemberikan pelayanan yang valid dan efisien. termasuk didalamnya EEOI. Sebagai penunjang secara teknis, BKI juga telah mengembangkan sih dalam kriteria yang dapat atau tidak. DAFTAR PUSTAKA perangkat yang dapat memberikan assesmen yang diterima valid dan efisien kepada parameter kuantitatif pada Sedangkan untuk output EEOI akan ditunjukkan dengan38 IACS. (2013). IACS Procedure Requirement regulasi tersebut. Perangkat ini berupa software Procedure for calculation and verification of kalkulator EEDI dan EEOI bernama GreenPADMA. grafik yang menggambarkan total emisi CODesign pada pelathe Energy Efficiency Index (EEDI) 2 IACS. (2012). IACS MPC 102 Surveys and GreenPADMA merupakan perangkat penghitung yaran yang dilakukan. Grafik akan dapat di-generate untuk certification relating to the Ship Energy yang dilengkapi dengan fitur-fitur terkini yang Efficiency Management Plan (SEEMP) . selalu diperbarui sesuai dengan perkembangan per perjalanan kapal atau dalam kurun waktu tertentu.

GreenPADMA merupakan perangkat penghitung yang dilengkapi dengan fitur-fitur terkini yang selalu diperbarui sesuai dengan perkembangan regulasi baik dari IMO maupun IACS. Beberapa contoh fitur yang ditawarkan yaitu; dapat mengakomodir 12 jenis kapal sesuai resgulasi IMO terkini, mengakomodir jenis mesin dual fuel dan diesel electric, mengakomodir penerapan inovasi technology pada kapal, dan fitur fitur lainnya. Dengan adanya pelayanan baru tersebut, maka BKI menunjukkan komitmen sebagai badan klasifikasi yang memperhatikan kebutuhan pelanggan akan perkembangan regulasi terbaru serta dapat memberikan pelayanan yang valid dan efisien.

DAFTAR PUSTAKA

Regulasi terkait energi efisiensi merupakan regulasi baru yang diberlakukan oleh IMO dan dapat dipastikan akan semakin ketat di masa yang akan datang. Penerapan regulasi tersebut harus didukung oleh semua pihak terutama pemerintah, RO, maupun badan klasifikasi. Dalam perannya, badan klasifikasi diharapkan dapat senantiasa memperbarui pelayanannya terkait perkembangan regulasi dunia. Untuk mencapai hal tersebut, BKI telah memberikan pelayanan terbarunya yaitu penerbitan Statement of Verification (SoV) untuk EEDI dan SEEMP yang termasuk didalamnya EEOI. Sebagai penunjang secara teknis, BKI juga telah mengembangkan perangkat yang dapat memberikan assesmen yang valid dan efisien kepada parameter kuantitatif pada regulasi tersebut. Perangkat ini berupa software kalkulator EEDI dan EEOI bernama GreenPADMA.

IACS. (2013). IACS Procedure Requirement 38 Procedure for calculation and verification of the Energy Efficiency Design Index (EEDI) IACS. (2012). IACS MPC 102 Surveys and certification relating to the Ship Energy Efficiency Management Plan (SEEMP) . London: IACS. IMO. (2012). Resolusi MEPC.212 (63) Guidelines on the method of calculation of the attained Energy Efficiency Design Index (EEDI) for new ships. London: IMO. IMO. (2012). Resolusi MEPC.213 (63) Guidelines for the development of a Ship Energy Efficiency Management Plan (SEEMP). London: IMO.IMO. (2009). Resolusi MEPC.1/Circ.684 Guidelines For Voluntary Use Of The Ship Energy Efficiency Operational Indicator (EEOI). London: IMO. IMO. (2014). Resolusi MEPC.245(66) Guidelines on The Method of Calculation of The Attained Energy Efficiency Design Index (EEDI) for New Ships. London: IMO. IMO. (2013). Resolusi MEPC. 231(65) Guidelines for calculation of reference lines for use with the Energy Efficiency Design Index (EEDI). London: IMO. IMO. (2013). Resolusi MEPC.233(65) Guidelines for calculation of reference lines for use with the Energy Efficiency Design Index (EEDI) for cruise passenger ships having non-conventional propulsion. London: IMO. IPCC. (2007). Contribution of Working Group III to the Fourth Assessment Report of the to the Fourth Assessment Report of the. New York: Cambridge University Press.

Tribuana Galaxy, adalah surveyor di Divisi Statutoria PT. Biro Klasifikasi Indonesia (Persero). Penulis menyeleJurnal Teknik BKI saikan pendidikan Sarjana Teknik pada tahun 2008 di JuEdisi 02 - Desember 2014 rusan Teknik Sistem Perkapalan, FTK, Institut Teknologi

Sepuluh Nopember (ITS) Surabaya dan menyelesaikan pendidikan Master pada tahun 2012 di Fakultas Marine Technology, Norwegian University of Science and Technology (NTNU) Norwegia.

5.

60

Kesimpulan


ON THE USE OF THE LIFTING LINE THEORY FOR OPTIMIZING THE PROPELLER PERFORMANCE OF SHIP

Muhdar Tasrief, Faisal Mahmuddin

Abstract Propeller is one of the most important and crucial part of a ship. Knowing and understanding the characteristics of a propeller may enable us to optimize its performance. Performance of a propeller in this paper is measured from its efficiency. Choosing the blade number of propeller correctly and operating it into a suitable rotation shall optimize its performance. Hence, in the present study the lifting line theory is employed to compute such performance through the Propeller Vortex Lattice (PVL) program. It is understood from this study that a propeller with less number of blades and small in diameter is recommended to be operated at middle to higher rotation and vice versa in order to acquire the highest efficiency. The effect of propeller hub increases the strength of circulation distribution, especially around the propeller hub radius. Keywords : propeller performance; lifting line theory; propeller vortex lattice

1.

Introduction

A

lthough the regulation of Energy Efficiency Design Index (EEDI) has been imposed for more than two years, but many researcher are still doing and trying to search an effective and efficient technique to comply with the required EEDI of that regulation. It should be noted that EEDI is an index quantifying the amount of carbon dioxide (CO2) emitted from a ship in relation to the goods transported and it is a mandatory for the new ships with 400 gross tonnages and above. The EEDI of such ships should be less than the required EEDI stipulated by the International Maritime Organization (IMO). Therefore the ships shall be designed and operated optimally in order to acquire less EEDI. In fact, the EEDI of a ship can be reduced from several point of views, for instance from the view of speed reduction, hull optimization, advanced technology devices, etc. Optimizing the propeller performance may also save fuel of a ship in operation and hence reducing the EEDI. Propeller is one of the most important parts of a ship. Without a propeller, a ship will not be able to advance with its forward speed. Knowing the characteristics of a propeller shall allow us to understand and optimize its performance. There are a lot of benefits that can be obtained by understanding the propeller performance. For example, it

Jurnal Teknik BKI

PROPULSION

enables us to decide the number of propeller blade correctly. Another thing is that we may be able to operate the propeller at its optimum rotation and thus optimizing its performance, saving more fuel which lead to reduction of CO2 pollution from ship, etc. Hence, operating the propeller at its optimum rotation may help us to comply with the EEDI regulation as mentioned before. There are two methods commonly used to examine the performance of propeller. The first method is the conventional propeller series method based on diagrams obtained from open water experimental data. The other one is the mathematical method based on circulation theory, such as lifting line theory, vortex lattice method, boundary element method (BEM), etc. The conventional method is easy and convenient to use since the propeller performance can be obtained through diagrams as long as all necessary data such as ship speed (Vs), diameter (D) or radius (R) of propeller and its rotation (n), and number of propeller blade (Z), etc. are known. Nevertheless, it may lead to a problem when certain necessary data, for instance, propeller rotation is not available. Another thing which may be considered as a drawback of the first method is that the accuracy of the obtained propeller performance highly depends on the precision in reading the diagrams. Such kinds of deficiency shall not be encountered in another available method.

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PROPULSION precision in reading the diagrams. Such kinds of PROPULSION deficiency shall not be encountered in another With the assumption available method.that the optimum propeller rotation is unknown, the conventional method may not be used, hence thethe mathematical should be adopted inWith assumptionmethod that the optimum propeller stead. In this study, therefore, the mathematical method rotation is unknown, the conventional method may particularly liftinghence line theory the principlesmethod of vornot be the used, the and mathematical tex should lattice solution are utilized together in the propeller be adopted instead. In this study, therefore, vortex program developed by Kerwin (2001) which the lattice mathematical method particularly the lifting andthe thepropeller principles of vortex are line used theory to analyse performance of lattice a ship. solution are utilized together the apropeller Vortex lattice method is generally robustinwhere lot spaclattice program developed by Kerwin ing vortex algorithms do converge to the correct answer (Kerwin, (2001) which are used to analyse the propeller 1986). In the lifting line theory, each blade of the propeller ship. surface Vortex with lattice method is canperformance be consideredof as aa lifting some distribugenerally robust where a lot spacing algorithms do tion of vortex sheet strength. It is then considered for the converge tovanishing the correct answer (Kerwin, 1986).is In limiting case of chord length. The objective to the lifting line theory, each blade of the propeller calculate the circulation distribution along propeller blade can be considered as a lifting surface with some radius and hence computing force of a propeller by the distribution of vortex sheet strength. It is then vortex lattice solution. Obtaining the force may allow us to considered for the limiting case of vanishing chord get the propeller efficiency and understand in which rotalength. The objective is to calculate the circulation tion a propeller will acquire its highest efficiency.

distribution along propeller blade radius and hence computing force of a propeller by the vortex lattice Obtaining the force may allow us to get 2. solution. Theory Of Computation the propeller efficiency and understand in which rotation a propeller will acquire its the highest It has been mentioned in the former section that lifting efficiency. line theory and the principle of vortex lattice solution are

adopted in the propeller vortex lattice program in order 2. Theory Of Computation to obtain the distribution of circulations on each propeller blades sections. These results will then be used to comIt has been mentioned in the former section that pute the forces in the axial and tangential directions. By the lifting line theory and the principle of vortex integrating these forces over the radius and summing up lattice solution are adopted in the propeller vortex over the number of blades as they are identical, the total lattice program in order to obtain the distribution propeller thrust and torque may be obtained. The followof circulations on each propeller blades sections. ing subsection will describe these problems in sufficiently These results will then be used to compute the detail. forces in the axial and tangential directions. By

integrating these forces over the radius and

2.1. summing Coordinate System Notation up over theand number of blades as they are

identical, the total propeller thrust and torque may

A right-handed coordinate is adopted to definewill the be obtained. The system following subsection describe these problems in sufficiently detail. propeller coordinate system and notation, with the x-axis coincident with the axis of propeller rotation and y-axis 2.1 Coordinate and Notation positive upward. TheSystem z-axis completes the right-handed coordinate system as shown in the following Figure 1.

A right-handed coordinate system is adopted to definein Figure the propeller coordinate and As shown 1, the propeller is rotatingsystem with angular notation, with the x-axis coincident with the axis velocity (ω) in a clokwise direction when looking downof propeller and y-axis stream. The axial rotation inflow velocity ( VA ) ispositive coming upward. from the The z-axis completes the right-handed coordinate negative x-axis, where the origin of the coordinate is in the plane of propeller as a reference point for all axial dimensions of the surface of a propeller blade. Jurnal Teknik BKI Edisi 02 - Desember 2014

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system as shown in the following Figure 1.

Figure 1 : Propeller Coordinate System and Notation

Figure 1. Propeller Coordinate System and Notation

Since a propeller has Z number of identical blades with As shown in Figure the one propeller is considered rotating with maximum radius R, thus1,only blade is first (𝜔 ) in a clokwise velocity direction forangular computing the distribution of circulation which iswhen called downstream. Thecolor axial inflow1. This velocity aslooking a key blade given as green in Figure blade (𝑉�the ) isothers coming x-axis, where the and are from placedthe onnegative a hub which is attached to a origin of the coordinate is in the plane of propeller shaft. The hub and shaft may be considered as an axisymas a body reference point for all axial of ther . metric and usually idealized as adimensions cylinder of radius h

surface of a propeller blade.

2.2.

Vortex Lattice Lifting Surface

Since a propeller has 𝑍 number of identical blades maximum radiuseach 𝑅, thus one blade In with the lifting line theory, bladeonly of propeller mayisbe considered first for computing the distribution of considered as a lifting surface with some of bound and circulation which is called as a key blade given as free vortex sheet strength distributed along the lifting surgreen color in Figure 1. This blade and the others face. Bound vortex is the portion of the vortex lying along are placed on a hub which is attached to a shaft. the span and the free vortex or so-called the trailing vorThe hub and shaft may be considered as an tex extending downstream indefinitely (Flood, 2009). The axisymmetric body and usually idealized as a limiting case of vanishing chord length is then considered. cylinder of radius 𝑟� . Therefore the bound vortex reduces to a single concentrated vortex on each Lifting blade with strength Γ( r ) as for a 2.2 Vortex Lattice Surface planar foil. Beacuse the propeller blades are identical, they will same circulation Inhave the the lifting line theory, distribution each blade inofcircumferenpropeller tially uniform flow and thus blade can bewith chosen and may be considered as a one lifting surface some designated as a key blade. of bound and free vortex sheet strength distributed

along the lifting surface. Bound vortex is the

portion span and theof The span ofofa the key vortex blade islying then along dividedthe into M number free extending vortex or the trailing vortex panels fromso-called the hub radius, r = rh to the maxextending downstream (Flood, imum radius of propeller r indefinitely = R. Its chord is also2009). divided into N number of panels. A specified control point, rc will be put in the middle of each panel of a key blade where

willof be putbe control point,𝑟radius put ininthe AAspecified point, 𝐽� = 𝑉� (7) 𝑛𝐷 �𝑟��will withthe 𝑟specified =A𝑟�specified tocontrol the maximum 𝑟the = in 𝑅. 𝑛𝐷 𝑛𝐷 ++𝑦𝑦��−as 𝑦𝑦� �1 will put control point, 𝑟be −11 �1 given � propeller 𝑛𝐷 =++ same circulation distribution circumferentially uniform flow thus one blade can be chosen uniform flowA and thus one blade canblade be chosen �� 𝑦𝑦�� exp middle of each panel ofainaapoint, key blade where the𝑈in 𝑈==the �1 �� exp��1 ��1++𝑦𝑦��−𝐽−��1 be put specified control 𝑟number middle of each panel of key blade where the middle ofand each panel of key where � will �� 𝑦 � − 1 𝑛𝐷 Its chord is of also divided into 𝑁 of the panels. + 𝑦 �1 middle each panel of a key blade where the 𝑉 𝑦�1 � ++𝑦𝑦 𝑦�1 (7) � ��1 + 𝑦 � −��1 + 𝑦 ��(6) ��−−11 � exp uniform flow and thus onepanel be chosen (6)of propeller and designated as aakey blade. 𝑈the =where � and designated as key blade. induced velocity field inaxial axial andtangential tangential middle of each of𝑟can aand key blade � = induced velocity field in axial and tangential induced velocity field inblade 𝑛=−= =1 �11 is is𝐽��the the number number � 𝑟�𝑟�𝑦�1 +where 𝑉𝑉 where is the number propeller where 𝑛𝑦�𝑛 ofof propeller be put where in 𝑦the A specified control point, induced velocity field in axial and tangential �� number ��𝑛 = � will is the of propeller 𝑛𝐷 � �� (6) = ; 𝑦 = ; tan 𝛽 = anddirections designated as a key blade. 𝑦 = ; 𝑦 = ; tan 𝛽 = directions will be computed. These velocities are �� induced velocity field in and tangential 𝜋𝑟 directions willeach computed. velocities arethe 𝑟are will bebe computed. velocities are 𝜋𝑟 𝑛𝛽second. is the++be number ofthat propeller 1= �� It It 𝑉𝑉 tan revolutions per second. It should be notedhere here that 𝑟�tan tan𝑟𝛽�𝛽 where tan 𝛽 � directions will be computed. These velocities middle of panel of These aThese keyaxial blade where � 𝑉 revolutions per should noted here that revolutions per second. should noted �be �� Independent 𝑦 = ; 𝑦 = ; tan 𝛽 = Technical Journal of Classification and Assurance The of a key blade is then divided into 𝑀 𝐽 revolutions per second. It should be noted here that actually induced by each set of horseshoe vortex The span span of a key blade is then divided into 𝑀 𝐽 � � �𝜋𝑟 directions will be computed. These velocities are actually induced by each set of horseshoe vortex actually induced by each set of horseshoe vortex � 𝑟 tan 𝛽 tan 𝛽 the cosine spacing described inDannecker Dannecker (1997) actually inducedfield by each set ofand horseshoe vortex induced velocity in divided axial tangential � cosine + 𝑉� be revolutions per second. should noted here that the cosine spacing described in Dannecker (1997) the spacing described inIt (1997) where 𝑛 = is the number of propeller Theelements span of a key blade is then into 𝑀 𝐽 number of panels extending from the hub radius, the cosine spacing described in Dannecker (1997) number of panels extending from the hub radius, elements consisting of a bound vortex segment of � actually induced by each set of horseshoe vortex inin of Eq. (6) represents advance coefficient �� the 𝐽��are Eq. (6) represents theadopted advance coefficient elements consisting bound vortex segment consisting ofofcomputed. a abound vortex segment of𝐽of andKerwin Kerwin (2011) is forthe the vortices and(1997) directions will be These velocities elements consisting of a bound vortex segment the cosine spacing described in Dannecker and Kerwin (2011) is adopted for the vortices and and (2011) is adopted for vortices and number ofelements panels extending from hub radius, revolutions per second. It adopted should be noted here thatand and Kerwin (2011) is for the vortices 𝑟𝑟= totothe maximum radius of propeller 𝑟𝑟of = 𝑅. strength and two free vortex lines ofstrength strength =𝑟𝑟strength the radius ofof propeller = 𝑅. consisting a the bound vortex segment 𝐽� inof Eq. (6)points represents theequations advance coefficient given as ��strength �and given as ΓΓ� and two free vortex of strength Γmaximum free vortex lines � control inabove above to compute the and actually induced by each set oflines horseshoe strength Γtwo and two free vortex lines ofvortex strength and Kerwin (2011) is adopted for the vortices control points in above equations to compute the control points in equations toDannecker compute the � into the cosine spacing described in (1997) =±Γ 𝑟±Γ the maximum radius of propeller 𝑟 = 𝑅. control points in above equations to compute the Its is also divided 𝑁 number of panels. ±Γ Its𝑟chord chord is also divided into 𝑁 number of panels. . Hence the total induced velocity at 𝑟 can be 𝑉 𝑉 strength Γ and two free vortex lines of strength given as ��to (7) (7) � � . Hence the total induced velocity at 𝑟 can be .elements Hence the total induced velocity at 𝑟 can be � � which � the total � ±Γ . Hence � at 𝑟 can � segment vortex lattice grid, can be given as: consisting of a bound vortex of induced velocity be control points in above equations to compute vortex lattice grid, which canbebegiven given as:vortices vortex which 𝐽𝐽��grid, == � individed �as chord is±Γ also into 𝑁tangential number of andlattice Kerwin (2011) iscan adopted forbeas: the vortex lattice grid, which can given as: and the computed axial and tangential directions will be ininpanels. the AAIts specified control point, 𝑟𝑟�total 𝑉 will be put put the atas specified control point, (7) . Hence the induced velocity 𝑟 can be computed in axial and directions as computed in axial and tangential directions � � 𝑛𝐷 � � 𝑛𝐷 ((2 )]given (8) 𝑟(��𝑚 𝑚 =𝑟�𝑟𝑟�+ + ℎ1[[1 1 − cos 2((𝑚 𝑚−− −1)1 1)))] strength Γ�in and free vortex lines ofdirections strength 𝑟as computed in two axial and tangential grid, be ((control ))vortex )] )= [ℎ �)𝐽+ (8) 𝑚 − 𝛿𝛿− ℎ − cos �𝑟 �lattice the induced velocity field axial and [(12(which (can )compute points in+ above equations to1(8) will putdirections inthe the A specified control point, 𝑟� tangential 𝑟= == 𝑟�𝑛𝐷 ℎcos −𝑚 cos 2 (𝛿𝑚 𝛿 )]as: (8)the follow: middle of panel of key blade where middle of each each panel of aaaxial key bladebe where the computed in and tangential directions as � (𝑚 follow: follow: ±Γ�follow: . Hence the total induced velocity at 𝑟 can be ( ) [ ( ( ) 𝑟 𝑚 = 𝑟 + ℎ 1 − cos 2 𝑚 − 1 𝛿 )] (8) ( ) [ ( ) ] � (9) � 𝑟 𝑛 = 𝑟 + ℎ 1 − cos 2𝑛 − 1 𝛿 � � � � (= )= (−2𝑛cos ]propeller )𝑛== (2𝑛 )12𝑛 � (9) �)+ 𝑟𝑛+ 1−−cos cos −1of 𝑟�𝑟(𝑛��𝑛 1the − 𝛿)]𝛿propeller which can be given as: middle velocity of follow: each field panel of aaxial key blade where the (1) where in and tangential induced velocity field in� axial and tangential � will be induced computed. These velocities are actually induced [1 (of ](9) (9) (1) (1) � tangential isisℎ 𝑟�𝑟�(lattice =[ℎthe 𝑟[grid, ℎnumber − 1)𝛿 where 𝑛vortex � + number computed in axial and directions as (1) �� ∗ � �� ( ) [ ( ) ] � 𝑛 𝑟= 1cos − cos 1𝛿 )] 𝛿 (8) (9) ∗𝑢∗� �𝑟 (𝑚 [ 1ℎ−number (2 (𝑚2𝑛 ) tangential = ℎ+ −−1)propeller induced velocity field inΓ� axial and � will be These velocities are 𝑛computed. =� ΓThese 𝑢 𝑛, 𝑚 directions be(computed. velocities are (1) � ))�𝑟 )𝑛 � where 𝑟�𝑛per =𝑟�)second. is +𝑟�Itthe of ��== ��(��𝑛,((Γ𝑛, 𝑚 𝑢will �∗vortex 𝑢�� 𝑚 by eachdirections set of horseshoe consisting � �𝑟 �𝑢�𝑟 � (��𝑛(𝑢 �𝑢 (𝑛� )�elements should be noted here that revolutions per second. It should be noted here that follow: =Γ� 𝑢 �)�)(𝑛, 𝑚) of arevolutions �� ∗ (�� − 1)𝛿 ] directions will by be computed. These velocities actually induced set ofof� horseshoe actually induced by each horseshoe vortex )set �� (�� (�� )��))ℎ[1 − cos�(2𝑛 𝑢�each �𝑟 𝑛�� = Γ� 𝑢 � � (𝑛,vortex 𝑚) are (1)the � (𝑛per )= � (9) the 𝑟spacing = 𝑟described �� + �( � � revolutions second. It should be noted here that (�� ) cosine in Dannecker (1997) � where ℎ and 𝛿 = . By combining the cosine spacing described in Dannecker (1997) �� bound vortex segment of strength Γ_m and two free vortex where and Bycombining combining whereℎwhere ℎ== �ℎ��=and and𝛿 𝛿==�� . =By combining the the axial where .𝛿By the �� actuallyconsisting induced set �� of horseshoe vortex elements of aeach bound vortex segment of elements consisting of a bound vortex segment of (�� ) and � . By combining the ∗ by �� . By � induced theKerwin cosine spacing described in the Dannecker (1997) )the and (2011) is adopted for vortices and � Γ�induced and Kerwin (2011) adopted for the vortices and 𝑢Hence � �=� 𝑢�� (𝑛, 𝑚)velocity where ℎis = and 𝛿velocities = combining �total � �𝑟� (𝑛of axial and tangential velocities with the the lines of strength strength ±Γ . at and tangential induced velocities with the effective inflow axial and tangential induced velocities with the axial and tangential induced with the (2) elements consisting a bound vortex segment of Γ and two free vortex lines of strength �� strength Γ�� and two free vortex�lines of strength (2)(2) control m axial and tangential induced velocities with the (2) (�� )velocities and Kerwin (2011) is adopted for the vortices and points in above equations to compute the � control points in above equations to compute the ∗ �� ) ( and effective inflow in axial 𝑉 � ∗and ∗the axial and tangential induced velocities with the ) ( ) ( ( ) ( ) � � and effective inflow velocities in axial 𝑉 and effective inflow velocities in axial 𝑉 𝑢 �𝑟 𝑛 � = Γ 𝑢 � 𝑛, 𝑚 where ℎ = and 𝛿 = . By combining the strength Γ two free vortex lines of strength . Hence total induced velocity at 𝑟 can be (2) ±Γ . Hence the total induced velocity at 𝑟 can be ( ) ( ) � ( ) ( ) � � � ∗ � � � � r_c can ±Γ be computed in axial and tangential directions as 𝑛� �𝑟 �== Γ�Γ� 𝑢��𝑢�𝑟 𝑢��𝑢��𝑛,𝑛, 𝑚𝑚 velocities in inaxial (Vcan ) and tangential ) directions (𝑉� ) and and �� effective velocities in (Vaxial � 𝑚) � �𝑟 � �𝑛𝑢 �� inflow control points above equations to compute A T the � (�𝑛, vortex lattice grid, which be given as: vortex lattice grid, which can beand given as: �∗ � (𝑛 )� = � Γ� 𝑢 tangential 𝑉 directions andthe the rotational speed (𝑉� ) and effective velocities in rotational axial )) directions (𝑉((�𝑉 )tangential � tangential and the rotational speed tangential directions rotational speed (�� )� = (𝑛,𝑟�𝑚can ) as ±Γ�. Hence the total velocity inin axial �� 𝑟 𝑛tangential Γdirections 𝑢��at computed axial𝑢 and tangential directions asbe (2) (vortex � � � (inflow )can axial and induced velocities with the �� and �induced � tangential 𝑉 directions and the speedof an follow: computed the rotational speed of propeller (ωr), the resultant � [ ( ( ) )] lattice grid, which be given as: (8) [ ( ( ) )] 𝑟�𝑟� (𝑚 == 𝑟𝑟�propeller + ℎ 1 − cos 2 𝑚 − 1 𝛿 (8) 𝑚))of + ℎ 1 − cos 2 𝑚 − 1 𝛿 �� ( ) 𝜔𝑟 , the resultant of an inflow ( ) tangential 𝑉 directions and the rotational speed ( ) ( ) propeller 𝜔𝑟, �,the the resultant inflow ofofpropeller 𝜔𝑟 resultant ofofaxial ananof inflow computed in axial and tangential directions as follow: follow: ∗ ) and (𝑉an �� ( ) effective inflow velocities in of propeller 𝜔𝑟 , the resultant inflow ( ) ( ) � � ( ) [ ( ( ) )] 𝑢 �𝑟 𝑛 � = Γ 𝑢 � 𝑛, 𝑚 (8) 𝑟 𝑚 = 𝑟 + ℎ 1 − cos 2 𝑚 − 1 𝛿 �and ��𝑢 � �horseshoe influence � � inflow velocity can be computed by the following equation ( ) [ ( ) ] (9) ( ) [ ( ) ] velocity can be computed by the following 𝑟 𝑛 = 𝑟 + ℎ 1 − cos 2𝑛 − 1 𝛿 (9) 𝑟 𝑛 = 𝑟 + ℎ 1 − cos 2𝑛 − 1 𝛿 ( ) where 𝑢 � � denote the of propeller 𝜔𝑟 , the resultant of an inflow � � velocity can be computed by the following velocity can be computed by the following � � follow: (1) where𝑢�where � ��and and denote thehorseshoe horseshoe influence where the (1)influence (𝑉�can ) directions ��denote �𝑢 tangential and the rotational speed velocity be computed by the following 𝑢�𝑢��𝑢��and 𝑢�� denote the horseshoe influence ( ) [ ( ) ] (9) ∗∗ ((where 𝑟 𝑛 = 𝑟 + ℎ 1 − cos 2𝑛 − 1 𝛿 equation velocity can be computed by the following function of axial and tangential velocities, � � equation equation ) ( ) 𝑢 � and 𝑢 � denote the horseshoe influence (1) ) ( ) � 𝑢 �𝑟 𝑛 � = Γ 𝑢 � 𝑛, 𝑚 of � tangential velocities, function axial tangential velocities, 𝑢function 𝑛 �of= Γ�� 𝑢�and �axial � 𝑛, 𝑚 �� 𝑟 �� function � �and propeller (𝜔𝑟), the resultant of an inflow of axial and tangential velocities, of equation ∗ � � (10) (10) repectively. For finite bladed propeller,these these equation � � (10) (𝑛)𝑢��For ) bladed ∗ � (�� computed function axial and tangential velocities, � (�� 𝑢where = Γ� 𝑢��a(bladed 𝑛, 𝑚 �+ �𝜔𝑟� + 𝑉 ( 𝑟by repectively. For finite bladed propeller, these repectively. aofaa𝑢�finite propeller, � �� )()𝑟)can �� ∗𝑉 ∗∗velocity � �𝑟�repectively. )� )��following ∗∗� �𝑉 = + 𝑢(𝛿 + 𝑢(the be � � and denote the horseshoe influence For finite propeller, these )and (()� )� )) + )� (��𝑟()𝑟+ �𝑉 �𝜔𝑟 �𝑉 �𝜔𝑟 𝑉 = + 𝑟𝑟= 𝑉 𝑟𝑟the 𝑉 = 𝑟=()𝑟and + 𝑢∗�𝑢 + ++ 𝑉combining 𝑢𝑉�∗𝑢 𝑟∗�𝑟(()� ∗ ( )�� (10) where ℎ = = . By ∗+ � � where ℎ = 𝛿 . By combining the �𝑟𝑟 �∗(� � � � ( ) ( )� ( ) �𝑉 �𝜔𝑟 𝑉 + 𝑢 𝑟 + + + 𝑢 � functions canbebe be approximated asbladed propeller, these equation �� 𝑟 � (10) �� (�� ) � �� repectively. For aand finite functions can approximated as functions can approximated astangential �� (𝑟)𝛿+= 𝑉 ∗ =��𝑉 𝑢∗� (𝑟)� + �𝜔𝑟 + 𝑉� ( 𝑟) +the 𝑢�∗ (𝑟 )� functions be approximated as function of axial velocities, where ℎ tangential = and . By combining � �� can axial and induced velocities with the 𝑍 axial and tangential induced velocities with the (3) �� can be approximated as (2) (3)(3) these ⎫ bladed (2) � � (10) 𝑍 ()𝑟𝑟�functions (3) 𝑢�(repectively. = 𝑍 𝑍 (𝑦((For 𝑦 − 2𝑍𝑟 𝐹��⎫))⎫ a � 𝐹finite propeller, ∗ the ∗that )))𝑢�= �𝑟�( ��𝐹 𝑦 2𝑍𝑟 −− 2𝑍𝑟 Note this velocity isoriented oriented at certain angle � � )a)at (velocities ) + induced )𝑉 )�angle axial and tangential velocities with �𝑉 �𝜔𝑟 � � Note that this velocity oriented angle and effective inflow inin axial 𝑉that = 𝑟velocity 𝑢∗� (velocity 𝑟is)� + + 𝑟(𝑉 + 𝑢certain 𝑟angle Note that this is oriented aacertain certain Note this velocity at𝑉at and effective inflow axial (= (��(𝑦(𝑛, 𝑟��)� −)𝑚 2𝑍𝑟 �velocities �a((at 𝑍 4𝜋𝑟 ((�𝑛= )⎪)� 𝐹�)⎫ � �( ⎪ ⎪ (2) ) � 𝑢𝑢�𝑢∗��𝑢∗��𝑟 � 𝑢 � (3) � �𝑟 𝑛 � = 𝑢 � 𝑛, 𝑚 � �= ΓΓ Note that this is oriented a certain angle( βi ) 4𝜋𝑟 4𝜋𝑟 � � � � ⎪ � ⎫ functions be approximated as )� = 4𝜋𝑟 𝑢� (𝑟� can 𝐹𝑟��)𝑟𝑟⎪ for < 𝑟�� (�𝛽 )with � (𝑦 − 2𝑍𝑟 𝛽)respect with respect to theplane plane of rotation. 𝛽itself itself � < �for ) ( 𝑟 for < 𝑟 Note that this velocity is oriented at a certain ( ) and effective inflow velocities in axial 𝑉 ( ( ( �) � itself ) tangential 𝑉 directions and the rotational speed with respect to the plane of rotation. 𝛽 𝛽 respect to the of rotation. 𝛽 tangential 𝑉 directions and the rotational speed � � � ( ) � � � 𝑢∗� �𝑟� (𝑛�)𝑍��𝑍 Γ 𝑢 � 𝑛, 𝑚 � � � 𝑍= � with to the plane of rotation. β itself can be given for 𝑟 < 𝑟 4𝜋𝑟 ( ) �� 𝛽� with respect to the plane of rotation. 𝛽� angle itself �� (3) ⎬ �� ⎬ ⎬ 𝑍𝑦 𝑍 i ( ) 𝑢 � 𝑟 = 𝐹 can be given as follows for 𝑟 < 𝑟 ⎫ ) ⎬ ( ) 𝛽 with respect to the plane of rotation. 𝛽� itself ( ) ( ) ( ) tangential 𝑉 directions and the rotational speed � � � � ⎪ � � ( ) 𝑦𝐹��𝐹 𝑢��𝑢��𝑟𝑢 =𝑟𝑢��=) (2𝜋𝑟 𝑦= of propeller 𝜔𝑟 , the resultant of an inflow can be given as follows can be given as follows (𝑦 ) of propeller , the resultant of an inflow = 2𝑍𝑟 𝐹 �𝜔𝑟 � �� − ⎪ ��𝑟��( �� ⎪ � � ) Note that this velocity is oriented at a certain angle 𝑍 𝑟 𝑦 𝐹 can be given as follows ⎪ ⎪ where u̅ a and u̅ t denote horseshoe function as follows � 2𝜋𝑟 �the � � ⎭⎭ ⎬ 2𝜋𝑟 ⎭influence ��= �2𝜋𝑟 �)4𝜋𝑟 (𝑟𝑟of 𝑉(��𝑟((resultant +𝑢�∗𝑢 𝑢�∗�∗𝑟the (11) (be ), the can given ))by ))of )𝑟𝑟the velocity be computed of propeller 𝜔𝑟 � 𝑦� 𝐹 𝑉 + (11) 𝑉�as + ∗an velocity can be computed by following ⎭ � ⎪influence where the horseshoe � where 𝑢�𝑢�� and and𝑢�𝑢��𝑢�(��𝑟�denote denote horseshoe influence �� for 𝑟� < 𝑟�(4) ((can (𝑟(the )()+ (𝑟(11) )inflow 𝛽 with respect tofollows rotation. 𝛽(11) �𝑍� 𝑉 𝑢following �� (4) � 2𝜋𝑟�the 𝛽 𝑟 = tan � �))= � itself �plane (4) 𝑍 ) 𝑍 ( ) ∗ (�� ) � repectively. � 𝛽 𝑟 tan � 𝛽 𝑟 = tan � ⎭ �� ⎫ 𝑍 of axial function and tangential velocities, For a finite ∗ (𝑢�� ⎬ ⎫ ⎫ ( ) (4) ∗ ∗ 𝑉 𝑟 + 𝑟 𝑍 ( ) velocity can be computed by the following ( ) 𝛽 𝑟 = tan � � (11) equation 𝑢 � 𝑟 = − 𝑦𝑦 𝐹 ( ) ) equation 𝜔𝑟 + 𝑉 𝑟 + 𝑢 𝑟 where 𝑢 � and 𝑢 � denote the horseshoe influence of axial and tangential velocities, � � function axial and velocities, )(𝑢�𝑟= )𝑟��= � given𝜔𝑟 �𝐹 �tangential ⎫ 𝑦𝑦 𝐹 ( ) ( ) 𝑢��𝑢�(��𝑟�(�𝑢�of 𝑦𝑦 𝐹 ( ) ( ) � � � ∗ ⎪ )(− 𝜔𝑟 + 𝑉 𝑟 + 𝑢 𝑟 + 𝑉 𝑟 + 𝑢 𝑟 � �� = 𝑦 can be as follows � � � � � � ⎪ ⎪ �− � � ⎪ � � ) (4) =��− 𝑍 𝑦𝑦� 𝐹� (𝑟 )� 2𝜋𝑟 + 𝑉� (𝑟 ) +�𝑢 � 𝑟 ⎪> �= bladed propeller, befor approximated as equation 𝛽� (∗𝑟∗) =��tan �𝑉𝜔𝑟 � and for 𝑟�these � �∗(10) (10) ⎭ 2𝜋𝑟 )2𝜋𝑟 function these of axial tangential repectively. For a��𝑍 finite bladed 𝑢�� (2𝜋𝑟 𝑟functions − 𝑦𝑦 (𝑢�𝑟∗∗∗(()(𝑟𝑟𝑟+ repectively. For a2𝜋𝑟 finite bladed propeller, 𝜔𝑟 for 𝑟� 𝑟𝑟⎫ > 𝑟velocities, �can ))�𝑢 � 𝐹�propeller, �𝑢 �� > �𝑟� ⎪ � (𝑟 ) (11) )� �� ()𝑟𝑟)+ )𝑉 𝑟𝑟))++𝑢𝑢��((𝑟𝑟)� ++�𝜔𝑟 ++ 𝑢 �𝑉 �𝜔𝑟++ �𝑉( for 𝑟these > 𝑟�(4) 𝑉𝑉∗ ∗==��𝑉 𝑉�𝑟�(+ ��(( � 2𝜋𝑟� � � )� � ⎬ 𝑍 𝑍 ⎬ ⎬ 𝑍 ( ) � � per unit radius �� (10) 𝛽 𝑟 = tan 𝑍 ( ) ( ) repectively. For a finite bladed propeller, these functions can be approximated as Therefore the force directed atthe the 𝑢 � 𝑟 = 1 + 2𝑍𝑦 𝐹 for 𝑟 > 𝑟 functions can be approximated as � ∗ ⎫ ∗ ⎬ ∗ ∗ ( ) ( ) ( ) ( ) � � � � ⎪ � � the per radius the 1+ 2𝑍𝑦 the unit radius atat 𝑢��𝑢��𝑟�𝑢�𝑟�= 1+ ��𝑉� (Therefore (𝑟force )�the )unit ((𝑟directed �𝜔𝑟 ��𝐹2𝑍𝑦 �⎪ ⎪ 𝐹 ) ��𝐹 𝑉 Therefore =Therefore 𝑟) + 𝑢�force +per +unit + 𝑢𝑢�directed (𝑟𝑢�=�)(4𝜋𝑟 𝑦𝑦 𝐹 (1 𝜔𝑟 + 𝑉𝑉�per + 𝑟)�) directed �((𝑟𝑟) 𝑍2𝑍𝑦 force at the 𝑟=��)− = + 4𝜋𝑟 � ⎪ �radius ⎬ (3) ⎭ �⎪ ��=2𝜋𝑟 ∗∗ the ∗𝑉 𝑍 𝑢��4𝜋𝑟 ⎭ ⎭ functions 𝑍�can be approximated as (3) can be obtained and given as right angle to 𝑉 ( ) ( ) 4𝜋𝑟 � Therefore force per unit radius directed at theright 𝑟 1 + 2𝑍𝑦 𝐹 � can be obtained and given as right angle to can be and given as right angle to 𝑉 ∗obtained �−2𝑍𝑟 � �for ⎪ ⎭ ⎫ ⎫ 𝑟 > 𝑟 Therefore the force per unit radius directed at the (�(𝑦𝑦− ) ) 𝑢�𝑢��((𝑟�𝑟�))== 𝐹 2𝑍𝑟 𝐹 can be obtained and given as right angle to 𝑉 � � �� ⎪⎪ Note velocity is= at(at𝑟a)acertain Notethat thatthis thisright velocity istooriented oriented certainangle angle ⎭ (3) 𝑍� 𝑍 4𝜋𝑟 ∗ (∗∗∗ ( ( ) ( ) (12) 4𝜋𝑟 𝐹 𝑟 𝜌𝑉 𝑟 Γ 4𝜋𝑟 ⎬ can be obtained and given as angle 𝑉 � ( ) ) ( ) ( ) ) ( ) (12) (12) 𝐹 𝑟 = 𝜌𝑉 𝑟 Γ 𝑟 𝐹 𝑟 = 𝜌𝑉 𝑟 Γ 𝑟 ⎫ ∗ (where (𝑦 − 2𝑍𝑟 (1� 𝐹 𝑢��where 𝑟where Therefore unit the 𝑢��(�𝑟� ) = +�)2𝑍𝑦 (𝑟oriented ) =per (at𝑟 )aradius (given 𝜌𝑉rotation. Γcertain 𝑟)𝛽𝛽� � directed for �) = for�𝑟�𝐹 𝑟��<)<⎪𝑟�𝑟� ((𝛽𝛽�Note that this is angle at (12) to V* velocity can be𝐹force obtained as )with respect totothe the plane ofof with respect the rotation. itself ⎪ ∗and �)angle 4𝜋𝑟� where 𝑍𝑍4𝜋𝑟 ) =be (𝑟 )Γ(𝑟and ) itself (12) 𝐹∗(plane 𝑟can 𝜌𝑉 � �.�� ⎭< 𝑟 1 ⎬⎬�.�� .�� obtained given as right angle to 𝑉 � � for 𝑟 1 1 + 𝑦 1 ( ) 𝛽 with respect to the plane of rotation. 𝛽 itself 𝑢�𝑢��((𝑟�𝑟�))==𝐹 ≈where 𝑦 𝐹 �.�� can be given as follows � �1 1 𝐹�� 1�+ can �beThe giveneffect as follows �⎪ 1+ 𝑦 � �11 �1 � ofviscous viscousdrag drag maybebe beincluded included by �⎪ −�𝑦�12𝑍𝑦 + 1��𝑦 1⎬ +� 𝑦�� 124𝑍 1 �2𝜋𝑟 �� ∗( ) Theeffect effect The ofof byby ��−� 1 + ≈ 𝐹 𝐹2𝜋𝑟 ≈ −𝑍 �� .��−�+ �− ∗∗(drag � �2𝑍𝑦 𝑦��⎭�⎭ 𝑈�� 1+ (𝑟) (11) (12) = 𝜌𝑉 Γmay The drag mayincluded be included by 𝐹2𝑍𝑦 + 24𝑍 24𝑍 ((viscous )𝑟) may 12𝑍𝑦 + 𝑦 −− 11 𝑢�� (𝑟� )�where = can be given as effect follows (𝑟𝑟𝑟)))of (𝑟force 𝑉𝑉𝐹 + 𝑢viscous �𝑦�≈ 1𝑦 1⎪ +𝑈𝑦 𝑦��𝑈 124𝑍 1 �� + 𝑢 𝑟 (11) �1 �𝐹 �+ � � � � 1 + 𝑈 − 1 � adding the viscous drag acting in a direction � �� The effect ofdrag viscous may be included by � 2 ⎭ �� 1 (4) 𝐹 + 24𝑍 adding the viscous force ina adirection direction drag force acting inacting �− (4) 𝑍+ � 2𝜋𝑟 �2 )= 𝛽𝛽� �((𝑟𝑟)adding ��viscous �drag ∗∗drag =tan tanthe �acting 9𝑦 + 2� ≈� − � �− 3𝑦 2𝑍𝑦 adding the viscous force in a direction ⎫ 1 + 𝑦 𝑈 − 1 �� 𝑍 ⎫ 9𝑦 9𝑦 + 2 ( ) ( ) 3𝑦 − 2 3𝑦 2 ∗ 1 1 𝑉 𝑟 + 𝑢 𝑟 (11) �.�� ∗ � � � ( ) � � � � −− � 9𝑦 �1 �� 𝑢�𝑢�� (𝑟�𝑟��)=�= 𝑦𝑦 𝐹 ((𝑟∗𝑟)the + ln + 1 �� (4) ∗the ∗𝑉+ 2 𝑦𝑦 )+ 3𝑦 − �1 2+ + �+ )direction 𝜔𝑟 + 𝑉��viscous +𝑢 𝑢�drag (in �� is parallel to𝜔𝑟 . 𝑉Once Once the drag coefficient 𝐶�� + �1 ��ln �� ln �1 ��+ � �.� � +1�𝑦+ 1(𝐹 𝑦 11 �� .� ⎪ adding force acting a is ⎪ ) ( ) ( �((𝑟𝑟)) �� is parallel to 𝑉 . the drag coefficient 𝐶 parallel to 𝑉 . Once drag coefficient 𝐶 ( ) � �� 𝑦 �� 𝑍 ( ) � �.� �.� (+ ) 𝑈 − 1 �.� �.� 𝛽 𝑟 = tan � � 1+ + � � �1 �� + ln + 2𝜋𝑟 ) ( ) 2𝜋𝑟 ) ( ( ) 1 + 𝑦 𝑈 − 1 ( ) 1 + 𝑦 𝑈 − 1 � � The effect of viscous drag may be included by adding The effect of viscous drag may be included by � � � 9𝑦 + 2 ⎫ 𝐹 ≈ − + 1 𝑦 1 𝑦 3𝑦 − 2 is the parallel to 𝑉 . Once the drag coefficient 𝐶 ∗( ) ��1− 1 � 𝑦𝑦 �� (�1 𝑦�𝑟)�𝑟��.� 𝑢�� (𝑟� ) = − 𝐹�1++( 1𝑦 �+ ) +bebe 𝑦��)��.� for > 𝑟ln�𝑟−�11+ 𝑈24𝑍 𝜔𝑟 +force 𝑉�∗ .(can 𝑟Once 𝑢 𝑟 drag coefficient for 𝑈> � +�2𝑍𝑦 �� determined, this force can becomputed computed asfollow follow (𝐶�� ⎪ �the parallel to 𝑉 determined, this can computed follow determined, this force asas �.� �� ) is 𝑍𝑍 2𝜋𝑟 (�⎬1 (�1 + + 𝑦� )�.� � 𝑈 �� − 1 adding the viscous drag force acting in a direction determined, this force can be computed as follow � 𝑦� ) ⎬ viscousthe drag force acting in acan direction to V*. Once 𝑟� > 𝑟� 1 (�(11+ Therefore force per directed atatparallel the 𝑢�𝑢��((𝑟�𝑟�))== 9𝑦 ++22𝑍𝑦 𝐹3𝑦 Therefore the force per unit unit radius directed the as follow 2𝑍𝑦 𝐹 ))⎪− 2 for determined, this radius force becoefficient computed � �𝑍 +�(� �� ⎪ (𝐶�� ) is 4𝜋𝑟 parallel to 𝑉 ∗per . Once the drag �⎬ �.� � ln �1 + 𝑈 �� − 1 �� ∗∗force ) ⎭ (1 �+ 𝑦(��1)�.� 1�+ 𝑦 ) Therefore the unit radius directed at the 𝑢�� (𝑟� ) =4𝜋𝑟 + 2𝑍𝑦 𝐹⎭ the drag coefficient (C ) is determined, this force can be can be obtained and given as right angle to 𝑉 and given as right angle to 𝑉 can be obtained � ⎪ Dv can 4𝜋𝑟� determined, this force be computed as follow ∗ ⎭ ∗∗(be ( ) ) ( ) can obtained and given as right angle to 𝑉 (12) ( ) ( ) ( ) 𝐹 𝑟 = 𝜌𝑉 𝑟 Γ 𝑟 (12) 𝐹 𝑟 = 𝜌𝑉 𝑟 Γ 𝑟 computed as follow where where where (12) 𝐹 (𝑟) = 𝜌𝑉 ∗ (𝑟 )Γ(𝑟) �.�� where 11 11++𝑦𝑦�� .�� 11 11 ∗may �� be The effect of viscous drag may included �� .�� ( ) ( ) ( ) ( ) by (13) 𝐹𝐹 ++24𝑍 The effect of viscous drag be included ≈−−2𝑍𝑦 𝐹 𝑟 = 0.5 𝜌�𝑉 𝑟 𝑐 𝑟 𝐶 𝑟 ��≈ � ∗ � �� 2𝑍𝑦�1� 11++ ((�𝑟 )) = 0.5 𝜌�𝑉 ∗ ((𝑟))��𝑐((𝑟 ))𝐶�� ((𝑟)) by(13) 𝑦 𝑦� 𝑈𝑈 −−111 24𝑍1 𝐹 1𝑦+ (13) � Ta 𝑟of = 0.5 𝑟acting ��𝑐 𝑟be 𝐶�� 𝑟 The the effect viscous drag may by � �� adding drag force inin aaincluded direction 𝐹 ≈− + adding the𝐹viscous viscous drag𝜌�𝑉 force direction � Tab ∗ ( )�acting (13) 9𝑦 1+ 𝑈 − 11 24𝑍 −−𝑦22 9𝑦��++22 2𝑍𝑦�3𝑦 3𝑦 ) = 0.5drag (𝑟 )𝐶in ((𝑟(direction ) ))(13) 𝐹 𝑟 𝜌�𝑉 𝑟 � 𝑐 Tab ∗(viscous ∗ ∗ � �� .� � �1 �� + ln + � �1 �� + ln + adding the force acting a � ( ) ( ) ( ) ( ) isiswater parallel to 𝑉𝑉 . .= Once the coefficient 𝐶𝐶the parallel to Once the drag coefficient �.� 𝐹 𝑟denotes 0.5 𝜌�𝑉 𝑟∗ ( �mass 𝑐density 𝑟(density 𝐶 𝑟of ��− �.� where thedrag mass and where denotes the thewater and c(r) the �� ρ (13)and ((11++ 𝑦𝑦��))− 𝑈𝑈�� Tab −111 𝑦𝑦 ))+�.�2 ((11++ 9𝑦 3𝑦 2 r/R (𝑟of )the 𝐹� (𝑉𝑟𝜌∗)𝜌.denotes =Once 0.5 𝜌�𝑉 𝑟)∗��coefficient 𝑐density 𝑟�)�� 𝐶��of where the mass water Table (13) � �� .� + � �1 �� r/R ) (13) ((𝐶𝑟�� is and parallel to the determined, this force be computed follow where 𝜌𝐹the the mass of the (= (𝑟at𝑐density )(�Integrating (as )water determined, this force can be computed as)radius. follow ∗drag 𝑟 )at =can 0.5 𝜌�𝑉 𝑐 𝑟 𝐶 𝑐(𝑟) chord length any Integrating ( 1 + 𝑦� )�.� ln + 𝑈 �� − 1 � Tab (1 + 𝑦� ) �denotes �� r/R ( ) ( ) ) ( ) chord length any radius. these forces over 𝐹 𝑟 0.5 𝜌�𝑉 𝑟 � 𝑟 𝐶 𝑟 ∗at (13) � the 𝑐(𝑟) length where 𝜌𝐹 the𝜌�𝑉 mass of the and (chord ) =over (𝑟density )any (radius. (water )water 𝑟force 0.5 � 𝑐and 𝑟�� 𝐶 𝑟Integrating determined, this can be radius computed follow �denotes �� r/RTab 𝑐(𝑟) chord length at any radius. Integrating �.�� 0.1848 where 𝜌the denotes the mass density of)as the andover these forces the summing up d length is then r/R 1 1 + 𝑦�� 1 1 the 𝑐(𝑟) radius summing up over the of blades will 0.1848 these forces over the radius and summing up over where 𝜌and denotes the mass of number theIntegrating water and the chord length at density any radius. � � � r/R 𝐹 ≈ − � �.�� − 0.1848 these forces over thethe radius and summing up over 0.2000 the number oflength blades allow us the to the total where 𝜌 denotes mass density of get the water and 𝑐(𝑟) the atwill any radius. Integrating 𝑦𝑦��1 �.�� 𝑈 − then reduces to (5) 𝑦1� � 11 + 1 � 1 +2𝑍𝑦 11 1 24𝑍 where 𝜌chord denotes the mass density of water and 0.2000 the number of blades will allow us to get the total drtex length is then 0.1848 + 𝑐(𝑟) the chord length at any radius. Integrating 1 these forces over the radius and summing up over r/R r/R � allow us to get the total propeller thrust and torque. where 𝜌 denotes the mass density of the water and �≈ � � 𝐹� ≈ − 2𝑍𝑦𝐹9𝑦 − 0.2000 � − the number of blades will allow us to get the total 0.2500 0.1848 � � � � − � these forces over the radius and summing up over propeller thrust and torque. r/R 𝑐(𝑟) the chord length at any radius. Integrating � �− − 2 3𝑦 𝑈 1 24𝑍 1 𝑦 achtoblade with �1++2 es (5) 2𝑍𝑦 𝑈 − 1 24𝑍 1 + 𝑦 � 𝑐(𝑟) the chord length at any radius. Integrating 0.2500 �.�� 0.1848 ortex reduces to (5) propeller thrust and torque. 0.2000 these forces over thetorque. radius and summing up over the number blades will allow us to get the total � � of ength is then 𝑐(𝑟) the chord length at any radius. Integrating 1� (+1 𝑦+��𝑦 � )�.� � ln1�1 + 𝑈1− 1�� 1 0.2500 �.� + propeller thrust and 0.2000 0.3000 0.18 � the number of blades will allow us to get the total ) ( (14) these forces over the radius and summing up over � � 1 + 𝑦 � ∗ )� summing � 2 3𝑦� �− 2 � 1 − 1 � 2− l. the9𝑦� + 2𝐹� ≈9𝑦−� 3𝑦 0.1848 + these over the radius up(14) over 0.3000 [of (𝑉and 0.2000 with achBeacuse blade to with 𝑇number =forces 𝜌𝑍 �� 𝑉 ∗Γ cos 𝛽torque. − 0.5 𝑐𝐶 sin 𝛽� ] 𝑑𝑟 0.2500 the blades will allow us get the total propeller thrust and −�1 1 + � the �� to 1 +�𝑦ln �1 0.18 ex reduces over radius and summing up total over � �+ � + 2𝑍𝑦 � ln � +𝑈 ��24𝑍 �� (5) 0.3000 [�𝑉 ∗∗Γand ��forces 𝑇 =these 𝜌𝑍 number cos 𝛽 𝑉 ∗∗ )�� 𝑐𝐶 𝛽� ]to 𝑑𝑟get (14) 0.2500 0.4000 0.20 propeller thrust torque. �.� the of blades will allow the � − 0.5 ( �� sinus (1� + 𝑦 � )�.� 𝑈 − 1 𝑈 − 1 (1� +(1𝑦��+)�.� ) (1 + 𝑦�� )�.� yl.the will have the 0.2000 𝑦 � of [ ( ) ] � 𝑇 = 𝜌𝑍 𝑉 Γ cos 𝛽 − 0.5 𝑉 𝑐𝐶 sin 𝛽 𝑑𝑟 the number blades will allow us to get the total 0.4000 0.2500 Beacuse the 0.3000 � �� propeller thrust and torque. (14) �� ∗ 9𝑦� + 2 �number 3𝑦 − 2 1 0.20 with h blade with ∗ � the of blades will allow us to get the total 0.4000 0.3000 0.5000 0.25 [ ( ) ] � (14) 𝑇 = 𝜌𝑍 𝑉 Γ cos 𝛽 − 0.5 𝑉 𝑐𝐶 sin 𝛽 𝑑𝑟 �� propeller thrust and torque. (15) � + � ln �1 + �� ∗ ∗ � ∗ ∗ � rcumferentially 0.2500 � �.� � � �.� thrust 0.5000 with (0.5 0.3000 yBeacuse will have the 𝑇propeller =𝑄 𝜌𝑍 Γ[∗cos 𝛽sin 0.5 𝑉 )(∗𝑉 𝑐𝐶 sin ( +1𝑦 ) 𝑈 −1 0.4000 (1 + 𝑦𝑦� )�1 (15) =�𝜌𝑍[�𝑉�� 𝑉 Γand 𝛽torque. 𝛽� ] 𝑟𝑑𝑟 (14) � −and � ] 𝑑𝑟 the � 0.25 � + torque. ��𝛽cos � )��𝑐𝐶 the propeller thrust + 𝑦 �1− 0.5000 [ ] ( ) with � 0.4000 0.6000 (15) 𝑇 = 𝜌𝑍 𝑉 Γ cos − sin 𝛽 𝑑𝑟 � 𝑄 sin 𝛽 + 0.5 𝑉 𝑐𝐶 cos 𝑟𝑑𝑟 0.30 � (14) with �� [�𝑉 ∗ 𝛽� + 0.5 (𝑉 ∗ )(� 𝑐𝐶 ∗ �� cos 𝛽� ] 𝑟𝑑𝑟 can be chosen 0.3000 𝑈=� exp ��1 + 𝑦 � − �1 + 𝑦�� ∗∗�Γ 0.6000 𝑄 =𝑇𝜌𝑍 sin 0.4000 [𝑉 rcumferentially � = 𝜌𝑍 Γ𝛽cos 𝛽� ] 𝑑𝑟(14) 0.5000 ∗ )�𝑉 )��𝑐𝐶 � −𝛽0.5 �] 𝑑𝑟 (15) �� [𝑉 � − (0.5 ��𝛽sin � 0.30 allyhave the will � (14) � 𝑇 = 𝜌𝑍 𝑉 sin ∗Γ cos ∗) � 𝑐𝐶 0.6000 𝑦�1 + 𝑦 − 1 0.7000 0.5000 ∗ ∗ � 0.40 � �� + 𝑦 − 1 𝑦 [ ( ] �1 � (15) 𝑄 = 𝜌𝑍 𝑉 Γ sin 𝛽 + 0.5 𝑉 𝑐𝐶 cos 𝛽 𝑟𝑑𝑟 � � � �� [𝑉 Γ cos 𝑇� = [𝜌𝑍 (6) � ∗� � 𝛽� (− ∗0.5 � 𝛽� ] 𝑑𝑟 � (𝑉 )��𝑐𝐶��]sin 0.4000 � − �1 + 𝑦 �� 𝑦=��−𝑟�1 𝑦�with �1 + 0.7000 0.5000 can be chosen ) 0.6000 𝑈 exp ��1 + 𝑦 𝑄 = 𝜌𝑍 Γ sin 𝛽 + 0.5 𝑉 𝑐𝐶 cos 𝛽 𝑟𝑑𝑟 �𝑉 (15) � � 1 𝑉 � � �� 0.40 � ∗ ∗ � umferentially � � 0.7000 osen � exp ��1 � � 𝑈=� − �1 + 𝑦 �� + 𝑦 � [𝑉��Γ sin 𝛽 + 0.5 (𝑉 ) 𝑐𝐶 0.8000 0.6000 ] 0.50 � 𝑄 = 𝜌𝑍 cos 𝛽 𝑟𝑑𝑟 � � 𝑦�1 + 𝑦 − 1 (15) � The propeller thrust and torque may be � �� 𝑦= ; tan 𝛽 = � ∗ ∗ � 0.5000 1� = 𝑦�� 11+ 𝑦 ;−� 𝑦 0.8000 (6) 0.6000 0.7000 ] 𝑟𝑑𝑟 (15) 𝑦�1 �∗�Γ[𝑉 𝑄 = 𝜌𝑍 Γ sin 𝛽 + 0.5 𝑐𝐶 cos 𝛽 The propeller thrust and may be ∗ )(�𝑉 )torque 0.50 � � �� tan1 𝛽+ 𝑦 � − �1 + 𝑦𝜋𝑟 n be chosen 𝑈+ = �𝑦�𝑟�−tan �� exp ��1 0.8000 [ ( ] (15) � � 𝑄 = 𝜌𝑍 𝑉 sin 𝛽 + 0.5 𝑉 𝑐𝐶 cos 𝛽 𝑟𝑑𝑟 𝑟� 𝛽� 𝑉 (6) 𝑉� 0.7000 0.9000 0.60 � + ∗ ∗ � The propeller thrust and torque may be � �� nondimensionalized with respect to the advance [ ( ) ] �� 𝑉 Γ sin divided into 𝑀 𝑟� 𝑦 =𝑦�1 + 𝑦� − 𝐽� 𝑄 = 𝜌𝑍 𝛽� + 0.5 𝑉 𝑐𝐶to cos 𝛽�advance 𝑟𝑑𝑟 may 0.6000 0.9000 0.7000 ;1 1𝑦� = ; tan𝑉 𝛽� = 𝜋𝑟 �� torque 0.8000 Thenondimensionalized propeller thrust and be0.8000 �� with respect the The propeller thrust and torque may be 0.60 (6) 0.9000 𝑟 tan 𝛽 tan 𝛽 0.9500 0.70 �as 𝑦= ; 𝑟𝑦 ; tan 𝛽 = nondimensionalized with respect to the advance �� = + 𝑉 � follow coefficient The propeller thrust and torque may be 1 𝑉 the hub radius, � 𝜋𝑟 0.7000 � � 0.9500 0.8000 (6) advance coefficient divided into 𝑀𝑟� tan 0.9000 𝛽 coefficient as follow The propeller thrust and torque may be advance0.9000 � in Eq. ; tan nondimensionalized with respect to the advance 0.70 𝑦 𝐽= 𝑦� 𝛽 =represents ; tanthe 𝛽 =+ 𝑉� 𝐽� nondimensionalized with respect to the 0.9500 1.0000 𝜋𝑟 0.80 8𝐾 coefficient as follow nondimensionalized with respect to the advance othe 𝑀hub 𝑟radius, 𝐽 � (16) The propeller thrust and torque may be 𝑟 tan 𝛽 tan 𝛽 0.8000 ropeller = 𝑅. � � + 𝑉 1.0000 8𝐾 0.9000 given TheThepropeller torque be be 0.9500 � coefficient � � and (16) 𝐶thrust = nondimensionalized with respect totorque the may advance 𝐽� represents in as Eq. (6) the represents the advance coefficient as follow 0.80 ided intoJ 𝑀in Eq. (6) 𝐽� � 1.0000 8𝐾 propeller thrust and may 0.9500 0.90 advance coefficient given as coefficient as follow � (16) 𝐶 = coefficient as follow 𝜋𝐽 nondimensionalized respect to the advance dius, mber of panels. 0.9000 � with � respect 0.9500 in Eq.given (6) as represents the𝑉�advance coefficient (7) 𝐶�� = 8𝐾 nondimensionalized with to the advance 𝑟𝐽s= 1.0000 𝜋𝐽 coefficient as follow � 𝑅. � (16) 0.90 � eropeller hub radius, � with respect to the advance nondimensionalized 𝐽 in Eq. (6) represents the advance coefficient 1.0000 0.95 8𝐾 𝐽 = The main 16𝐾 𝜋𝐽 � � (16) 𝐶 = coefficient as follow (17) � �� 0.9500 � be ingiven the as = 𝑅. put 1.0000 8𝐾 The main coefficient as follow 16𝐾 mber of panels. 𝑉 𝐶 = 𝑛𝐷 � (17) � (16) (7) 𝐶 = 0.95 𝜋𝐽 � � peller 𝑟= 𝑅. � � coefficient 𝐶 as follow The main � � 16𝐾 �� given as 1.00 8𝐾 nondimensio (17) 𝐶 = = 𝜋𝐽 (16) 𝐽 = 𝜋𝐽 1.0000 8𝐾 ade where �=�� nels. nondimensiona (16) in the the 𝐶�� =𝐶16𝐾 𝑉� � 𝑉 𝑛𝐷 The main (7) 𝜋𝐽 1.00 � (17) 8𝐾 erbeofput panels. � � � � nondimensiona � (16) (7) 𝐶 = The main in � 16𝐾 represented � 𝜋𝐽 � � (17) 𝜋𝐽 � 𝐶 = where 𝐽 = � and where tangential =�� 𝐶16𝐾 represented 𝐽� =is the number of propeller The main by �𝜋𝐽 lade where 𝑛� = 𝑛𝐷 nondimensiona 𝐶� = (17) where 𝜋𝐽 e the put in thethe � represented by 𝜋𝐽 �� nondimensionaliz The main 16𝐾 propeller cho 𝑇 𝑛𝐷 where � 𝐶 = � (17) 𝜋𝐽 (18) � � eand velocities are The main 16𝐾 �= nondimensiona tangential propeller chord � (17) 𝑇��16𝐾 represented by (18) 𝐾�= 𝐶= 𝜋𝐽 where 𝑛 =per second. is the number of propeller revolutions It should be noted here that The main where ethe where the � � (17) propeller chord 𝑇 � � 𝐶 represented by shown in Ta nondimens (18) 𝐾�� =𝐶 = �� 𝜌𝑛 where 𝜋𝐽 orseshoe vortex nondimensiona �� 𝐷�� shown in Tab ed velocities are represented by � 𝐾 = 𝜋𝐽 � propeller chord 𝑇 𝜌𝑛 𝐷 � where the cosine spacing described in Dannecker (1997) nondimens � (18) ntial tangential � shown in Tab per second. It should noted here thatper where where w hof e r e where isisthe number of propeller revolutions is the number propeller where 𝑛revolutions = 𝑛= the number of beofpropeller parameters u represented propeller chord 𝑇 � 𝐷𝑄𝜋𝐽 � (19) (18) 𝐾� = 𝜌𝑛 tex segment represented by �� 𝑄 orseshoe vortex parameters use �� 𝐷� propeller chord 𝑇 where shown in Tab (19) 𝐾 = 𝐾 = (18) 𝜌𝑛 and Kerwin (2011) is adopted for the vortices and represented velocities are � � are 𝑄 parameters use �𝐷 � the cosine spacing described in Dannecker (1997) � � where shown in Table Table 2. An (19) 𝐾 propeller c 𝑇 = 𝜌𝑛 𝜌𝑛 𝐷 (18) per It should bethe noted here nes of strength revolutions per second. should bethat noted thatthat propeller 𝑇 � 𝐷� second. Itcontrol should be second. noted here cosine spacing Table 2. Ano tex segment of revolutions shown in chord Tab 𝐾�� = (18) parameters use 𝐾�𝜌𝑛 =𝑄 (19)(18) points inIt above equations tohere compute the eshoe vortex � 𝐷 �𝑇 propeller c𝑪 Table 2. Ano rtex and Kerwin (2011) is adopted for the vortices and � 𝐷� ( 𝐾 = 𝑄 parameters used 𝜌𝑛 shown in coefficient (19) � 𝐾 = 𝜌𝑛 the cosine spacing described in Dannecker (1997) � � ity atof𝑟�strength can becosineinspacing � 𝐾�𝜌𝑛 shown Tab =𝑄 ((in the described inand Dannecker (1997) �𝐷 �� coefficient 𝑪 parameters use Table 2.in Ano 𝐾� = (19) 𝑫 described Dannecker (1997) Kerwin (2011) is adopt𝜌𝑛 𝐷 vortex lattice grid, which can be given as: xnes segment of shown � � control points in above equations to compute the coefficient 𝑪 𝜌𝑛 𝐷 2.velocity Anoth 𝑄 titydirections of 𝑟 can be parameters ship 𝑫 𝐾� = Therefore, finally efficiency of propeller can be Table 𝜌𝑛the 𝐷𝑄 (19) and Kerwin (2011) is adopted for the vortices and parameters �𝐷 � (19) ship velocity Table 2. Ano (use andas Kerwin (2011) is+grid, adopted Therefore, finally of propeller can be coefficient 𝑪((𝑫 𝐾the =efficiency � ed (𝑚 ) lattice [ 1 which (points (8) 𝑟�vortices = 𝑟�and ℎcontrol − cosfor 2 (the 𝑚be−vortices 1)above 𝛿 )]as: and 𝑄 sngth ofatstrength parameters �𝜌𝑛 (19) ship velocity vortex can given � � for the in equations 𝐾 = ( Therefore, finally the efficiency of propeller can be Table 2. A coefficient 𝑪 velocity to � 𝐾 =�𝜌𝑛�as𝐷(Carlton, 1997) obtained and computed control points in above equations to compute the 𝑫𝒗 Table 2. Ano (𝑪 as points 𝐷 �𝜌𝑛efficiency velocity to sh coefficient obtained and computed as 1997) shipTable velocity (𝑫A control in= above equations to compute the �(Carlton, � Therefore, finally the of propeller can be ship 2. yl atdirections 𝑟� canto becompute 𝜌𝑛 𝐷 ( ) [ ( ( ) )] (8) 𝑟 𝑚 = 𝑟 + ℎ 1 − cos 2 𝑚 − 1 𝛿 ( ) [ ( ) ] velocity to sh (9) obtained and computed as (Carlton, 1997) 𝑟 𝑛 𝑟 + ℎ 1 − cos 2𝑛 − 1 𝛿 𝐽 𝐾 velocity (𝑽 coefficient defined to b (20) � � Therefore, finally the efficiency of propeller (20) can be vortex � the �grid,lattice � � vortex lattice which grid, can bewhich givencan as: be given as : 𝑨 n be (1) coefficient 𝑪 𝐾 shipcoefficient velocity defined to Therefore, finally efficiency of propeller can be �as (Carlton, velocity to (be sh(𝑫 obtained and computed 1997) 𝜂 the =𝐽𝐽�� as lattice grid, 𝑟which cancos be given as: directions vortex as 𝐾 Jurnal Teknik BKI bevelocity defined to be (20) �(Carlton, ship toveloci ship assumed mo obtained and finally computed 1997) 𝜂 = Therefore, finally the efficiency of propeller can 𝑟� ()𝑛=) = ℎ[− 1− 2𝑛−−11))𝛿𝛿)]] (8)(9) 𝑟� +� + ℎ[ 1 cos(2 (𝑚 2𝜋𝐾 s as (1) ( ) 𝑟� (𝑚 ship velocity ( � Therefore, the efficiency of propeller can be assumed movi 𝜂 = 2𝜋𝐾 velocity to sh 𝐽 𝐾�as obtained and computed (Carlton, 1997) to be (20) can be defined 02Desember ship 𝑟� 𝑚 = 𝑟� + ℎ[ 1 −(�� cos)(2 (𝑚 − 1)�𝛿 )] (8) � efficiency Therefore, finally of propeller assumed movi 𝐽�2𝜋𝐾 𝐾��the defined toveloci beto (20) 2014 𝑽 𝑨velocity equals to0 obtained computed as Edisi (Carlton, 1997) 𝜂= � (Carlton, (𝑛) = ℎ𝑟�=+ ℎ[1�− ] combining velocity to sh (9) obtained and𝜂and computed 1997) 𝑟�where cos(𝛿 2𝑛=− 1.)𝛿By 𝐽� 𝐾�as 𝑽 equals to 𝑽 defined to be (20) assumed movi = computed 𝑨 and the (1) 2𝜋𝐾 velocity to obtained and as (Carlton, 1997) �� 𝐾� 𝑽 equals to 𝑽 𝐽 assumed moving defined to (20) 𝑨 �� ( 𝜂 = ) ] (9) 𝑟� (𝑛) = 𝑟� + ℎ[1 −(�� cos 2𝑛 − 1 𝛿 2𝜋𝐾 The thrust and torque of propeller given in Eqs. defined 𝐽= 𝐾�𝐽of𝐾 � to be (20) �� ) assumed movi 𝑽 equals to 𝑽 𝜂 2𝜋𝐾 The thrust and torque propeller given in Eqs. 𝑨 defined to (20) � where ℎ = and 𝛿 = . By combining � � axial and tangential induced velocities with the Jurnal Teknik BKI =𝜂 = equals tomovi 𝑽 𝑺Sh . Table 2. assumed m (2) The and𝜂 can torque of propeller given in Eqs. 63 (14)thrust and (15) be 2𝜋𝐾 computed after obtaining the 𝑽 𝑨𝑽 �� assumed � 2. Shi equals 𝑽 2𝜋𝐾 (�� ) � 𝑨Table � (14) and be after obtaining the Edisi 03-Agustus assumed mt The thrust(15) andcan torque of (propeller given in 2016 Eqs. ) and (𝑉�the effective velocities in axial with Table 2.to Shi 2𝜋𝐾 𝑽 equals axialℎ and tangential induced velocities the �𝚪 ).after (14) and (15) can be computed computed obtaining the where = inflow and 𝛿 = . By combining 𝑨 The thrust and torque of propeller given in Eqs. According to Lee circulation distribution (2) 𝑽 𝑨Table equals 𝑽It 𝒎. According �� ) (�� ) (𝑉 2.to Shi � to Lee circulation distribution The thrust(15) and torque of((𝚪 in Eqs. 𝑽 𝑨 2. equals (14) and can be computed after given obtaining the 𝒎) tangential andcombining the IP ) and (𝑉�speed Ship � 𝛿directions effective inflow in rotational axialwith .after According to the Lee circulation distribution 𝚪propeller = and =velocities . By the (14) and (15) canon bethe computed obtaining Length over The thrust and torque of)may propeller given ininto Eqs. Table (1979), 𝚪𝒎 blade be resolved 𝒎 axial and tangential induced velocities the Table 2. Shi (2) where ℎ The thrust and torque of propeller given in Eqs. �� I Length over all (14) and (15) can be computed after obtaining the (1979), 𝚪 on the blade may be resolved into ) ( circulation𝒎 distribution 𝚪 . According to Lee of propeller (𝜔𝑟), the resultant of an inflow

8𝐾=� 𝜋𝐽��𝐾8𝐾 (16) � 0.000027174 0.0001 important 1.0000 Table 2. Another data are the the drag �� 𝜌𝑛 � 𝐷 � (16) 𝐶� = The 16𝐾 � (17) The main main input input data data inin PVL PVL are are the � = � 𝜋𝐽�� (17) 𝐶𝐶� == 𝐶16𝐾 ( ) 𝜋𝐽 coefficient 𝑪 , ratio between axial velocity and � nondimensionalized spanwise of 𝑫𝒗 � � 𝜋𝐽 The main main input input data data in PVL PVL arepropeller the 16𝐾 nondimensionalized spanwise of are propeller � (17) 𝜋𝐽�=��16𝐾 Jurnal Teknik BKI The in the � (17) 𝐶�finally ship velocity (𝑽 /𝑽 ) as well as ratio of tangential Therefore, the efficiency of propeller can be 𝑨 the 𝑺 represented by and nondimensionalized spanwise of between propellerthe 𝐶� = 𝜋𝐽�� where represented by 𝒓/𝑹 𝒓/𝑹 spanwise and the ratio ratio between the nondimensionalized of propeller where 𝜋𝐽� /𝑽 𝑪𝑫𝒗 is velocity to ship velocity (𝑽 obtained and computed as (Carlton, 1997) 𝑻 𝑺 ).asHere propeller chord length and diameter given 𝒄/𝑫 represented by 𝒓/𝑹 and the ratio between the 𝑇 (18) where propeller chord length and diameter given as 𝒄/𝑫 𝑇 represented by 𝒓/𝑹 and the ratio between the (18) where 𝐾𝐾� == � � 𝑇 𝐽� 𝐾� defined to be 0.008 and the inflow velocity is (20) propeller chord length andship diameter given as as 𝒄/𝑫 shown ininchord Table 1.1. The particular and other � 𝜌𝑛 �𝐷 𝜂�𝑇= (18) shown Tablelength The ship particular and other with propeller and diameter given 𝒄/𝑫 (18) 𝐾𝜌𝑛 =𝐷 � � � assumed moving only in horisontal direction shown inin Table Table in 1. The The ship ship particular particular and other other in 𝐾� 𝑄 = 𝜌𝑛� 𝐷�2𝜋𝐾� parameters used are (19) shown and parameters used 1. intocomputation computation are summarized summarized in 𝐷 (19) 𝐾𝐾� == �𝑄𝜌𝑛 𝑽 equals 𝑽 . 𝑄 parameters used in computation are summarized in 𝑨 𝑺 � (19) Table 2. Another important data are the drag � 𝜌𝑛 𝐷 𝑄 parameters used in computation are summarized in � � (19) Table 2. Another important data are the drag 𝐾𝜌𝑛 = 𝐷 Table 2.2. Another important data are velocity the drag dragand 𝐾��= 𝜌𝑛��𝐷�� The thrust and propeller given in coefficient Eqs. (Another , ,Ship ratio between axial Table important data are the 𝜌𝑛torque 𝐷 of of 𝑫𝒗 Table 2)):)2. Particulars and Other Parameters Therefore, finally the efficiency propeller can be ob((𝑪𝑪 coefficient ratio between axial velocity and 𝑫𝒗 coefficient 𝑪 , ratio between axial velocity and Table Ship Particulars and Other Parameters 𝑫𝒗),/𝑽 (14) andthe (15) can be computed after obtaining the (𝑪(𝑽 coefficient ratio between axial velocity and ship velocity ) as well as ratio of tangential Therefore, finally efficiency of propeller can be 𝑫𝒗 𝑨 𝑺 ship velocity (𝑽 /𝑽 ) as well as ratio of tangential tained and computed as (Carlton, 1997). Therefore, finallyfinally the efficiency of(propeller cancanbebeto Lee ship velocity velocity(𝑽 (𝑽𝑨𝑨/𝑽 /𝑽𝑺)𝑺) Item as wellas asratio ratio ofof tangential tangential Therefore, theefficiency efficiency Value )propeller . According circulation 𝚪of𝒎propeller ship Therefore, finally distribution the of can be velocity /𝑽 Here 𝑪𝑪𝑫𝒗 is toto ship (𝑽 𝑨 velocity 𝑺 as well obtained and computed as (Carlton, 1997) 𝑻/𝑽 𝑺 ).).Here /𝑽 Here velocity ship velocity (𝑽 obtained and computed as (Carlton, 1997) ). 𝑪 is is velocity to ship velocity (𝑽 obtained and computed as (Carlton, 1997) 𝑻 𝑺 𝑫𝒗 𝑻 𝑺 𝑫𝒗 130.29 Length over alland (Loa) (1979), 𝚪𝐽𝒎� 𝐾on the blade may be resolved defined into ). Herevelocity 𝑪 velocity to to be ship0.008 velocity (𝑽the obtained and computed as (Carlton, 1997) 𝑻 /𝑽𝑺inflow 𝑫𝒗 is (m) is (20) � defined Length to be 0.008 and the inflow velocity is (m) (20) It can defined to be 0.008 0.008 andperpendicular theinflow inflow velocity is (20) � 𝐾� � 𝐾�𝐽𝐽chordwise 𝜂𝜂== 𝜂𝐽and 125.37 between defined to and the velocity iswith (20) spanwise components. be � 𝐾� assumed moving only ininhorisontal horisontal direction 2𝜋𝐾 assumed moving only in direction with 𝜂2𝜋𝐾 ==�2𝜋𝐾� assumed moving only horisontal direction with moving only in horisontal direction with(m) � � 20.00 (Lbp) obtained by 2𝜋𝐾 solving the following simultaneous 𝑽𝑽assumed equals equalsto to𝑽 𝑽𝑺𝑺𝑺.... to 𝑽𝑨𝑽𝑨𝑨𝑨equals equals to 𝑽𝑽 13.70 (m) Breadth equation: 𝑺 (B) thrust and torque ofof propeller given inininEqs. The thrust andof torque propeller given inEqs. Eqs. � TheThe thrust and torque propeller given in Eqs. (14) and The thrust and torque propeller given 5.76 (m) Height (H) The thrust and torque ofof propeller given Eqs. Table2. 2.Ship ShipParticulars Particulars and Other Parameters Table Particulars and Other Parameters (14) and (15) can be computed after obtaining the (14) and (15) can be computed after obtaining the 2. Ship Particulars and Other Parameters Table 2. Ship and Other Parameters [ ( ) ( ) ( )] � 𝑢 � 𝑛, 𝑚 − 𝑢 � 𝑛, 𝑚 tan 𝛽 𝑛 Γ (15)(14) canand be(15) computed after the �circulation 19.6 (kn) Draught (T) (14) and (15) cancomputed be computed after the(21) Table can after obtaining the � be � obtaining � obtaining Item Value ). According (. 𝚪𝒎 Item Value Lee circulation distribution ((𝚪𝚪𝒎 )(to According totoΓtoto Lee circulation distribution Item Value Item Value �� ) . According Lee circulation distribution 𝚪 6700 (hp) Service speed (V ) ) S . According Lee circulation distribution distribution ( Γ ). According Lee (1979), on the 𝒎 𝒎 m𝚪 𝑉 m 130.29 (m) Lengthover overall all(Loa) (Loa) (1979), on the blade may be resolved resolved into Length ) tan 𝛽� (𝑛) 𝒎the (Loa) 130.29 (m) � (𝑛 (1979), 𝚪𝚪𝒎 on blade may be resolved into 130.29 (m) Length over all (1979), 𝚪 on the blade may be into 3.68 Delivered power (P ) D 𝒎 Length over all (Loa) 130.29 (m) (m) (1979), on the blade may be resolved into = � − 1� 𝑛 = 1, … 𝑀 blade may be into spanwise andIt chordwise 𝒎 resolved 125.37 (m) Length between between perpendicular perpendicular 125.37 spanwise and𝑉chordwise chordwise components. can be Length tan 𝛽(𝑛) 125.37 (m) perpendicular spanwise and chordwise components. ItIt Itcan be (m) Length between spanwise and components. can be � 5 (blades) Diameter of propeller (D) 125.37 Length between perpendicular spanwise and chordwise components. can be 20.00(m) (m) (m) (Lbp) obtained bybe solving the following following simultaneous components. It can obtained by solving the following(Lbp) 20.00 (Lbp) obtained by solving the simultaneous 20.00 (m) obtained by solving the following simultaneous 1.00 Number of propeller blade (Z) 20.00 (m) (Lbp) obtained by solving the following simultaneous 13.70(m) (m) Breadth(B) (B) equation: simultaneous equation: Breadth equation: 13.70 Breadth (B) equation: � 3. METHODS 32 Desired thrust coefficient13.70 (C T)(m)(m) 13.70 (m) Breadth (B) equation: 5.76 Height (H) � � (m)(m)12 Height(H) (H) 5.76 Height � Number of vortex panel 5.76 (M) � [𝑢�� (𝑛, 𝑚) − 𝑢�� (𝑛, 𝑚) tan 𝛽� (𝑛 )]Γ� 19.6 (kn) Draught (T) 5.76 (m) Height (H) (21) � 𝑢�Ship 𝑢�𝑚 tan𝑛𝛽)]� (Γ𝑛 )]Γ� 19.6 (kn) Draught(T) (T) � (𝑛, 𝑚)(− � (𝑛, 𝑚)𝛽 (21) ((𝑛,𝑛,[𝑚 � 19.6 (kn) Draught (21) Number [�𝑢�� [𝑢 6700 (hp) Servicespeed speed (VS)of ) input radii 6700 𝑚))−−𝑢�and 𝑢�� (𝑛,𝑛,Propeller 𝑚))tan tan 𝛽� (� (Data 𝑛 )]Γ�� 19.6 (kn) Draught (T) (21) �� (hp) Service (V S In 𝑉order compute by 𝑉�((𝑛))totan 𝛽� (𝑛) the performance of propeller �� 6700 (hp) Service speed (V ) S 3.68 (m) Delivered power (P ) 𝑛 tan 𝛽 (𝑛) D �� = � 𝛽�(𝑛) � − 1� 𝑛 = 1, … 𝑀 6700 Service speed (V(P S)D) 3.68 (m) (hp) Delivered power 𝑉�(𝑛 =) tan − 1� 𝑛 = 1, … 𝑀 lattice (PVL) employing vortex 𝑉� �𝛽� �tan 𝛽(𝑛)propeller (𝑛)the 3.68 (m) Delivered power (P 5(blades) (blades) Diameter of propeller 4.Numerical NUMERICAL RESULTS AND D))(D) tan 𝛽(𝑛) == 𝑉�(𝑛 )��𝑉tan −−1� 𝑛𝑛==1,1,……𝑀 4. And Discussions 3.68 (m) Delivered power (P � D(D)Results 5 Diameter of propeller 1� 𝑀 the following propeller data are required 𝑉𝑉�program, tan 𝛽(𝑛) 1.00 Number of propeller blade (Z) 5 (blades) DISCUSSIONS Diameter of propeller (D) tan 𝛽(𝑛) � 1.00 Number ofofpropeller blade 5 (blades) Diameter propeller (D)(Z) METHODS as for the input data. 32 Desiredof thrust coefficient (C(Z) T) 1.00 Number propeller blade 3.3. METHODS 32 Desired thrust coefficient (C ) T(Z) 1.00 Number of propeller blade Figure of 2 shows the computation 12 result of circulation distriNumber vortex panel (M) Desired thrust coefficient (C T)) 1232 METHODS Number of vortex panel (M) 3. 3.3. METHODS Ship and Propeller Data 32 Desired thrust coefficient (C T Ship and Propeller Data Number ofstrength inputradii radii bution obtained by solving simultaneous equaShip and Propeller Data 12 Number of vortex panel (M) Number of input 12 Number of vortex panel (M) In order to compute the performance of propeller by In order to compute the performance of propeller by Ship and Propeller Data tion given in Eq.(21) for several propeller revolutions. From ofofinput solving simultaneous equation given in Eq. Ship and Propeller Data employing thethe propeller vortex lattice lattice (PVL) byNumber Number inputradii radii In In order toto compute performance of propeller 4. NUMERICAL NUMERICAL RESULTS AND revolutions. From this fig employing the propeller vortex (PVL) compute the performance of propeller by several propeller Figure 2 shows the computation result of 4. RESULTS AND this figure, we could clearly observe that the circulation Inorder order to compute the performance of propeller by program, the following following propeller data are are requiredthe DISCUSSIONS program, the data required employing the the propeller vortexpropeller lattice lattice (PVL) program, could clearly observe that circulation distribution strength obtained by employing propeller vortex (PVL) DISCUSSIONS as for the input data. employing the propeller vortex lattice (PVL) 4.4. NUMERICAL RESULTS AND distribution strengthasincrerases asrevolution the propeller revolution NUMERICAL RESULTS AND as for the input data. circulation distribution strength increrases the propeller decreases. following propeller data are required as for the input data. program, program, the the following following propeller propeller data data are are required required DISCUSSIONS decreases. DISCUSSIONS


0.08

0.06

/2RV

as asfor forthe theinput inputdata. data. Table Propeller Input InputData Data Table11.: Propeller 𝒄 water and r/R c 𝑫 tegrating 0.199728261 0.735 0.1848 g up over 0.205434783 0.756 0.2000 the total 0.222826087 0.820 0.2500 0.241304348 0.888 0.3000 (14) 𝑟 0.267934783 0.986 0.4000 0.290217391 1.068 0.5000 (15) 𝑑𝑟 0.304619565 1.121 0.6000 0.306521739 1.128 0.7000 0.289402174 1.065 0.8000 may be 0.238586957 0.878 0.9000 advance 0.184782609 0.680 0.9500 0.000027174 0.0001 1.0000 (16) (13)

n= 2.1rps n= 3.5rps n= 5.0rps n= 7.0rps

0.04

0.02

0.00 The main input data in PVL are the 0.2 0.4 0.6 0.8 1.0 The main input data in PVL are the nondimensionalized nondimensionalized spanwise of propeller r/R spanwise of propeller by r/R and the the rarepresented by 𝒓/𝑹represented and the ratio between 2 : Strength of Circulation Distribution alongwithout Hub E Figure 2. StrengthFigure of Circulation Distribution along Radius of 5 Bladed Propeller tio between chord length and propeller the chordpropeller length and diameter given as diameter 𝒄/𝑫 Radius of 5 Bladed Propeller without Hub Effect. (18) 0.8 in shown Table 1. particular and other and givenshown as c/D in The Tableship 1. The ship particular parameters used in computation are summarized in (19) other parameters used in computation are summarized in Needless to say that in this figure the effect of the presAnother important important data drag drag ence of propeller hub is not taken into account in TableTable 2. 2. Another data arearethe the coefficient (𝑪𝑫𝒗 ), ratio between axial velocity and the circulation distribution. It means that coefficient (CDv ), ratio between axial velocity and ship velocity computing 0.6 ship velocity (𝑽𝑨/𝑽𝑺 ) as well as ratio of tangential er can be the blades are assumed to have a free tip at both ends. (VA / V ) as well as ratio of tangential velocity to ship velocity S velocity to ship velocity (𝑽𝑻 /𝑽𝑺 ). Here 𝑪𝑫𝒗 is (VT / defined VS). HeretoCDvbeis 0.008 defined to be andvelocity the inflow and the0.008 inflow is ve- Consequently the circulation becomes zero at blades ends, (20) moving only only in horisontal direction with with both locityassumed is assumed moving in horisontal direction 0.4at the hub and the tip. By judging from Figure 2, one 𝑽 equals to 𝑽 . KT spesicfications 𝑨 may envisage that a propeller with the VA equals to VS . 𝑺 KQ Jurnal Teknik BKI n in Eqs. Edisi 02 Desember 2014 Table 2. Ship Particulars and Other Parameters ining the 0.2 Item Value g to Lee Jurnal Teknik BKI 130.29 (m) ved into 64 Length over all (Loa) Edisi 03-Agustus 2016 Length between perpendicular 125.37 (m) t can be 20.00 (m) (Lbp) ultaneous 0.0

K T, K Q

(17)

Technical Journal of Classification and3. Independent Assurance Figure Propeller Thrust and Torque

0.02

0.8

0.00

K T, K Q



given 0.2 in Table 2, when running will have Propeller with blade number 3, 4 and 6 reach its maximum 0.4 0.6at slow speed, 0.8 1.0 0.7 r/R running in high speed. efficiency; η=0.6788, η=0.6813, η=0.6785 at propeller larger propeller forces than one ure 2. Strength Circulation Distribution Radius 3 of given 5 Bladed Hub Effect 4.0 rps, 3.6 rps, 3.1 rps, respectively. The Thisofcan be seen obviouslyalong in Figure asPropeller follows.without rotation 0.6 maximum efficiency of all propellers is almost the same with 0.8 different rotation. Based on this result, it can be said that the 0.5 maximum propeller efficiency shifts to higher rotation Z = 3 blades Z = 4 decreases. blades as the number of propeller blades It means 0.6 Z = 5 blades 0.4 that the slow speed propellers should have more blades Z = 6 blades compared to that of the high speed propeller in order 0.3 to get the optimum efficiency. Different with Figure 4, 0.4 Figure 5 presents the consequence of modifying the radius of KT 0.2 KQ propeller to its efficiency. It in Figure 2.0 3.0 4.0is observable 5.0 6.0 5 that the 7.0 n (rps) efficiency of propeller with 5 blades reduces as its diameter Figure 4. Propeller Efficiency with Blade Variation at Several Propeller Rota 0.2 decreases for slow rotation and vice versa for high rotation. 0.8

0.0 2.0

3.0

4.0

n (rps)

5.0

6.0

0.7

7.0

Figure 3 : Propeller Thrust and Torque Althought this propeller has a high thrust and torque at slow speed, it does not necessarily means that it will get high efficiency at that speed. The efficiency of propeller is depicted in Figure 4 for several revolutions. It can be seen from this figure that the propeller efficiency has its highest value at certain rotation. Here we could observe that the maximum efficiency of propeller under consideration (5 blades) is obtained at n=3.5 rps with η=0.6797, Figure 3. Propeller Thrust and Torque not at n=2.1 rps where the propeller forces become large. 0.8

0.7



0.6

0.5 Z= Z= Z= Z=

0.4

3 blades 4 blades 5 blades 6 blades

0.3

0.2 2.0

3.0

4.0

n (rps)

5.0

6.0

7.0



0.6

0.5 Dp = Dp = Dp = Dp =

0.4

3.00 m 3.25 m 3.68 m 3.84 m

0.3

0.2 2.0

3.0

4.0

n (rps)

5.0

6.0

7.0

5. Propeller Efficiency with with Diameter Variation at Several Figure Figure 5 : Propeller Efficiency Diameter Variation at Propeller Ro Several Looking to the both Figs. 4 andPropeller 5, it can be Rotations understood that a propeller with the high nu

Looking to the both Figs. 4 and 5, it can be understood that a propeller with the high number of blade has higher efficiency than the low number at slow rotation and a propeller with the small diameter has higher efficiency than the large one at high rotation as already previously described. By combining these two considerations, one may get a propeller with high efficiency for a wider range of rotation. Therefore running a propeller at its optimum rotation with suitable number of blade and size of diameter would optimize its performance and hence it may reduce the fuel consumption used during voyage.

4. Propeller Efficiency with Variation at Several UpRotations to this point, the effect of presence of the hub to FigureFigure 4 : Propeller Efficiency withBlade Blade Variation at Propeller Several Propeller Rotations the propeller efficiency has not been explored. Figure 6 0.8 represents the strength of circulation distribution as in It is0.7also shown in the same figure the effect of changing Figure 2 with the effect of hub is taken into account. From the number of propeller blades to the propeller efficiency. this figure, it is clearly shown that the presence of the Jurnal Teknik BKI Edisi 02- Desember 2014



0.6

0.5

0.4

Dp = 3.00 m Dp = 3.25 m Dp = 3.68 m


65

Jurnal Teknik BKI

PROPULSION PROPULSION propeller hub increases the strength of circulation, especially around the propeller hub radius. Although the circulation strength increases, the efficiency of propeller decreases as depicted in Figure 7. It is also observed that as the number of blade reduces, the discrepancy of propeller efficiency between the propeller with and without hub increases particularly for slow rotation. Nevertheless the discrepancy between them be0.08 0.08

5.

as

the

speed

of

propeller

Conclusions

From this study, it may be concluded that a propeller with less number of blades and small in diameter is recommended to be operated at middle to higher rotation and vice versa in order to acquire the highest efficiency. Another conclusion is that the effect of propeller hub increases the strength of circulation distribution, especially around the propeller hub radius. However, it slightly reduces the efficiency of propeller particularly at slow rotation and becomes negligible as the propeller rotation increases.

Acknowledgement

/2RV /2RV

0.06 0.06

n= 2.1rps n= n=3.5rps 2.1rps n= n=5.0rps 3.5rps n= n=7.0rps 5.0rps n= 7.0rps

comes negligible rotation increases.

0.04 0.04

Foundation item: Supported by PT. Biro Klasifikasi Indonesia.

References

0.02 0.02



Carlton, J., (1997). Marine Propellers and Propulsion. Text book, Massachusetts Institutes of Technology, Cam0.00 bridge. 0.4 0.6 0.8 1.0 0.000.2 0.2 0.4 0.6 0.8 1.0 Dannecker, J.D., (1997). A Numerical Study of Fluid Flow r/R r/R Around Two-Dimensional Lifting Surfaces. MasFigure 6 6. : Strength Circulation Distribution along Figure Strength ofof Circulation Distribution along Radius of 5RadiBladed Propeller with Hub Effect Figureus 6. Strength of Circulation Distribution along Radius of 5 Bladed Propeller with Hub Effect ter thesis, Massachusetts Institutes of Technology, of 5 Bladed Propeller with Hub Effect 0.8 Cambridge. 0.8 Flood, K.M., (2009). Propeller Performance Analysis Using Lifting Line Theory. Master thesis, Massachusetts In0.7 0.7 stitutes of Technology, Cambridge. Hunt, D.S., (2001). Propeller Blade Design Thickness and 0.6 Blockage Issues Due to Source-Induced Factors. Mas0.6 ter thesis, Massachusetts Institutes of Technology, 0.5 Cambridge. 0.5 Z = 3 blades w/o hub Kerwin, J.E. (1986). Marine Propellers. Annual Review of FluZZ==33blades hub bladesw/ w/o hub id Mechanics. 0.4 ZZ==53blades bladesw/o w/ hub ZZ==55blades w/ hub 0.4 Kerwin, J.E. (2001). Hyrofoils and Propellers. Lecture notes. blades w/o hub Z = 5 blades w/ hub Massachusetts Institutes of Technology, Cambridge. 0.3 Lee, C.S., (1970). Prediction of Steady and Unsteady Perfor0.3 mance of Marine Propellers With or Without Cavita0.2 tion by Numerical Lifting-Surface Theory. Ph.D. thesis, 2.0 3.0 4.0 5.0 6.0 7.0 0.2 Massachusetts Institutes of Technology, Cambridge. 2.0 3.0 4.0 n (rps) 5.0 6.0 7.0 n (rps) Mahmuddin, Figure 7. Effect of The Presence of The Propeller Hub to Propeller Efficiency F., (2013). Optimum Propeller Rotation AnalyFigure 7. Effect of The Presence of The Propeller Hub to Propeller Efficiency sis Based on the Lifting Line Theory. Jurnal Riset dan Figure 7 : Effect of The Presence of The Propeller Hub to 5. CONCLUSIONS Teknologi Kelautan, Vol. 11 No. 2. 5. CONCLUSIONS Propeller Efficiency

Muhdar Tasrief, adalah personil Divisi Riset dan Pengembangan PT. Biro Klasifikasi Indonesia (Persero). Pada awal tahun 2006 penulis menyelesaikan pendidikan Sarjana Jurnal Teknik BKI Teknik diEdisi jurusan Teknik 2014 Perkapalan Universitas Hasanud02 - Desember din dan bergabung dengan BKI pada akhir tahun 2006. Ta-

66


hun 2009, penulis berkesempatan melanjutkan pendidikan ke jenjang yang lebih tinggi. Faisal Mahmuddin, Staf Pengajar Jurusan Teknik Sistem Perkapalan - Fakultas Teknik, Universitas Hasanuddin Indonesia

NOVEL DESIGN OF HIGH LOAD CAPACITY SMART MAGNETORHEOLOGICAL ELASTOMER VIBRATION ISOLATOR IN HYBRID MODE Hardika Ratditya Ardyanto

Abstract This experimental study was a further research of Magnetorheological Elastomer (MRE) utilization in order to isolating ship structural borne vibration in semi active manner. MRE have been widely used as vibration isolator and vibration absorber since 1950, because this smart material have taken many researcher interest. Their durability and easy-to-manipulate characteristic combine with relatively low production cost have been considered as feasible material used to actively attenuate excessive or unwanted vibration from ship structure. This study aim was to design high strength novel active vibration isolator which is combined the arrangement of MRE for both squeeze (horizontal) and shear (vertical) that also known as hybrid mode. This arrangement variation will be compared with each single arrangement mode, and suitable control algorithm will be designed using Skyhook Control and implemented in order to having high isolation of vibration in single degree of freedom (SDOF). Keywords : Magnetorheological Elastomer, Hybrid Mode, Skyhook control, Vibration Isolator, SDOF

1.

Introduction

A

ttenuating vibration has become major topics in the development of marine vessel technology. In marine application, the vibration source mainly come from main engine or generator. Thus problems requires a system consist of several vibration isolator or absorber which is used to reduce the vibration effects to the structure. The unwanted vibration are really hard to predict and calculate in the initial design stages, which made the selection of traditional isolation might not be always appropriate in any situation to overcome all condition that might happen along ship operation. Therefore researchers are developing means to actively control vibration which can operate automatically according toset input parameter, in order to facing wide range of possible situation. In terms of naval ship engineering, the automatic tuned isolator will work on stealth operation favor. The isolation of vibration coming from high vibrating source such as propulsion engine will also reducing the structural borne noise and eliminating underwater noise signature in results. The ship industries nowadays are tends to utilize the system which having less energy consumables, having low

Jurnal Teknik BKI

PROPULSION

price and only occupied tiny space. Therefore the method such as active vibration which using hydraulic force will require huge amount of space and also emanates another source of noise which is coming from hydraulic fluid distribution line. With the influence of technology improvement nowadays, those needs can be satisfied with the utilization of smart material. In general, smart material are all materials that having changeable mechanical properties and/ or dimensional shape, with the aid of controlled external force. Among various type of smart material which is developed recently to control mechanical vibration up until now, magnetorheological materials was chosen due to its flexibility, low energy demand and low manufacturing cost (Torre, 2009). This material can exist in form of Elastomer or Fluids. The elastomer form had several advantages compare to the fluid forms such as have no special storage requirement to prevent contamination, no need to store the material in tight compartment to avoid leakage, capable to withstand more loads, etc. Hence, the latest research have found two ways to utilize the MRE, which is shear and squeeze mode. Both of this two methods have its own advantages. In order to have wide range of isolation frequency bandwidth, researcher tends to use MRE in shear mode but on the other hand if

67


Jurnal Teknik BKI


Jurnal Teknik BKI

PROPULSION

Figure 1. Magnetorheological M Figure 1. Magneto

PROPULSION

Figure 1. Magnetorheologica

𝑚𝑥̈ + 𝑐𝑥̇ + 𝑘𝑥 = 𝐹(𝑡) (2-1)

+ 𝑘𝑥 = 𝐹(𝑡) (2-1) 𝑚𝑥̈ + 𝑐𝑥̇ +𝑚𝑥̈ 𝑘𝑥+=𝑐𝑥̇𝐹(𝑡) (2-1)

While the external forces is avector it could

Figure 2

theforces external forces is avector it could Figu While the While external is avector it could

be taken in phasor form given that 𝐹(𝑡 ) = 𝐹𝑒 �� Platform be taken in phasor form given that

be taken in phasor form given that

𝐹(𝑡) = 𝐹(𝑆𝑖𝑛𝜔𝑡 + 𝑖𝐶𝑜𝑠𝜔𝑡) = 𝐹𝑒 �� (2-2)

𝐹 (𝑡 ) =

𝐹(𝑡) =+𝐹(𝑆𝑖𝑛𝜔𝑡 = 𝐹𝑒 �� (2-2) 𝐹(𝑡) = 𝐹(𝑆𝑖𝑛𝜔𝑡 𝑖𝐶𝑜𝑠𝜔𝑡)+=𝑖𝐶𝑜𝑠𝜔𝑡) 𝐹𝑒 �� (2-2)

Though for engine vibration case, the mass

𝐹� (𝑡 ) = 𝐹� 𝑒

engine case, vibration case, the𝐹mass Though forThough enginefor vibration the mass � (𝑡 ) =

should translated atvertical direction only.

should atvertical translated direction atverticalonly. direction only. should translated time. 𝐹� = 𝑐 �� 𝐹 � = (2-3) 𝐹� 𝑆𝑖𝑛𝜔𝑡 (2-3)time. 𝐹� = 𝑅𝑒�𝐹 (𝑡) = (2-11) = 𝐹��𝑒𝑆𝑖𝑛𝜔𝑡 𝑅𝑒�𝐹 �� (𝑡) �𝑒 of𝐹�� equation such�that:

𝐹�� (𝑡) = 𝑅𝑒�𝐹� 𝑒 �� = 𝐹� 𝑆𝑖𝑛𝜔𝑡 (2-3)

a

equation that: equationof(2-11) such(2-11) that: such(2-4) 𝐹of � = 𝑐𝑥̇ + 𝑘𝑥

𝑐𝑥̇ + 𝑘𝑥 of transmitted 𝑘𝑥 (2-4) 𝐹� = 𝑐𝑥̇ +𝐹the � = Therefore, bmagnitude

(2-4) (2-6)

(−𝑚

Figure 1. Magnetorheological Materials the magnitude of transmitted (2-6) force can Therefore, bethedetermined byof following Therefore, magnitude transmitted Figure 1 : Magnetorheological Materials

(

applied, equ force can be determined by following equation, viz.: force can be determined by following

𝑚𝑥̈ objective + 𝑐𝑥̇ + 𝑘𝑥 𝐹(𝑡) (2-1)design, MRE Therefore, the magnitude of transmitted force can be dethe strength is main for=the system � +equation, | =following |equation, applied, 𝑥̇equation, 𝑘 � 𝑥 �viz.: (2-5) 𝐹𝑻by squeeze mode better in that favor (Popp, 2009). termined viz.: √𝑐 �viz.: Figure 2. Forced Vibration Diagram While will the works external forces is avector it could Many MRE research nowadays have been conducted in or(𝑖𝜔 �+𝑘 � diagram of applied force its� 𝑥transmitted �| 𝑥̇ �|+ � 𝑥��𝑥̇ and (2-5) |𝐹�� (2-5) 𝑻 =𝑘√𝑐 ) = 𝐹𝑒 be taken in phasor form given that system. 𝑻 | = √𝑐 𝐹 𝐹(Platform 𝑡Platform der to achieve those two advantages in single Platform Platform 𝐹(𝑡) = 𝐹(𝑆𝑖𝑛𝜔𝑡 + 𝑖𝐶𝑜𝑠𝜔𝑡) = 𝐹𝑒 �� (2-2)

2.

Research Basic Theory

2.1.

should translated atvertical direction only. SDOF Vibration

Though for engine vibration case, the mass 𝐹�� (𝑡) = 𝑅𝑒�𝐹� 𝑒

��

� = 𝐹� 𝑆𝑖𝑛𝜔𝑡 (2-3)

force along SDOF forced vibration will be

(2-7)

of applied force and its transmitted diagram ofdiagram applied force and transmitted The diagram of applied force and itsits transmitted force illustrated atforce Figure 2.1.: Platform along SDOF forced vibration will be illustrated at Figure : (2-7) along SDOF forced will vibration be ∅) SDOF force�(�� along forced vibration be 2will

𝐹� (𝑡 ) = 𝐹� 𝑒 but in the same at Figure 2.1.: illustrated illustrated at Figure 2.1.: Platform time. 𝐹� = 𝑐𝑥̇ + 𝑘𝑥 .

Regards to the actual rotating machine, the applied exciof equation (2-11) that: tation force will not be zero.such Many excitation force source could be𝐹appear, such as unbalanced rotation, dynamic (−𝑚𝜔� + 𝑖𝜔𝑐 + 𝑘 )𝑋 = 𝐹 (2-4) � = 𝑐𝑥̇ + 𝑘𝑥 forces of the bearing location due to loose component, (2-6) magnitude of transmitted Figure Figure 1.1.Magnetorheological Magnetorheological Materials Materials etc. The Therefore, equation of the a damped SDOF external Figure 1. with Magnetorheological Figure exci1. Magnetorheological Materials Materials tation force can be given with following equation: force can be determined by following

𝑚𝑥̈ 𝑚𝑥̈++𝑐𝑥̇𝑐𝑥̇++𝑘𝑥𝑘𝑥==𝐹(𝑡) 𝐹(𝑡)(2-1) (2-1) 1. Magnetorheological Materials 𝑚𝑥̈ + 𝑐𝑥̇ + 𝑘𝑥 =𝑚𝑥̈ 𝐹(𝑡) + 𝑐𝑥̇ (2-1) +Figure 𝑘𝑥 = 𝐹(𝑡) (2-1) applied, equation will change into: equation, viz.: Figure(2-3) 2 : Forced Vibration Diagram Figure Figure 2. 2. Forced Forced Vibration Vibration Diagram Diagram While While the the external external forces forces is is avector avector it it could could While forces isisexternal itit could takenFigure Vibration 2. Forced Diagram Vibration Diagram While the the|𝐹external external While forces could is be avector itincould2. ForcedFigure �forces � the �avector � +𝑘 𝑥avector (2-5) 𝑻 | = √𝑐 𝑚𝑥̈ 𝑥̇+ 𝑐𝑥̇ + 𝑘𝑥 = 𝐹(𝑡) (2-1) �� force will be distributed through ship phasor form given ()𝑡 )=transmitted bebetaken takeninthat inphasor phasorform formgiven giventhat that 𝐹(The 𝐹𝑡�� =𝐹𝑒𝐹𝑒 �� ∅ (Materials be taken in phasor beof form taken given in phasor that and form given that𝐹(𝑡 ) = 𝐹𝑒 𝐹(𝑖𝜔𝑐 𝑡 )and =+𝐹𝑒 𝑒 𝑘)𝑋 = 𝐹 diagram applied force its transmitted � Figure 1. Magnetorheological structures hull, and generates vibration on ship’s Figure 2. Forced Vibration Diagram While the external forces is avector it could �� (2-2) (2-2) 𝐹(𝑡) 𝐹(𝑡)==𝐹(𝑆𝑖𝑛𝜔𝑡 𝐹(𝑆𝑖𝑛𝜔𝑡++𝑖𝐶𝑜𝑠𝜔𝑡) 𝑖𝐶𝑜𝑠𝜔𝑡) 𝐹𝑒𝐹𝑒 ��== �� structure which in further will become the source of struc(2-2) = 𝐹(𝑡) = 𝐹(𝑆𝑖𝑛𝜔𝑡 𝐹(𝑡) + 𝑖𝐶𝑜𝑠𝜔𝑡) = 𝐹(𝑆𝑖𝑛𝜔𝑡 = 𝐹𝑒+ vibration 𝑖𝐶𝑜𝑠𝜔𝑡) 𝐹𝑒be (2-2) force along SDOF forced will (𝑡 ) = 𝐹𝑒 ��(�� be taken in phasor that 𝐹(2-7) �(�� ∅)∅) 𝑚𝑥̈ + 𝑐𝑥̇ +form 𝑘𝑥vibration =given 𝐹(𝑡) (2-1) Though Though for for engine engine vibration case, case, the themass mass 𝐹(�𝑡()�(�� but but inin the the same same 𝑡 )= =𝐹∅) Though for engine vibration case, the mass should trans- 𝐹�tural borne noise. To avoid any damage of hull vibration �𝐹𝑒� 𝑒 ∅) Though illustrated for engine Though vibration for engine case, the vibration mass case, the mass ( ) ( ) 𝐹 𝐹 𝑒 but in the 𝑒 �(�� same but in the same 𝑡 = 𝐹 𝑡 = 𝐹 �� at Figure 2.1.: � � � � 𝐹(𝑡) =the 𝐹(𝑆𝑖𝑛𝜔𝑡 + forces 𝑖𝐶𝑜𝑠𝜔𝑡) = 𝐹𝑒 lated atvertical direction only. Assuming the force is har- that emanates from Vibration engine as Diagram a main source of vibration Figure 2. Forced While external isdirection avector it (2-2) could should should translated translated atvertical atvertical direction only. only. shouldmotion translated should atvertical translated direction atvertical only. direction only. in concern, Forced �(�� Vibration system can one be ofthe following monic (i.e. uniform sine wave), then the input exwe should applied either ∅) Though for engine�� vibration case, the mass 𝐹�((𝑡𝑡))==𝐹𝑒 𝑒 but in the same 𝐹�� be taken in phasor form given that 𝐹 (𝑡) (𝑡) time. time. 𝐹 𝐹 = = 𝑐𝑥̇ 𝑐𝑥̇ + + 𝑘𝑥 𝑘𝑥 . . 𝐹 𝐹 𝑒 𝑒 � = � = 𝐹 𝐹 𝑆𝑖𝑛𝜔𝑡 𝑆𝑖𝑛𝜔𝑡 (2-3) (2-3) = = 𝑅𝑒�𝐹 𝑅𝑒�𝐹 � �that can minimize vibration effect on hull ,viz. : �� is the�� of F(t) that � � can be written as : citation real �� solution (𝑡) time. time. 𝐹� = 𝑐𝑥̇ + 𝑘𝑥 . 𝑐𝑥̇given + 𝑘𝑥as. follow: 𝐹�� (𝑡) force 𝑒�� =part � = 𝐹� 𝑆𝑖𝑛𝜔𝑡 (2-3)𝐹� = = 𝑅𝑒�𝐹 =𝐹 𝑅𝑒�𝐹 �𝐹 � 𝑆𝑖𝑛𝜔𝑡 � 𝑒 (2-3) should translated atvertical direction ��only. 1. Isolates the vibration sources (2-2) 𝐹(𝑡) = 𝐹(𝑆𝑖𝑛𝜔𝑡 +such 𝑖𝐶𝑜𝑠𝜔𝑡) ofofequation equation (2-11) (2-11) suchthat: that:= 𝐹𝑒 𝜔 � vibration energy of equation (2-11) of 𝑅𝑒�𝐹 such equation that: ��(2-11) such that: 2. Applying means ) (2క 𝜔 the (𝑡) = (2-3) time. 𝐹� = 𝑐𝑥̇ 𝐹 � = 𝐹� 𝑆𝑖𝑛𝜔𝑡 (2-3) �(�� ∅) .1to+‘absorb’ � 𝑒 vibration �+ � 𝑘𝑥 𝐹 Though for engine case, the mass ( ) 𝐹 𝑒 but in the same 𝑡 = 𝐹 ( ( ) ) � −𝑚𝜔 −𝑚𝜔 + + 𝑖𝜔𝑐 𝑖𝜔𝑐 + + 𝑘 𝑘 𝑋 𝑋 = = = = 𝑐𝑥̇ 𝑐𝑥̇ + + 𝑘𝑥 𝑘𝑥 (2-4) (2-4) 𝐹�� 𝐹 �𝐹 𝐹 � � �� 3. Repair unbalance rotating equipment 𝑖𝜔𝑐�+(−𝑚𝜔 𝑘 )𝑋 = + 𝐹 𝑖𝜔𝑐 + 𝑘 )𝑋𝜔= 𝐹 (2-4) (2-4)(−𝑚𝜔� 𝐹+� = 𝐹� = 𝑐𝑥̇ + 𝑘𝑥 𝐹� = 𝑐𝑥̇ + 𝑘𝑥 𝜔 � ofexternal equation (2-11)atvertical such that:directioninto translated only. While theshould excitation force introduced the sys- (2-6) (2-6) (1 − �𝜔 � )� + (2క 𝜔 )� Therefore, Therefore, the the magnitude magnitude ofof transmitted transmitted (2-6) (2-6) � � Therefore, the Therefore, magnitude the of transmitted magnitude of transmitted (−𝑚𝜔� of tem, there will be + a force transmitted as force(2-4) received by The isolation + 𝑖𝜔𝑐 + 𝑘 )𝑋idea = 𝐹was chosen with considvibration =(𝑡) 𝑐𝑥̇ 𝑘𝑥 𝐹 �� force 𝐹 � = 𝐹� 𝑆𝑖𝑛𝜔𝑡 =can 𝑅𝑒�𝐹 force can bebe� 𝑒determined determined byby (2-3) following following time. 𝐹� = 𝑐𝑥̇ + 𝑘𝑥 . �� force can foundation be force determined can isbeabyfraction determined following by following the system which of equation such eration of application for such technique in hostile and (2-6) Therefore, the magnitude applied, applied, equation equation(2-3) (2-3)like will will change changeinto: into: of equation (2-11) such that: of transmitted equation, equation, viz.: viz.: that: less spacious the room.into: If the absorpapplied, equation applied, (2-3) location will equation change(2-3) into:engine will change equation, viz.: equation, viz.: force can � �be determined by following tion technique applied �+ (−𝑚𝜔� +is𝑖𝜔𝑐 + 𝑘 )𝑋using = 𝐹 vibration absorber, the =|𝑻�= + 𝑘𝑥��𝑥̇ + (2-4)(2-4) 𝐹|�𝐹|�𝑻𝐹 |𝑐𝑥̇=√𝑐 𝑘 ��𝑘𝑥��𝑥 � (2-5) (2-5) √𝑐 � 𝑥̇ �𝑥 � | |𝐹𝑻 | = √𝑐 | 𝑥̇ + 𝑘 𝑥 (2-5) 𝑥̇ + 𝑘 (2-5) = 𝐹 √𝑐 risk of injury and other impact damage 𝑻 applied, equation (2-3) will change into: will raised due equation, viz.: (𝑖𝜔𝑐 (𝑖𝜔𝑐++𝑘)𝑋 𝑒 ��∅ ��∅ 𝑘)𝑋 ==𝐹�𝐹𝑒��∅ Therefore, the magnitude ofitsitstransmitted Jurnal Teknik BKI diagram diagram ofofapplied applied force forceand and transmitted (2-6) ��∅ (𝑖𝜔𝑐 + 𝑘)𝑋 = 𝐹(𝑖𝜔𝑐 + 𝑘)𝑋 = 𝐹� 𝑒 diagramEdisi of applied diagram of and force and its transmitted �𝑒 2014 � 𝑥̇force �+ � 𝑥applied �its transmitted | =- Desember |𝐹𝑻02 𝑘 (2-5) √𝑐 can determined by following (2-7) force forcealong alongbe SDOF SDOF forced forcedvibration vibration will will(2-7) bebe (2-7) (2-7) force along SDOF force forced alongvibration SDOF forced will bevibration will be ��∅ (𝑖𝜔𝑐 + 𝑘)𝑋 𝐹� 𝑒change Jurnal Teknik BKI diagram of applied force and its transmitted 68 applied, equation (2-3)=will into: equation, viz.: illustrated illustrated at at Figure Figure 2.1.: 2.1.: 03-Agustus illustratedEdisi at Figure illustrated 2.1.:2016at Figure 2.1.: (2-7)Forced force SDOF forced vibration will be Forced Vibration Vibration system system can can bebe |𝐹𝑻 | =along (2-5) √𝑐 � 𝑥̇ � + 𝑘 � 𝑥 � Forced Vibration Forced system Vibration can besystem can be

Forced

given a

For

𝐹� giv � �= 𝐹

𝐹� � 𝐹

o

To deduce how much force transmitted magnetorheological effectmaterial (MR effect).structure ofMaterials the system. MR and acceleration as Figure 1. Magnetorheological

velocity

to the ground from external excitation MR effect can be calculated by finding agnetorheological Materials torheological Materials 𝑚𝑥̈ +displacement 𝑐𝑥̇ + 𝑘𝑥 𝐹(𝑡) (2-1) generally consists and of non-magnetic ivation from function. Figure 1. Magnetorheological Materials force, we=can find out the ratio between Technical the Journal of Classification percentage increment ofIndependent mechanical Assurance Figure 2. Forced Vibration Diagram While the external forces is avector it could netorheological Materials transmitted force to external material rubber or solidthose displacement, velocity andexcitation polymer properties (can be (i.e. taken as changing 𝑚𝑥̈ + 𝑐𝑥̇ + 𝑘𝑥 = 𝐹(𝑡) (2-1) �� ( ) taken in Forced phasor form given that Figure 2.force Forced Vibration Diagram 𝐹 𝑡 = 𝐹𝑒 Figure 2. Vibration Diagram ould be or iswell known as vibration value Vibration of stiffness) Figure 2. Forced Diagrambetween zero While the external forces avector it could �� like matrix in case of elastomer) as base eleration at equation (2-1) to gain: �� )==𝐹(𝑆𝑖𝑛𝜔𝑡 (2-2) + 𝑖𝐶𝑜𝑠𝜔𝑡) = 𝐹𝑒 )to 𝐹=(𝑡having 𝐹𝑒secondary 𝐹(𝑡𝐹(𝑡) 𝐹𝑒 mass as part absorber �� finding the percentage increment ofachieved mechanical properTransmissibility. Theof vibration transmissibility magnetic field and maximum ( ) be taken in phasor form given that Figure 2. Forced Vibration Diagram 𝐹 𝑡 = 𝐹𝑒 ld ∅) be taken as changing value of stiffness) between moving�for at high frequency. It has been in the (can Though engine vibration case, the shown masssystem -2) (−𝑚𝜔 𝐹� (equa𝑒 �(�� but in the samemagnetically 𝑡 ) = that 𝐹�ties value for Forced Vibration can suspend filler ) + 𝑖𝜔𝑐 + 𝑘 𝑋 = 𝐹 �� field (Marke, 2005). It can be achieved expressedfield (Marke, iωt ( ) (2-2) 𝐹(𝑡) = 𝐹(𝑆𝑖𝑛𝜔𝑡 + 𝑖𝐶𝑜𝑠𝜔𝑡) = 𝐹𝑒 𝐹 tion 𝑡 =(2-2) 𝐹𝑒 that F( t ) = Fe therefore the transmitted force zero magnetic field and maximum �(�� ∅) �(�� ∅) atvertical direction only. mass 𝐹� (should )translated ) �=(𝑡𝐹 𝐹 𝑒 but in the same = 𝐹 𝑒 but in the same 𝑡should given as follow: � be be out phase with excitation force which written as 𝐹 2005). It expressed clearly by following formula: �(�� ∅)can clearly bybe Though�for engine vibration case, the mass 𝐹� (𝑡 ) = but infollowing the sameformula: �𝑒 6) �� (�� ∅)) i( ωt -∅ (𝑡) 𝐹= FT (t)=F e𝑒𝑅𝑒�𝐹�but the𝐹same time. FT = cẋ𝜔+ kx. In an asy. time. 𝐹� = 𝑐𝑥̇ + 𝑘𝑥 . 𝐹�� 𝑒 in� = (2-3) � 𝑆𝑖𝑛𝜔𝑡 T� � 𝐾� − 𝐾 �(�� atvertical ∅) direction 1 +only. (2కharmonic ) ss (𝑡 ) =translated 𝐹should but in the same 𝐹� 𝑒that �sumption (2-9) ( ) the𝐹body moves in simple motion, 𝑀𝑅 % = 𝜔� � thetime. hand, we substitute time. 𝑘𝑥 .=that: 𝐹� =𝐹𝑐𝑥̇ +𝑐𝑥̇ 𝑘𝑥+�� . such ofother equation (2-11) 𝐾 �if � = � � we(𝑡) can=get the�displacement as a function and also 𝜔 time. 𝐹 = 𝑐𝑥̇ + 𝑘𝑥 . 𝐹�� 𝑒 𝐹 � = 𝐹� 𝑆𝑖𝑛𝜔𝑡 (2-3) � of time 𝜔 𝑅𝑒�𝐹 � ) + (2క − �𝜔 (2-4) )� (�−𝑚𝜔 �Where Where K’ is + the stiffness gained due to applica𝐾 �𝑘 )new is the stiffness value + 𝑖𝜔𝑐 𝑋= 𝐹 new value = 𝑐𝑥̇ +and 𝑘𝑥acceleration as(1derivation 𝐹�velocity 𝜔 from displacement � � ivation results into transmitted force time. 𝐹 = 𝑐𝑥̇ + 𝑘𝑥 . of equation (2-11) such that: � tion of magnetic flux and K is the original stiffness Figure (A)towithout magnetic fieldwithout (B) function. Put displacement, velocity and acceleration � � the gained3.due application of magnetic (2-6) (−𝑚𝜔 (−𝑚𝜔 )+ Therefore, magnitude of ++ 𝑖𝜔𝑐 = transmitted 𝐹 +those 𝑖𝜔𝑐 𝑘𝜔 𝑋 𝑘= =)𝑋𝐹 Where oscillated frequency (in � any magnetic flux. ( ) −𝑚𝜔 + 𝑖𝜔𝑐 + 𝑘 𝑋 = 𝐹 at equation (2-1) to gain: = 𝑐𝑥̇ + 𝑘𝑥 (2-4) 𝐹�(2-3) ation the different phase flux and with 𝐾 is magnetic the originalfield stiffness force be determined following (2-6)canwhere (2-6) tted rad/s) and 𝜔� = by natural frequency of the � (−𝑚𝜔 (2-6) 𝑖𝜔𝑐 + 𝑘 )𝑋 = Therefore, the+magnitude of 𝐹 transmitted 2.3. without MRE any flux. applied, equation (2-3)Configuration willmagnetic change into: equation, viz.:(2-3) wing systemwill (also change in rad/s). into: lied, force equation (2-6) can be determined by following method are found recently which is ed On the other hand, if we substitute derivation results into � 𝑥̇ � (2-3) �(2-3) � change applied, equation will change into: applied, equation will into: | |𝐹 + 𝑘 𝑥 (2-5) = √𝑐 There are three to employ MRE in vibration iso𝑻 transmitted force equation (2-3) phaseequation ��∅ where the different applied, (2-3) willmethods change into: equation, viz.: ng (applied, ) 𝑖𝜔𝑐 + 𝑘 𝑋 = 𝐹 𝑒 ��∅ � lator or absorber device. The configuration method could employing both of two configuration at 2.2. MRE Configuration (𝑖𝜔𝑐 + 𝑘)𝑋 = 𝐹� 𝑒 equation will change into: diagram of applied force and its transmitted 2.2. (2-3) Material Characteristic � 𝑥̇ � + (2-3) � � applied, equation will change into: |𝐹𝑻 | = √𝑐 𝑘 𝑥 (2-5) be utilizing the change of elastic modulus of MRE that ��∅ There are three methods to employ MRE (2-7)as (𝑖𝜔𝑐(𝑖𝜔𝑐 𝐹vibration 𝑒 ��∅ +SDOF 𝑘)𝑋 = 𝐹�= 7) force along To+ 𝑘)𝑋 aid the isolation performance forced will be tted �𝑒 defined as = compression / squeeze mode, or one that the same time known asthehybrid (𝑖𝜔𝑐 + 𝑘)𝑋 𝐹� 𝑒 ��∅ which diagram of applied force and its transmitted in vibration isolator or absorber device. (2-7) discussed the researchtowill illustrated at Figure 2.1.: before, l be (2-7) To deduce how much force transmitted theusing ground depends on shear modulus change instead, that known ��∅transmitted (𝑖𝜔𝑐SDOF much force (2-7) + 𝑘)𝑋forced = 𝐹� 𝑒vibration force how along will be eddeduce as Vibration shear The lastcan method found be recently which The mode. configuration method from external excitation force, we can find out the ratio Forced be- mode. system be arecould (2-7) illustrated at Figure force 2.1.: to external excitation force or well is employing both of two configuration at the same time be tween transmitted the ground from external excitation utilizing the change of elastic modulus given as follow: Forced Vibration system can Forced Vibration system can be be known as hybrid mode. known as vibration Transmissibility. The transmissibility Forcedwhich Vibration system can be 𝜔 � given as follow: given asfind follow: for Forced Vibration system can be given as follow: ce, wevalue can out the ratio between given Forced Vibration system can be 𝐹� as follow: 1 + (2క 𝜔� ) � �= � 𝜔 𝜔 𝜔 � 𝜔 � 1+ (2క)�𝜔 )� 𝐹 క𝜔 1 + (2 𝐹� as follow: 𝐹�given (1 − �1𝜔+�(2)క� +𝜔(2 nsmitted force to external excitation � � )�క 𝜔� ) (2-8) � � �= ��= � 𝐹 � 𝜔 � � 𝜔 �𝜔� � �𝜔 �𝜔 �𝜔 � 𝐹 𝐹 � �= � � �+క)(2+ (2 క ) � −1��+ (1 −(1 ) క ) 𝜔 𝜔 ) (2 𝐹 Magnetorheological Material (MR 𝜔� 𝜔� as𝜔� 𝜔 � 𝜔� ce or �𝐹well known vibration (1 − �𝜔 � )� + (2క 𝜔 )� � �= � � � � 𝜔 � and ω_n= natu𝐹 ω = oscillated𝜔frequency � Where (in rad/s) � � −a means ) +to (2కalter material) (1 asThe 𝜔� transmissibility 𝜔� ) the stiffness nsmissibility. 2.2. Material Characteristic

but in the

same

time. 𝐹� = 𝑐𝑥̇ + 𝑘𝑥 . In an

assumption that the body moves in simple harmonic motion, we can get the displacement as a function of time and also

velocity

and

acceleration

as

derivation from displacement function.

Put those displacement, velocity and acceleration at equation (2-1) to gain: (2-6)

(−𝑚𝜔� + 𝑖𝜔𝑐 + 𝑘)𝑋 = 𝐹

On the other hand, if we substitute

derivation results into transmitted force equation (2-3) where the different phase applied, equation (2-3) will change into: (2-7)

(𝑖𝜔𝑐 + 𝑘)𝑋 = 𝐹� 𝑒 ��∅

To deduce how much force transmitted

to the ground from external excitation force, we can find out the ratio between

transmitted force to external excitation force or well known as vibration Transmissibility.

The

transmissibility

value for Forced Vibration system can be given as follow: 𝐹� � �= � 𝐹

1 + (2క

𝜔 � ) 𝜔�

𝜔 � 𝜔 (1 − �𝜔 � )� + (2క 𝜔 )� � �

Where 𝜔 = oscillated frequency (in rad/s) and 𝜔� = natural frequency of the

system (also in rad/s).

To aid the isolation performance as discussed before, the research will using Magnetorheological

Material

(MR

material) as a means to alter the stiffness

of the system. MR material structure generally

consists

of

non-magnetic

polymer material (i.e. rubber or solidlike matrix in case of elastomer) as base that suspend filler magnetically

Figure 3. (A) without magnetic field (B) with magnetic field

The changing extend of mechanical characteristic

(i.e.

shear

modulus,

stiffness, etc.) for MRE defined as

magnetorheological effect (MR effect). MR effect can be calculated by finding

the percentage increment of mechanical properties (can be taken as changing value

of

stiffness)

between

zero

magnetic field and maximum achieved

field (Marke, 2005). It can be expressed clearly by following formula: 𝑀𝑅(%) =

𝐾� − 𝐾 𝐾

Where 𝐾 � is the new stiffness value gained due to application of magnetic

flux and 𝐾 is the original stiffness without any magnetic flux. 2.2. MRE Configuration

ral frequency of the system (also in rad/s).

the system. MRsystem material ue forof Forced Vibration canstructure 2.2. Material Characteristic given generally as follow: consists of non-magnetic

To aid the isolation performance as discussed before,

polymer (i.e. rubber Material or solidthe research material will using Magnetorheological (MR Figure Figure 4 : MRE : Squeeze (left) and Shear: 4. Configuration MRE Configuration 𝜔 � Mode (right) material) as a 1 means toకalter the + (2 ) stiffness of the system. 𝐹� like 𝜔 matrix in case of as base Squeeze �elastomer) Naturally, MRE willand get stiffer with application of magnetic MR material structure generally consists of non-magnetic (left) Shear Mode (right) � =polymer � material𝜔(i.e.�rubber or solid-like in case of field parallel to the force application. Hence in a purpose 𝜔 matrix 𝐹 � magnetically � that suspend filler �that)suspend (1 −as�base + (2 క ) to avoid maximum transmissibility (transmissibility value = elastomer) filler magnetically 𝜔� 𝜔�

ere 𝜔 = oscillated frequency (in

/s) and 𝜔� = natural frequency of the Figure without magnetic field (B) Figure 3 3. : (A)(A) without magnetic field (B) with magnetic tem (also in rad/s). field

with magnetic field

The changing extend of mechanical characteristic (i.e. shear

method are found recently is modulus, stiffness, etc.) for MRE defined as which magnetorheMaterial Characteristic ological effect (MR effect). MR effect can be calculated by employing both performance of two configuration at aid the isolation as

1), we can choose either to make the natural frequency get higher (by making the MRE stiffer), or lesser in a way that transmissibility value is less than 1 by make it softer. However, it was found in this research that the application to make the MRE softer which involving permanent magnet and control magnetic flux in the opposite direction with permanent magnet is really difficult to maintain. Hence the design configuration will focused to make the MRE stiffer. Jurnal Teknik BKI Edisi 02- Desember 2014

same time which known as hybrid Jurnal Teknik BKI 69 cussedthe before, the research will using Edisi 03-Agustus 2016 mode. Figure 5. MRE in Hybrid Mode

Figure 4. MRE PROPULSION Jurnal Teknik BKI

Configuration

:

Squeeze (left) and Shear Mode (right)

PROPULSION

control was used as main algorithm to giving command into the system which will get MRE stiffer in result. This type of control system will active immediately at the control signal and de-activate soon after the signal vanish.

Figure 5 : MRE in Hybrid Mode Configuration 2.4. Control Figure 5. Theory MRE in Hybrid Mode In order to create isolation system that can adapt in any Configuration

situations, we need to create active or semi-active control rather than passive ones. Passive isolation method only isolate system from vibration response (either force or displacement) using fixed mechanical characteristics itemwithout any external power. With this type of isolation, the working frequenct bandwidth that the system able to attenuate is very limited. Therefore, active/semi-active control was more feasible to implement. As have been mentioned in above paragraph, Skyhook 6 Excitation Force

+ + Transmitted Force2

+ -

The force excitation input onto the system have various frequency, such as the magnitude of excitation force and the working frequency variation. The excitation force should be simplified as simple harmonic motion which is the real part of equation (2-2) in sine wave form force where the maximum amplitude of the force will be remain the same along the whole simulation duration. However, the system needs to be observed in different kind of working frequency, specifically where the working frequency is equal to the current natural frequency of the system which has the most severe impact on structure. In order to do that objective, the excitation force will be simulated at each short period. Hence the excitation force will be in the form of Sine Wave. To activate the control signal, the detection of near natural frequency parameter will be used as the most accurate way to tell when the system needs to work. In real practice, it is a common to use frequency counter chip as shown in Figure 6, to gain the frequency magnitude of certain working system. However, this system also includes the algorithm to measure working frequency of the system.

-K-

Add1

1/Mass1

2 Integrator2

x

Integrator3

Fdamp

5

Variable Damping

4

Variable Stiffness

x Fstiff

x

|u|2 Math Function4

+ + Transmitted Force3

|u|2 Math Function5

Figure 6 : System Model in Simulink Jurnal Teknik BKI Edisi 02 - Desember 2014

70


u Sqrt

1


Figure 8. Control Actuator

Figure 8. Control Actuator

Figure 7 : Control Actuator

Figure 3.20. Control Actuator

Using the working frequency parameter, the control actu- Therefore it can be draw form Figure 8 that stiffness is a ator can be set to start trigger the control signal when the function of liner equation F= kx. working frequency have reach 75% value of original natural frequency of the system. Likewise, the control actuator On the Figure other 9.hand, damping factor Staticthe Loading hysteresis loop can be obtained will be deactivated after detected working frequency will with energy method using this formula : energy method using this formula : only remain 25% from the original natural frequency. To be Figure 9.𝑒𝑛𝑒𝑟𝑔𝑦 Static Loading 𝑎𝑟𝑒𝑎 hysteresis loop able to observe the behavior of isolator system, the me(2-10) � 𝛿 = 𝐴𝑟𝑐𝑠𝑖𝑛𝑒 � 𝑥 chanical properties of the material also modelled, basedenergy method using this formula : 𝜋 ∙ � ∙ 𝐹 2 2 on static and dynamic loading test on INSTRON E1000 𝑒𝑛𝑒𝑟𝑔𝑦 𝑎𝑟𝑒𝑎 � enclosed in � hysteresis 𝛿 = is 𝐴𝑟𝑐𝑠𝑖𝑛𝑒 machine. Where the energy area the area 𝑥 𝐹 𝜋 ∙ 2� ∙ 2 loop (integral of force regards to the displacement), x_0 Hence the stiffness and damping factor value were origi- and F is the maximum displacement and maximum load nally come to the produced MRE mechanical characteris- on the hysteresis loop. tic. The stiffness and damping value can be derived from following equation. Figure 8. Control Actuator

Figure 10. Dynamic Load Diagram 9. Static Loading hysteresis loop FigureFigure 8 : Static Loading hysteresis loop

energy method using this formula :

𝑒𝑛𝑒𝑟𝑔𝑦 𝑎𝑟𝑒𝑎 � 𝑥 𝐹 𝜋 ∙ 2� ∙ 2

𝛿 = 𝐴𝑟𝑐𝑠𝑖𝑛𝑒 �

Figure 9 : Dynamic Load Diagram

Figure 10. D

Load Diagram



Figure 3.21. Mechanical Properties Function

71

Jurnal Teknik BKI

PROPULSION PROPULSION 3.

Mechanical Testing

The MRE Production material consists of Small Iron powder (10nm), Silicon, which have been dried and mixed thoroughly and continued with magnetization process. This procedure have been done in order to create anisotropic MRE material which is more efficient in control actuator power.

4.

MRE Isolator Magnetic Circuit

The magnetic circuit of the vibration isolator were configured at Figure 11. Magnetic flux density and the flow have been tested before experiment.

Numerical investigation of such magnetic configuration have been done using Software MagNet 7.5. which can be shown in Figure 12.

5.

TESTING RESULT

Testing for static and dynamic load have been carried out while the coil around isolator have been flowed by electrical current in variation of 0.5 – 2.5 A with 0.5 Ampere increment. The test result can be seen in Figure 13 & 14. The result from mechanical test will become an alogarithm input in order to simulate isolator system behavior. After the mechanical properties were put into the system, the performa can be reviewed according to previous control algorithm in figure 15. The transmitted force into the structure can also be minimized as shown in Figure 16.

6.

Conclusion

As the purpose of this research, the aim and objectives is to make design of smart vibration isolator using MRE in hybrid mode, with consideration of compact design and capable to carry on engine weight load within 10% limit of strain. The design shows smart hybrid isolator with 49% MR effect which capable to carry the intended load in 3% limit strain, the system have been simulated using SIMFigure 11. Testing of MRE Hybrid Isolator at Instron E 1000 ULINK and the performance was proven quite well SDOF Figure 10 : Testing of MRE Hybrid Isolator at Instron E 1000 forced vibration isolation. Compare to the shear / squeeze Figure 11. Testing of MRE Hybrid Isolator at Instron E 1000

Moving Part Reluctance

Shear MRE reluctance

Comp MRE reluctance

Figure 12. Magnetic Circuit Configuration

Fixed Part Reluctance


72


Figure 12. Figure 11Magnetic : MagneticCircuit Circuit Configuration Configuration


Figure 13. Magnetic flux density simulation isolator isolator

isolator

Figure 13. Magnetic flux density simulation

have Figure : Magneticflux flux density density simulation Figure 13.12Magnetic simulation have Stiffness vs Current Input

have

been. been.

been.

Figure 13 : Current vs Stiffness


73

Jurnal Teknik BKI

PROPULSION

Figure 14. Current vs Stiffness

PROPULSION Damping Ratio vs Frequency Ratio

Damping Ratio vs Frequency Ratio

Figure 14 : Damping factor for Current 0 – 2 Ampere

Figure 15. Damping factor for Current 0 – 2 Ampere

Figure 15. Damping factor for Current 0 – 2 Ampere

Figure 15 Figure : Comparison of response displacement at : Without control (up) && With 16. Comparison of response displacement at : Without control (up) WithControl (down)


74


Control (down)

Technical Journal of Classification and Independent Assurance Figure 16. Comparison of response displacement at : Without control (up) & With Control (down)

FigureFigure 16 : Comparison of transmitted control(up) (up)&& With Control (down) 16. Comparison of transmittedforce forceatat: :Without Without control With Control (down) only mode, the hybridmode was showing both advantage peri-mentsand modeling of iron-particle-filled force into the structure can also elastomers.Journal be After the mechanical properties were put magnetorheolo-gical of the Mefrom each mode. Compare to the shear / squeeze only chanics and Physics of Solids1(60): 120–138. minimized as shown in Figure 17. into the system, the performa can be mode, the hybridmode was showing both advantage from Deng HX, Gong XL and Wang LH (2006) Development of each mode. reviewed according to previous control an adaptive tuned vibration absorber with magalgorithm in figure 16. The transmitted 6. CONCLUSION netorheolo-gical elastomer. Smart Materials and 7. Reference Structures 5(15): Doyle, John et al (1990) Feedback Control Theory. MacmilBarton, Janice (2014) Transmissibility – Marine Engineering lan Publishing. Module. University of Southampton. United King- Elliot,S.J. (2015) Feedforward Control – Advance Control dom. Design.University of Southampton. United KingBazinenkov, Alexey et al (2015). Active and Semi Active dom. Vibration Isolation Systems Based on Magnetorhe- Ginder JM, Nichols ME, Elie LD, et al. (2001) Controllaological Materials. Proceedings of the 2nd Internable-stiffness components based on magnetorheotional. logical elastomers. In:Smart structures and materials Behrooz M, Sutrisno J, Wang XJ, et al. (2011) A new isolator 2000: smart structures and integrated systems (ed for vibration control. NM Werely), Newport Beach, CA, 6–9 March, pp. BRITISH INTERNATIONAL STANDARD (2005) Rubber, vul418–425. Bellingham: SPIE-International Society for canized or thermoplastics Determination of dyOptical Engineering namic properties. Part 1 – General Guidance BS ISO In:Active and passive smart structures and integrated sys4664-1. United Kingdom. tems 2011(ed MN Ghasemi-Nejhad), San Diego, CA, Cambridge University (2013) Materials Data Book. Engi7–10 March, p. 79770Z. Bellingham: SPIE-Internaneering Department. United Kingdom. tional Society for Optical Engineering. Carlson JD and Jolly MR (2000) MR fluid, foam and elas- INSTRON HELP PAGE (no date). WaveMatrix Software – to-mer devices.Mechatronics4(10): 555–569. V1.8 Onwards.M22-16102 – EN Revision D. Choi, Won Jun (2009) Dynamic Analysis of Magnetorheo- INSTRON HELP PAGE (no date). Blue Hill Software – V2 Onlogical Elastomer Configured Sandwich Structures. wards. M21-16102 – EN Revision D. Doctoral Dissertation. Southampton University. Kallio, Marke (2005), The elastic and damping properties United Kingdom. of magnetorheological elastomers.VIT Publication. Collette C, Kroll G, Saive G, et al. (2010) On magnetorheFinland. olo-gic elastomers for vibration isolation, damping, Lamancusa, J. S., (2002) Vibration Isolation. Penn State Uniand stress reduction in mass-varying structures. versity. United States of America. Journal of Intelligent Material Systems and Struc- Leblanc, J.L. (2002. Rubber-filler interactions and rheologitures15(21): 1463–1469. cal properties in filled compounds. Prog. Polym. Sci. Conference on Dynamics and Vibroacoustics of Machines 27, pp. 627.687. (DVM2014)September 15 – 17 volumes 106 pp. 170 Li, Yancheng et al (2013) On the magnetic field and tem– 174. Russia. perature monitoring of a solenoid coil for a novel Danas K, Kankanala SV and Triantafyllidis N (2012) Exmagnetorheological elastomer base isolator. UniJurnal Teknik BKI Edisi 02- Desember 2014


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PROPULSION PROPULSION versity of Technology Sydney. Australia. Piersol, Allan G., Paez, Thomas L. (2010) Harris’ Shock and Vibration Handbook. Mc Graw Hill. New York. USA. Popp, Kristin et al (2009) MRE properties under shear and squeeze modes and applications. University of Wollongong. Australia. Ruddy, C. et al (2012) A review of magnetorheological elastomers: properties and applications. AMS Research Sapouna, Kyriaki (2009) Smart Vibration Isolator for Marine Engine Vibration Control. MSc Dissertation. Southampton University. Unsal, Memet (2006) semi-active vibration control ofa parallel platform mechanism using magnetorheo-

Hardika Ratditya Ardyanto adalah staf peneliti di Divisi Riset dan Pengembangan PT. Biro Klasifikasi Indonesia (Persero). Penulis menyelesaikan pendidikan Sarjana Teknik pada tahun 2008 di Jurusan Teknik Perkapalan, FTK, Institut Teknologi Sepuluh Nopember (ITS) Surabaya dan menyelesaikan pendidikan Master of Marine Engineering pada tahun 2015 di Jurnal Teknik BKI Southampton University-Inggris spesialisasi Marine RoEdisi 02 - Desember 2014 botics.

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logical damping.Doctoral Dissertation. University of Florida. United States. Vasudevan, M.P. et al (2015) Enhanced microactuation withmagnetic field curing of magnetorheological elastomers based on iron–natural rubber nanocomposites.Indian Academy of Sciences. India. Yang, J. (2014) A novel magnetorheological elastomer isolator with negative changing stiffness for vibration reduction. University of Wollongong. Australia. Y. Liu, T.P. Waters, M.J. Brennan. (2005). A comparison of semi-active damping control strategies for vibration isolation of harmonic disturbances. Journal of Sound and Vibration 280. pp 21–39

RANCANG BANGUN SISTEM PENGINJEKSIAN GAS PADA MODIFIKASI DUAL FUEL DIESEL ENGINE Puji Dhian Wijaya, I Made Ariana, Semin Sanuri

Abstract Cadangan minyak bumi semakin lama semakin berkurang, sehingga banyak penelitian yang dilakukan untuk menyelesaikan permasalahan ini, seperti memodifikasi diesel menjadi dual fuel. Sistem kerja dari dual fuel adalah memasukkan CNG kedalam ruang bakar bersamaan dengan udara pada saat langkah hisap di intake manifold dan akan ikut terbakar dengan solar sebagai pematiknya. Untuk mengkonversi solar ke CNG, perlu dihitung nilai kalor dari masing – masing bahan bakar tersebut. Metode yang dapat digunakan adalah berdasarkan GPA Standard dan komposisi atom penyusun CNG. Setelah didapatkan nilai kalor, perlu dianalisa nilai dari Low Explosive Limit dan High Explosion Limit dari CNG untuk mengetahui apakah bahan bakar gas dan oksigen cukup untuk melakukan pembakaran. Spesifikasi dari komponen – komponen yang diperlukan dalam konverter kit ini disesuaikan dengan standar spesifikasi untuk dioperasikan dengan CNG. Pengujian alat ini dapat dilakukan tanpa mengurangi bahan bakar solar dan kemudian ditambahkan dengan CNG. Berdasarkan hasil pengujian, CNG mampu mensubtitusi kebutuhan solar sampai 75%. . Keywords : CNG, Dual Fuel, Nilai Kalor, Solar.

1.

Pendahuluan

D

alam industri perkapalan, mesin penggerak yang paling banyak digunakan adalah mesin diesel. Namun dengan adanya kenaikan harga minyak mentah dan pasokannya yang semakin berkurang, pemakaian mesin diesel akan semakin tidak efisien dikemudian hari. Jika diamati dengan lebih seksama, kerugian yang dihasilkan karena pemakaian bahan bakar minyak mencakup segi ekonomis dan juga lingkungan. Oleh karena itu pengembangan bahan bakar alternatif semakin gencar dilakukan oleh berbagai pihak sebagai bentuk solusi dari dampak penggunaan bahan bakar minyak. Bahan bakar alternatif lain adalah menggunakan sistem baru pada bahan bakar kendaraan, yaitu sistem bahan bakar ganda, atau lebih dikenal dengan Dual Fuel System. Sistem bahan bakar ganda ini lebih ramah lingkungan jika dibandingkan dengan sistem bahan bakar tunggal (solar). Dual Fuel System ini juga dinilai jauh lebih ekonomis. Dual fuel system atau sistem berbahan bakar ganda memiliki hasil pembakaran yang jauh lebih bersih, (Ehsan, 2009). Kombinasi bahan bakar yang dipakai dalam sistem ini adalah solar dan gas alam. Potensi peman-

Jurnal Teknik BKI

PROPULSION

faatan gas alam sebagai pengganti bahan bakar minyak seperti solar, sangat besar jika diterapkan di Indonesia. Hal ini terkait dengan sumber gas di Indonesia masih relatif banyak dan belum dimanfaatkan secara maksimal. Jenis gas alam yang dipakai adalah Compressed Natural Gas (CNG) dimana gas alam terkompresi ini mengandung lebih dari 90% metana. Dari segi harga, CNG jauh lebih murah dibandingkan dengan bahan bakar gas lain karena tidak melalui proses pencairan dan lainnya (Clarke, 2012). Oleh karena itu, penerapan sistem berbahan bakar ganda diharapkan mampu menghemat pengeluaran konsumsi bahan bakar serta mengurangi emisi gas buang yang dihasilkan oleh mesin dengan sistem berbahan bakar tunggal.

2.

Tinjauan Pustaka

Bahan bakar alternatif yang banyak diaplikasikan dalam modifikasi Dual Fuel Diesel Engine adalah bahan bakar gas, dimana gas (CNG) tersebut dicampurkan dengan udara segar di intake manifold (atau disuntikkan ke dalam silinder) dan dimasukkan ke dalam silinder dan dinyalakan oleh sejumlah kecil bahan bakar diesel ketika piston mendekati akhir langkah kompresi (TMA kompresi). Partikel-partikel bahan bakar halus bercampur dengan

77


Jurnal Teknik BKI


Tabel 1. Spesifikasi CNG (Sumber : PT. Lapindo Brantas Indonesia, 2014) Jurnal Teknik BKI

PROPULSION PROPULSION udara untuk membentuk campuran yang mudah terbakar yang yang kemudian menyatu karena suhu tinggi. Ledakan yang menghasilkan pembakaran dari kompresi tersebut kemudian ikut membakar gas secara langsung karena sudah bercampur dengan udara dan solar, (Ehsan, 2012). Pada modifikasi motor diesel normal menjadi dual fuel, udara murni yang dihisap akan dicampurkan dengan gas, sehingga hanya sedikit volume solar yang dibutuhkan supaya terjadi ledakan. Motor diesel bahan bakar campuran gas kebanyakan menggunakan intake valve untuk memasukan gas bersamaan dengan udara murni. Pengoperasian dengan mode dual fuel ini dapat mengurangi emisi-emisi oksida nitrogen (NOx) mendekati 85%. Selain itu, pada saat beroperasi dengan gas alam dan bahan bakar berkadar belerang rendah, motor-motor diesal berbahan bakar ganda menghasilkan level-level kandungan SOx dan arang-para nyaris nol, (ABS, 2012). Jika terjadi gangguan pasokan gas, motor diesel dual fuel akan mengganti pengoperasiannya dari gas menjadi murni. Pengoperasian denganminyak mode dual fuelpada ini dapat pengoperasian bahan bakar (solar) beban mengurangi emisi-emisi oksida nitrogen (NOx) berapapun secara otomatis. Selama pengoperasian bahan mendekati 85%. Selain itu, pada saat beroperasi bakar minyak, motor dual fuel menggunakan proses diesel dengan gas alam dan bahan bakar berkadar belerang konvensional. Karena pada dasarnya sistem dual fuel ini rendah, motor-motor diesal berbahan bakar ganda adalah motor diesel biasa, maka apabilaSOx terjadi menghasilkan level-level kandungan dangangguan, arangsistem otomatis paraakan nyarissecara nol. (ABS, 2012) pindah ke diesel konvensional walau motor sedang beroperasi. Tabel Spesifikasi CNG Tabel 1 : 1.Spesifikasi CNG (Sumber : PT. Lapindo Brantas Indonesia, 2014)

(Sumber : PT. Lapindo Brantas Indonesia, 2014) No. 1 2 3 4 5 6 7 8 9 10

2.1.

Komponen (i) N2 CO2 CH4 C2H6 C3H8 i-C4H10 n-C4H10 i-C5H12 n-C5H12 C6+

Komposisi (Mol %) 1.720 1.353 94.034 1.650 0.818 0.194 0.060 0.075 0.040 0.056

Tabel 2. Spesifikasi Diesel Yanmar TF85 MH

Karakteristik CNG

Engine (four stroke cycle)

TF85 MH

Displacement

493 cc 18 2200 RPM 7.5 kW 171 gr/HP.h 0.07 mL

CNG (Compressed Gas) atau biasa disebut dengan NumberNatural of cylinders 1 gas alam terkompresi alternatif yang Combustionadalah systembahan bakar Direct Injection Bore dari suatu campuran 85 mm bersih. CNG terbentuk gas-gas yang Stroke 87 mm dihasilkan dari proses fermentasi bahan organik oleh Jurnal Teknik BKI Ratio EdisiCompression 02 - Desember 2014

78

Max. Engine speed at full load Continous Output Jurnal TeknikPower BKI Edisi 03-Agustus 2016 Specific Fuel Consumption Volume per Injection

No. Komponen (i) Komposisi (Mol %) 1 N2 1.720 1.353 2 CO2 94.034 3 CH4 4 C2H6 1.650 bakteri dalam keadaan tanpa oksigen. CNG adalah gas 5 C3H8 0.818 bumi yang dipampatkan pada tekanan 6 i-C4H10 0.194tinggi sehingga volumenya7 menjadi 1/250 dari volume gas bumi n-Csekitar 0.060 4H10 pada keadaan standar. Tekanan pemampatan CNG bisa 8 i-C5H12 0.075 mencapai 9250 barn-C pada 0.040Spesifikasi CNG 5H12suhu atmosferik. secara rinci disampaikan pada Tabel 2. 10 C6+ 0.056 2. Spesifikasi Diesel Yanmar TF85 MH Tabel 2Tabel : Spesifikasi Diesel Yanmar TF85 MH

Engine (four stroke cycle) Number of cylinders Combustion system Bore Stroke Displacement Compression Ratio Max. Engine speed at full load Continous Power Output Specific Fuel Consumption Volume per Injection

2.1.1. NilaiKalor Kalor (Heating Value) 1. Nilai (Heating Value)

TF85 MH 1 Direct Injection 85 mm 87 mm 493 cc 18 2200 RPM 7.5 kW 171 gr/HP.h 0.07 mL

2

 C (Z Z  S S  R S

 Id G  R G

b. Nilai kom

Perh atom bera oksid pada untu pem men

 ∆  ∆ co  M  M  M  M  ∆  Lo LH  Lo H

kalor merupakan energi kalor yang Nilai Nilai kalor merupakan jumlahjumlah energi kalor yang dilepaskan dilepaskan bahan bakar pada waktu terjadinya Formula yang digunakan untuk menentukan nilai bahan bakar pada waktu terjadinya oksidasi unsur – unsur – unsur yang ada pada bahan dari oksidasi heating unsur value gas dapatkimia diambil dari formula kimia yang ada pada bahan bakar tersebut. Harga nilai bakaryang tersebut. Hargaoleh nilaisuatu kalorasosiasi solar diambil standar ditetapkan atau dari kalor solar diambil dari penelitian yang sudah dilakukan penelitian yang seperti sudahGPAdilakukan sebelumnya. badan internasional, (Gas Processors sebelumnya. Sedangkan untuk nilai kalor CNG dalam Sedangkan untuk nilai kalor CNG dalam penelitian ini Association) 0 penelitian ini ditentukan dengan membandingkan data ditentukan dengan membandingkan data dari  Compressibility factor ideal Gas at 60 F and dari 14.696 penelitian sebelumnya dengan hasil dari metode penelitian sebelumnya dengan hasil dari metode psia (Z) 2. Explosiv berdasarkanGPA GPAStandard Standard 2172 2172 ––8686: : Zperhitungan = 1 – {Hi.Vbi}².14,696 perhitungan berdasarkan 0 Calculation Grossheating heating Value,  Compressibility factor gas at 60Value, F and Relative 14.7 psiaDensity Calculation of of Gross Relative Density Explosiv and Compressibility Factor of Natural Gas Mixture (Zb) and Compressibility Factor of Natural Gas Mixture from Range from Analysis dan GPA Standard 2261 Zb = 1Compositional – {Hi.Vbi}².Pb Compositional Analysis dan GPA Standard 2261 – 89 : konsent – 89: Analysis for Ideal Natural Gas and Similar Gaseous  Spesific Gravity Gas Analysis for Natural Gas and Similar Gaseous Mixture by normal, Mixture by Gas Chromatograph serta dengan SG Ideal = E{Hi.Gi} Gas Chromatograph perhitungan nilai kalor bila dib perhitungan nilaiserta kalordengan berdasarkan komposisi atom  Real Spesific Gravity terjadi k berdasarkan komposisi atomCNG dari(C,komponen dari penyusun H, O, N) penyusun SG = {Hi.Gi}.{Pb/14.73}.{0.99949/Zb} Realkomponen CNG (C, H, O, N)

Setiap g a. Nilai kalor berdasarkan  Ideal Gross Heating Value GPA Standard 2172 – 86 LEL (Lo GPA Standard 2261 – 89 GHVdan = E{Hid.Hi} Ideal a. Nilai kalor berdasarkan GPA Standard 2172 – 86 dan  GPA Real Gross Heating Standard 2261Value – 89. GHVReal = {Hid.Hi}.{Pb/14.696}/Zb

Formula yang digunakan untuk menentukan nilai dari

b. Nilai kalor berdasarkan komposisi atom dari heating value gas dapat diambil dari formula standar komponen penyusun CNG (C, H, O, N)

yang ditetapkan oleh suatu asosiasi atau badan internasional, (Gas Processors Association) Perhitungan nilaiseperti kalor GPA berdasarkan komposisi atom penyusun CNG sama halnya dengan mencari berapa nilai untuk panas reaksi akibat terjadinya • Compressibility factor ideal Gas at 600F and 14.696 oksidasi pada setiap unsur atau senyawa yang ada psia (Z) pada CNG. sudah didapatkan nilai panas Z = 1 Ketika – {Hi.Vbi}².14,696 untuk masing – masing senyawa/unsur, panas pembakaran dapat dihitung dengan menjumlahkan nilai – nilai tersebut. (Morris, 2012)

 ∆H°comb = a∆H°fCO₂+ y∆H°fH₂O - y∆H°fO₂  ∆H°comb comp. = vol% comp. x ∆H0reax comp.


• Compressibility factor gas at 600F and 14.7 psia (Zb) Zb = 1 – {Hi.Vbi}².Pb • Spesific Gravity Gas Ideal SGIdeal = E{Hi.Gi} • Real Spesific Gravity SGReal = {Hi.Gi}.{Pb/14.73}.{0.99949/Zb} • Ideal Gross Heating Value GHVIdeal = E{Hid.Hi} • Real Gross Heating Value GHVReal = {Hid.Hi}.{Pb/14.696}/Zb b. Nilai kalor berdasarkan komposisi atom dari komponen penyusun CNG (C, H, O, N). Perhitungan nilai kalor berdasarkan komposisi atom penyusun CNG sama halnya dengan mencari berapa nilai untuk panas reaksi akibat terjadinya oksidasi pada setiap unsur atau senyawa yang ada pada CNG. Ketika sudah didapatkan nilai panas untuk masing – masing senyawa/unsur, panas pembakaran dapat dihitung dengan menjumlahkan nilai – nilai tersebut. (Morris, 2012) • • • • • • • •

∆H°comb = a∆H°fCO₂+ y∆H°fH₂O - y∆H°fO₂ ∆H°comb comp. = vol% comp. x ∆H0reax comp. Mol. mass of comp. = mol mass x vol% Mass% of comp. = vol%/mol mass of comp. Mol. mass of NG = ∑(mol mass x vol%) Mass% of NG = vol% / mol mass of NG ∆H°comb of NG = ∑ (∆H°comb of comp.) Low Heating Value LHV = -(∆H°comb of NG) • Low Heating Value HHV = LHV – ∑mol. H x ∆H°reax of H2O

oksigen untuk memulai reaksi. Formula yang digunakan untuk menentukan nilai dari LEL (Low Explosive Limit) dan HEL (High Explosive Limit) secara teoritis adalah : • • • • •

3.

Cst = 21/(0.21 + n) LEL of component = 0.55 x (Cst of comp.) HEL of component = 3.5 x (Cst of comp.) ∑LEL = 100 / ∑(Ci/LELi) ∑HEL = 100 / ∑(Ci/HELi)

Proses Penelitian

Pada tahap awal pengerjaan penelitian ini dimulai dengan membuat desain perancangan komponen – komponen yang diperlukan untuk membuat sistem ini. Sistem penginjeksian gas ini terdiri dari tabung gas CNG, regulator high pressure, katup pneumatic (solenoid), flow control, flowmeter, gas tubing dan fitting. Komponen – komponen tersebut berfungsi sebagai satu sistem yang saling terintegrasi untuk menginjeksikan bahan bakar gas dari tabung CNG yang bertekanan tinggi sampai ke intake manifold dengan tekanan yang jauh lebih rendah. Selain itu perlu dipersiapkan motor diesel yang akan dikonversi menjadi dual fuel.

2.1.2. Explosive Limit Explosive limit juga dikenal dengan istilah Flammable Range yaitu batas antara maksimum dan minimum konsentrasi campuran uap bahan bakar dan udara normal, yang dapat menyala / meledak setiap saat bila diberi sumber panas. Di luar batas ini tidak akan terjadi kebakaran, (Coward, 1952). Setiap gas memiliki dua macam explosive limit, yaitu LEL (Low Explosive Limit) dan HEL (High Explosive Limit). Jika konsentrasi gas tersebut berada dibawah LEL, maka ledakan tidak akan terjadi karena kurangnya bahan bakar. Dan jika konsentrasi berada di atas HEL, maka tidak tersedia cukup

Gambar 1 : Desain Rancangan Sistem Penginjeksian Bahan Bakar CNG Sebelum mendapatkan jumlah gas yang mampu menggantikan energy panas yang dihasilkan oleh solar, perlu diketahui nilai dari heating value (nilai kalor) masing – masing bahan bakar. Kemudian dari nilai kalor tersebut akan diperoleh besarnya CNG yang mampu menggantikan kebutuhan solar di motor diesel. Setelah dilakukan analisa dan perhitungan serta mendapatkan desain yang direncanakan, maka dilanjutkan dengan pembuatan Jurnal Teknik BKI Edisi 02- Desember 2014 Jurnal Teknik BKI Edisi 03-Agustus 2016

79

CO2 Gambar. 1. Desain Rancangan Sistem Penginjeksian Bahan Bakar CNG

Jurnal Teknik BKI

2

PROPULSION

Combustio n Products

393.51 241.81 285.83

H2O(g)

H2O(liq) Sebelum mendapatkan jumlah gas yang mampu menggantikan energy panas yang dihasilkan oleh solar, perlu diketahui nilai dari heating value (nilai kalor) masing – masing bahan bakar. Kemudian dari nilai kalor Tabel 5. Molar dari ∆H°reax pada5temperature 250C (KJ/g-mol) prototipe converter kit ini. Tabel : tersebut akan diperoleh besarnya CNG yang mampu (Sumber : FREED database, 2012) 0 Molar dari ∆H°reax pada temperature 25 C (KJ/g-mol) menggantikan kebutuhan solar di motor diesel. Setelah Pada tahap selanjutnya, akan dilakukan uji kerja eksperimen dilakukan analisa dan perhitungan serta mendapatkan Reaction to form H2O(g) dengan desain pengujian beberapa variasi pembebanan. yang direncanakan, maka dilanjutkan dengan 2O2 + CH4 → CO2 + 2H2O(g) -802.33 Pengujianpembuatan ini akan membandingkan besar bahan prototipe converter kit konsumsi ini. 3½O2 + C2H6 → 2CO2 + 3H2O(g) -1427.8 bakar solar dan gas serta selisih nilai kalor yang dihasilkan 5O2 + C3H8 → 3CO2 + 4H2O(g) -2043.9 tahap selanjutnya, akan dilakukan uji inikerja sebelum Pada dan sesudah diterapkannya aplikasi dual fuel 6½O2 + C4H10 → 4CO2 + 5H2O(g) -2657.0 dengan pengujian beberapa 3 variasi di motor eksperimen diesel. Reaction to form condense water vapor 3 pembebanan. Pengujian ini akan membandingkan dibawah H2O(g) → H2O(liq) -44.02 dibawah karena 4. ANALISA DANbahan PEMBAHASAN besarDATA konsumsi bakar solar dan gas serta selisih 4. Analisa Data dan Pembahasan i berada karena 4. ANALISA Sumber : FREED database, 2012) si nilai DATA kalor DAN yang PEMBAHASAN dihasilkan sebelum dan sesudah Tabel 6. ∆H°comb of components (KJ/g-mol) si berada diterapkannya aplikasi dual fuel ini di motor diesel. gen untuk 4.1 Nilai CNG dan Solar Kalor Tabel 6 : ∆H°comb of components gen untuk untuk4.1. 4.1 Nilai NilaiCNG CNG dan dan Solar Solar Kalor Kalor an an imit)untuk dan Nilai kalor dari CNG menurut publikasi ilmiah John W Vol % Mol mass mass % ∆H°comb Vol % Mol mass mass % ∆H°comb imit) Nilaikalor kalor dari CNG menurut publikasi ilmiah WW dari CNG menurut publikasi ilmiahJohn John ah : danNilai Bartok dan data dari lembaga internasional seperti N2 1.72 28.01 0.027906 0 N2 1.72 28.01 0.027906 0 lah : Bartok dan data of dari lembagaand National Standards Technology seperti (NIST) Bartok danInstitute data dari lembaga internasional internasional seperti CO2 1.353 44.01 0.034491 0 CO2 1.353 44.01 0.034491 0 3 Standards and Technology (NIST) National Institute of adalah 1030 BTU/ft perhitungan CH4 94.034 16.04 0.873662 -754.46 National Institute of3. Sedangkan Standards hasil and dari Technology (NIST) adalah 1030 BTU/ft . Sedangkan hasil dari perhitungan CH 94.034 16.04 0.873662 -754.46 4 mp.) nilai 1030 kalor BTU/ft3. (heating Sedangkan value) darihasil CNGdari berdasarkan C2H6 1.65 30.07 0.028739 -23.5583 adalah perhitungan mp.) nilai kalor (heating dari Standard CNG berdasarkan C2H6 1.65 30.07 0.028739 -23.5583 p.) formula – formula yangvalue) ada di GPA 2172 – 86 C 0.818 44.097 0.020894 -16.7194 3H8 nilai kalor (heating value) dari CNG berdasarkan formula p.) formula formula 2261 yang –ada GPA2)Standard C3H8 0.818 44.097 0.020894 -16.7194 dan GPA–Standard 89 di (tabel adalah 2172 – 86 C H + 0.425 58.124 0.014309 -11.2921 4 10 – formula ada 2261 di GPA Standard dan GPAyang Standard – 89 (tabel 2) 2172 adalah– 86 dan GPA C4H10 + 0.425 58.124 0.014309 -11.2921

PROPULSION

Tabel 3.Perhitungan Nilai Kalor CNGpada Berdasarkan Standard 2261 – 89 dapat dilihat TabelGPA 3. Standard

Tabel 3.Perhitungan CNG Berdasarkan GPA Standard 2172 – 86Nilai danKalor GPA Standard 2261 – 89 2172 – 863dan GPA Standard 2261 – 89 Tabel : Nilai Kalor CNG

No Formula Value Units dimulai No Formula Value 1 Z 0.99779 -Units i dimulai mponen – 1 Z 0.99779 2 Zb 0.9978 -mponen istem ini.– 2 Zb 0.9978 3 SGIdeal 0.59739 -sistemgas ini. bung 3 SG 0.59739 Ideal 4 SGReal 0.596606 -bung gas neumatic SGReal 0.596606 [BTU/ft 3 1015.2351 ] 54 GHV Ideal pneumatic 3 bing dan 5 GHV 1015.2351 [BTU/ft Ideal 6 GHVReal 1017,7504 [BTU/ft3]] bing dan berfungsi 6 GHVReal 1017,7504 [BTU/ft3] berfungsi asi untuk Berikut ini adalah detail perhitungan untuk besarnya asi untuk CNG yangDetail perhitungan nilai kaloruntuk (heating value) Berikut ini adalah besarnya detail perhitungan besarnya CNG yang nilai kalor (heating value) berdasarkan komposisi atom d dengan berdasarkan komposisi atom penyusunnya disajikan pada nilai kalor (heating berdasarkan penyusunnya adalahvalue) sebagai berikut : komposisi atom dtudengan perluTabel 4. penyusunnya adalah sebagai berikut : itu perlu dikonversi Tabel 4.Molar ∆H°f pada temperature 250 C (KJ/g-mol) dikonversi Tabel 4 4.Molar : Molar ∆H°f Pada Temperatur 250C Tabel ∆H°f temperature 250 C (KJ/g-mol) (Sumber :pada FREED database, 2012)

han Bakar han Bakar

mampu mampu oleh solar, oleh solar, lai kalor) lai kalor) nilai kalor nilai kalor g mampu gl. mampu Setelah el. Setelah 80 dapatkan dapatkan n dengan n dengan

(Sumber : FREED database, 2012)

N oN o

Details Details

1 1

Natural Natural Gas Gas Constituen Constituen s s

2 2

Combustio Combustio n n Products Products

∆H°f ∆H°f

CH4 4 CCH 2H6 C 2H6 C3H8 C3H8

-74.81 -74.81 -84.68 -84.68 103.85 C4H10 -103.85 C4H10 126.15 CO2 -126.15 CO2 393.51 H2O(g) -393.51 H2O(g) 241.81 H2O(liq) -241.81 H2O(liq) 285.83 285.83

Sumber : FREED database, 2012)

Jurnal Teknikdari BKI∆H°reax pada temperature 250C (KJ/g-mol) Tabel 5. Molar Edisi - Desember Tabel 5. 02 Molar dari ∆H°reax pada temperature (Sumber :2014 FREED database, 2012)250C (KJ/g-mol) (Sumber : FREED database, 2012)

Jurnal Teknik BKI Reaction to form H2O(g) Edisi 03-Agustus Reaction2016 to form H O(g)

2O2 + CH4 → CO2 + 2H2O(g) 2 →→ CO2CO 2O2 + +CH 2 + 2H2O(g) 3½O C42H 2 6 2 + 3H2O(g)

-802.33 -802.33 -1427.8

Tabel 7. Perhitungan Nilai Kalor CNG Berdasarkan Komposisi Atom

Explosive Explosive 14.7288 [ 14.7288 [ karena te karena ter kemungki kemungki kekuranga kekuranga

4.3 Kebut 4.3 Kebut

Diketahui

Tabel 7.7Perhitungan Nilai Kalor CNG Berdasarkan Komposisi Atom Diketahui Tabel : Perhitungan Nilai Kalor CNG Berdasarkan Penyusunnya bakar sola Penyusunnya bakar sola Komposisi Atom Penyusunnya satuan vo

satuan vo satuan m satuan m penginjek penginjek 0.05831 g 0.05831 g pembakar pembakar (2200 RPM (2200 RPM mengalika Dari beberapa referensi yang ada dan juga hasil mengalika konsumsi Dari beberapa referensi yang ada dan juga hasil konsumsi perhitungan menggunakan duadan metode Dari beberapadengan referensi yang ada jugayang hasilMJ. perhitungan dengan menggunakan dua metode yang MJ. berbeda, maka diperoleh 4 variasi nilai kalor perhitungan dengandiperoleh menggunakan dua metode yang berbeda, maka 4 variasi nilai kalor berdasarkan metode – metode yang berbeda, yaitu Berdasark berbeda, maka diperoleh 4 variasi nilai kalor berdasarkan berdasarkan 3 metode – metode3 yang berbeda, 3yaitu Berdasark 1030 BTU/ft3 ; 1017,7504 BTU/ft3 ; 913.784 BTU/ft3 dan 3 referensi, metode – metode yang berbeda, yaitu 1030 ; 1030 BTU/ft ; 1017,7504 BTU/ft ; 913.784 BTU/ftBTU/ft dan referensi, 1111.821 BTU/ft333. sola 1111.821BTU/ft BTU/ft .; 913.784 BTU/ft3 dan 1111.821 BTU/ft3bakar 1017,7504 .bakar sola low heatin heatin Selain data nilai kalor Compressed Natural Gas (CNG), low adalah da Selaindata datanilai nilai kalor kalor Compressed Natural Gas (CNG), Selain Compressed Natural Gas (CNG), adalah da diperlukan pula data spesifikasi Solar (Diesel Fuel) energi yan diperlukan pula data spesifikasi Solar (Diesel Fuel) energi yan diperlukan pula data besarnya spesifikasi Solaryang (Diesel Fuel) untukpenginjek untuk menentukan energi terjadi dalam untuk menentukan besarnya energi yang terjadi dalam penginjek proses pembakaran mesin. yang Berdasarkan tabel proses 3.5. dengan m menentukan besarnya energi terjadi dalam proses pembakaran mesin. Berdasarkan tabel 3.5. dengan m (Lampiran mesin. Keputusan DirjentabelMigas 3675 pembakaran Berdasarkan 3.5. (Lampiran (Lampiran Keputusan Dirjen Migas 3675 K/24/DJM/2006 tanggal 17 Maret 2006) dan data dari Keputusan Dirjen Migas K/24/DJM/2006 tanggal K/24/DJM/2006 tanggal3675 17 Maret 2006) dan data dari 174.4 Sistem Alternative Fuels Data Center (AFDC), nilai kalor dari 4.4 Sistem Maret 2006) dan Alternative Data Center Alternative Fuelsdata Datadari Center (AFDC), Fuels nilai kalor dari Solar adalah 960.79 BTU/ft33. Sebelum (AFDC), nilai kalor dariBTU/ft Solar .adalah 960.79 BTU/ft3. Solar adalah 960.79 Sebelum bahan ba bahan ba 4.2 Explosive Limit CNG terlebih d 4.2 Explosive 4.2. Explosive Limit Limit CNG CNG terlebih d bahan ba bak Hasil dari perhitungan explosive limit dari CNG bahan sampai m Hasil dari perhitungan explosive limit dari CNG sampai berdasarkan formulaexplosive – formula dan Denganm Hasil dari perhitungan limitdari dariH.F.Coward CNG berdasarkan berdasarkan formula – formula dari H.F.Coward dan Dengan G.W. Jones adalahdari sebagai berikut dan : formula – formula H.F.Coward G.W. Jones adalahdiesel (so G.W. Jones adalah sebagai berikut : diesel (so sebagai berikut : CNG, mo Tabel 8. Nilai Low Explosive Limit dan High Ecplosive Limit dari CNG, mo beban yan Tabel 8. Nilai Low Explosivepenyusun Limit danCNG High(vol%) Ecplosive Limit dari komponen beban yan komponen penyusun CNG (vol%) No No 1 1 2 2 3 3 4 4

Formula Value Formula Value 17.264 Mol. mass of NG Mol. mass of NG 17.264 ∆H°comb of NG -806.029 ∆H°comb of NG -806.029 LHV 913.784 LHV 913.784 HHV 1111.821 HHV 1111.821

Methane Methane Ethane Ethane Propane Propane Butanes,dll

CH4 CH4 C2H6 C2H6 C3H8 C3H8 C4H10 +

LEL LEL 5 5 3 3 2.2 2.2 1.9

Units Units kJ/g-mol kJ/g-mol BTU/ft3 BTU/ft33 BTU/ft BTU/ft3

HEL HEL 15 15 15 15 9.5 9.5 8.5

Langkah Langkah yang bera yang bera lebih 200 lebih 200 dahulu te dahulu te Regulator Regulator

Solar adalah 960.79 BTU/ft 3. Solar adalah 960.79 BTU/ft .

Sebelum pengoperasian alat atau menginjeksikan Sebelumbakar pengoperasian menginjeksikan bahan gas, motor alat dieselatau tersebut dijalankan bahan bakar gas, motor diesel tersebut dijalankan 4.2 Explosive Limit CNG terlebih dahulu selama kurun waktu tertentu dengan 4.2 Explosive Limit CNG terlebih dahulu selama kurun waktu tertentu dengan bahan bakar solar. Beban diberikan dan dipertahankan Technical Journal of Classification and Independent Assurance bahan bakar solar. Beban diberikan dan dipertahankan Hasil dari perhitungan explosive limit dari CNG sampai motor mencapai kondisi operasi normal (idle). Hasil dari perhitungan explosive dari CNG sampai motor kondisi operasi bahan normal bakar (idle). berdasarkan formula – formula dari limit H.F.Coward dan Dengan tanpamencapai mengurangi kuantitas berdasarkan formula – formula dari H.F.Coward dan Dengan tanpa mengurangi kuantitas bahan bakar G.W. Jones adalah sebagai berikut : diesel (solar) dan sekaligus membuka katup kontrol G.W. Jones adalah sebagai berikut : diesel motor (solar) bisa dan dioperasikan sekaligus membuka katup kontrol CNG, untuk kecepatan dan Tabel 8Tabel : Nilai Low Explosive Limit Ecplosive bakar gas, motor diesel tersebut dijalankan 8. Nilai Low Explosive Limit dandan HighHigh Ecplosive Limit dariLimitCNG, motor bisa dioperasikan untuk kecepatan dan terlebih beban yang diinginkan. Tabel 8. Nilai Low Explosive Limit danCNG High(vol%) Ecplosive Limit dari komponen penyusun dari komponen penyusun CNG (vol%) dahulu selama kurun waktu tertentu dengan bahan beban yang diinginkan. komponen penyusun CNG (vol%)

bakarberikutnya solar. Beban diberikan dipertahankan Langkah adalah bahandan bakar gas (CNG) sampai Langkah berikutnya adalah bahan bakar gas(kurang (CNG) motor mencapai kondisi operasi normal (idle). Dengan yang berada dalam tabung bertekanan tinggi Methane CH4 yang berada dalam tabung bertekanan tinggi (kurang mengurangi bahan bakar diesel (solar) lebihtanpa 200 bar) dikeluarkankuantitas dengan menurunkan terlebih Methane 4 Ethane CCH 2H 6 lebih 200tekanannya bar) dikeluarkan dengan menurunkanPressure terlebih dahulu dengan menggunakan dan sekaligus membuka katup kontrol CNG, motor bisa Ethane C2H H6 Propane C 3 8 dahulu tekanannya dengan sesuai menggunakan Pressure Regulator sampai tekanannya dengan kebutuhan Propane C CH3H8+ dioperasikan untuk kecepatan dan beban yang diinginkan. Butanes,dll 4 10 Regulator sampai tekanannya sesuai dengan penurunan kebutuhan konsumsi bahan bakar. Setelah dilakukan C Butanes,dll 4H10 + Carbone Dioxide CO2 konsumsiCNG bahan bakar. Setelahkedilakukan penurunan tekanan, akan dilewatkan safety valve dengan CO CarboneNitrogen Dioxide Langkah berikutnya adalahkebahan bakar gas (CNG) yang N22 tekanan, CNG akan dilewatkan safety valve dengan tujuan jika terjadi over pressure, maka gas akan N2 Nitrogen berada dalam tabung bertekanan tinggi (kurang lebih tujuan jika dari terjadi over dan pressure, maka gas akan dikeluarkan sistem sistem secara otomatis Tabel 9. Hasil Perhitungan Nilai Low Explosive Limit dan High dikeluarkan dari sistem sistem secara otomatis Tabel 9Tabel : Hasil Perhitungan Nilai Low Explosive Limit danberhenti 200 bar) dikeluarkan dengan menurunkan terlebih 9. Hasil Perhitungan Nilai Low Explosive beroperasi (off).dan Safety valve juga dapat dahulu Ecplosive Limit CNG Total (vol%)Limit dan High berhenti beroperasi (off). Safety valve juga dapatRegulator Ecplosive Limit TotalTotal (vol%)(vol%) High Explosive LimitCNG CNG tekanannya dengan menggunakan Pressure difungsikan sebagai emergency stop. difungsikan sebagai emergency stop. No Formula Value Units sampai tekanannya sesuai dengan kebutuhan konsumsi No ∑LEL Formula 4.8950 Value [vol%] Units 1 Katup kedua yangSetelah dilewatidilakukan oleh CNG adalah cuttekanan, off bahan bakar. penurunan CNG 1 ∑LEL 4.8950 [vol%] [vol%] Katup Fungsi kedua utama yang dari dilewati oleh CNG adalah cut off 2 ∑HEL 14.728 valve. katup ini adalah sebagai katup akan dilewatkan ke safety valve dengan tujuan jika terjadi 2 ∑HEL 14.728 [vol%] valve. Fungsi utama dari katup ini adalah katup on dan off dari sistem ini. akan Jadi ada 2sebagai katupdari yang over pressure, maka gas dikeluarkan sistem dan on dan off dari sistem ini. Jadi ada 2 katup Dari hasil yang didapatkan dapat disimpulkan bahwa berfungsi sebagai safety system dari konverter kityang ini. sistem secara safety otomatis berhenti beroperasi (off). Safety Darihasil hasilLEL yang didapatkan disimpulkan Dari yang didapatkan dapat disimpulkan bahwaberfungsi system dari oleh konverter kit ini. dengan (Low Explosivedapat Limit) dan HEL bahwa (High Komponensebagai berikutnya yang dilewati CNG adalah dengan LEL (Low Explosive Limit) dan HEL (High valve juga dapat difungsikan sebagai emergency dengan LEL (Low Explosive Limit) dan HEL (High ExplosiveKomponen berikutnya yang dilewati oleh CNG adalahstop. LEL LEL5 5 3 2.23 2.2 1.9 1.9 5.22 5.22 2.87 2.87

HEL HEL 15 15 15 15 9.5 9.5 8.5 8.5 33.25 33.25 60.74 60.74

Limit) dari CNG sebesar 4.8950 [vol%] dan 14.7288 [vol%], maka ledakan (explotion) bisa terjadi karena tersedia cukup oksigen (HEL<15) dan memiliki kemungkinan untuk tidak terjadi karena adanya kekurangan bahan bakar (LEL<5). 4.3.

Kebutuhan Bahan Bakar

Diketahui bahwa nilai kalor (heating value) dari bahan bakar solar adalah 960.79 BTU/ft3 (35.837 MJ/L) dalam satuan volume dan bernilai 44.3886 MJ/kg dalam satuan massa. Konsumsi solar untuk satu kali penginjeksian berdasarkan perhitungan diatas adalah 0.05831 gr (0.07 mL). Maka energi yang dihasilkan oleh pembakaran dari motor diesel pada putaran maksimal (2200 RPM) berdasarkan nilai kalornya sama dengan mengalikan nilai kalor dari solar dengan besarnya konsumsi bahan bakar solar per injeksi adalah 0.002588 MJ. Berdasarkan nilai kalor diatas dan dari beberapa referensi, diketahui bahwa hasil pengkonversian bahan bakar solar dan CNG dengan acuan energy content atau low heating value dari masing – masing bahan bakar adalah dalam 1 m3 CNG atau 0.78 kg CNG memiliki nilai energi yang sama dengan 1.14 L solar. Jadi dalam 1 kali penginjeksian bahan bakar solar sebesar 0.07 mL setara dengan memasukkan 57 mL CNG kedalam ruang bakar. 4.4.

Sistem Penginjeksian Gas

Sebelum pengoperasian alat atau menginjeksikan bahan

Katup kedua yang dilewati oleh CNG adalah cut off valve. Fungsi utama dari katup ini adalah sebagai katup on dan off dari sistem ini. Jadi ada 2 katup yang berfungsi sebagai safety system dari konverter kit ini. Komponen berikutnya yang dilewati oleh CNG adalah flow control. Pada sistem ini, flow control berfungsi sebagai pengatur atau pengendali besar kecilnya aliran fluida (debit). Untuk mengkalibrasi jumlah debit dari CNG, dapat dilihat dengan menggunakan flowmeter yang diletakan setelah flow control ini. Untuk menginjeksikan bahan bakar gas (CNG) ke intake manifold, dibutuhkan waktu (timing) yang tepat. Waktu penginjeksian gas ini diatur oleh katup timing yang letaknya berada didekat intake manifold. Setiap kali sensor membaca tanda yang sudah dibuat di gear, timing valve ini secara otomatis akan membuka. Dan ketika sudah tidak ada inputan dari sensor, katup timing ini akan menutup. Durasi membukanya katup intake adalah selama 0,035 detik. 4.5.

Perbandingan Nilai Kalor Solar dan CNG-Solar

Saat pengujian, variable tetap yang digunakan adalah pembebanan 1 – 5 kW pada 3 variasi RPM (1500 RPM, 1800 RPM, 2200 RPM). Sedangkan untuk bahan bakar yang diuji adalah pada kondisi solar normal, dan dengan penambahan CNG secara konstan sebesar 5,7 mL per injeksi dan 11,4 mL per injeksi. Jurnal Teknik BKI Edisi 02- Desember 2014 Jurnal Teknik BKI Edisi 03-Agustus 2016

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PROPULSION

7 7

PROPULSION 1500 RPM (Penambahan CNG Konstan Sebesar 5,7 mL per Injeksi)

Gambar. 2. Grafik Nilai Kalor Vs Pembebanan Pada 1500 RPM Untuk Penambahan CNG Konstan Sebesar 5,7 mL per Injeksi

Gambar 2 : Grafik Nilai Kalor Vs Pembebanan Pada 1500 RPM (5,7 mL)


1800 RPM (Penambahan CNG Konstan Sebesar 5,7 mL per Injeksi)

8 Gambar. 3.Gambar Grafik Nilai Kalor Vs Pembebanan Pada 1800 Untuk Penambahan CNG Konstan Sebesar mL per Injeksi 3 : Grafik Nilai Kalor VsRPM Pembebanan Pada 1800 RPM (5,75,7mL) Gambar. 3. Grafik Nilai Kalor Vs Pembebanan Pada 1800 RPM Untuk Penambahan CNG Konstan Sebesar 5,7 mL per Injeksi



Gambar. 4. Grafik Nilai Kalor Vs Pembebanan Pada 2200 RPM Untuk Penambahan CNG Konstan Sebesar 5,7 mL per Injeksi Gambar. 4. Grafik Nilai Kalor Vs Pembebanan Pada 2200 RPM Untuk Penambahan CNG Konstan Sebesar 5,7 mL per Injeksi




82


Technical Journal of Classification and Independent Assurance Gambar. 4. Grafik Nilai Kalor Vs Pembebanan Pada 2200 RPM Untuk Penambahan CNG Konstan Sebesar 5,7 mL per Injeksi


9



9 9




Gambar. 6. Grafik Nilai Kalor Vs Pembebanan Pada 1800 RPM Untuk Penambahan CNG Konstan Sebesar 11,4 mL per Injeksi Gambar. 6. Grafik Nilai Kalor Vs Pembebanan Pada 1800 RPM Untuk Penambahan CNG Konstan Sebesar 11,4 mL per Injeksi




Putaran Putaran [RPM] Putaran 1500 [RPM] [RPM] 1500 1500

Gambar. 7. Grafik Nilai Kalor Vs Pembebanan Pada 2200 RPM Untuk Penambahan CNG Konstan Sebesar 11,4 mL per Injeksi Tabel 10. Hasil Pengujian Diesel Dengan Penambahan CNG Konstan Sebesar 5,7 mL per Injeksi Gambar. 7. Grafik Nilai Kalor Vs Pembebanan Pada 2200 RPM Untuk Penambahan CNG Konstan Sebesar 11,4 mL per Injeksi Jurnal Teknik BKI Tabel 10. Hasil Pengujian Diesel Dengan Penambahan CNG Konstan Sebesar 5,7 mL per Injeksi Edisi 02- Desember 2014 Waktu Beban Vol % Vol. Tabel 10.Vol Hasil Pengujian Diesel Dengan%HV Penambahan CNG Konstan Sebesar 5,7 mL per Injeksi Solar I Solar II Solar I I Waktu Beban Vol Vol % Vol. %HV [s] [kW] [mL] [mL] [%] [%] Jurnal Teknik BKI Waktu Beban Vol I Vol II % Vol.I %HV Solar Solar Solar I 60 0 4 2 50.0% 43.8% Solar Solar Solar I [s] [kW] [mL] I [mL]II [%] I [%] Edisi 03-Agustus 2016 60 1 7.5 4 46.7% 3.4% [s] [kW] [mL] [mL] [%] [%] 60 0 4 2 50.0% 43.8% 60 2 9.5 5 47.4% -7.9% 60 0 4 2 50.0% 43.8% 1 7.5 4 46.7% 3.4% 60 3 11 7 36.4% -2.3% 60 1 7.5 4 46.7% 3.4%

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Gambar. 7. Grafik Nilai Kalor Vs Pembebanan Pada 2200 RPM Untuk Penambahan CNG Konstan Se

Gambar. 7. Grafik Nilai Kalor Vs Pembebanan Pada 2200 RPM Untuk Penambahan CNG Konstan Se 10. Hasil Pengujian DieselSebesar Dengan Penambahan CNG Konstan Sebesar 5,7 mL Tabel 10 : Hasil Pengujian Diesel DenganTabel Penambahan CNG Konstan 5,7 mL per Injeksi Tabel 10. Hasil Pengujian Diesel Dengan Penambahan CNG Konstan Sebesar 5,7 mL Putaran Waktu Beban Vol Vol % Vol. %HV Solar I Solar II Solar I I Putaran Waktu Beban Vol Vol % Vol. %HV [RPM] [s] [kW] [mL] I [mL]II [%] I [%] Solar Solar Solar I 1500 60 0 4 2 50.0% 43.8% [RPM] [s] [kW] [mL] [mL] [%] [%] 1 7.5 4 46.7% 3.4% 1500 60 0 4 2 50.0% 43.8% 2 9.5 5 47.4% -7.9% 60 1 7.5 4 46.7% 3.4% 3 11 7 36.4% -2.3% 60 2 9.5 5 47.4% -7.9% 4 13 9 30.8% -1.9% 60 3 11 7 36.4% -2.3% 60 5 17 11 35.3% -13.% 4 13 9 30.8% -1.9% 1800 0 6 3 50.0% 12.5% 60 5 17 11 35.3% -13.% 1 8 6 25.0% 21.9% 1800 60 0 6 3 50.0% 12.5% 60 2 9 8 11.1% 30.6% 1 8 6 25.0% 21.9% 3 14 10 28.6% -1.8% 60 2 9 8 11.1% 30.6% 60 4 16 12 25.0% -1.6% 3 14 10 28.6% -1.8% 5 22 15 31.8% -14% 60 4 16 12 25.0% -1.6% 2200 0 14 6 57.1% -30% 60 5 22 15 31.8% -14% 60 1 14 10 28.6% -1.8% 2200 0 6 57.1% -30% 2 17 12 29.4% -7.3% 60 1 14 10 28.6% -1.8% 3 20 16 20.0% -1.2% 60 2 17 12 29.4% -7.3% 60 4 28 19 32.1% -18% 3 20 16 20.0% -1.2% 5 34 25 26.5% -15% 60 4 28 19 32.1% -18% 60

5 34 25 26.5% -15% Tabel 11. Hasil Pengujian Diesel Dengan Penambahan CNG Konstan Sebesar 11,4 Tabel 11 : Hasil Pengujian Diesel Dengan Penambahan CNG Konstan mL per Injeksi Tabel 11. Hasil Pengujian Diesel Sebesar Dengan 11,4 Penambahan CNG Konstan Sebesar 11,4 Putaran

Waktu

Beban

Putaran [RPM] 1500 [RPM]

Waktu [s] 60 [s] 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60

Beban [kW] 0 [kW] 1 0 2 1 3 2 4 3 5 4 0 5 1 0 2 1 3 2 4 3 5 4 0 5 1 0 2 1 3 2 4 3 5 4

Vol Solar Vol I [mL] Solar I 4 [mL] 7.5 4 9.5 7.5 11 9.5 13 11 17 13 6 17 8 6 9 8 14 9 16 14 22 16 14 22 14 17 14 20 17 28 20 34 28

Vol Solar Vol III [mL] Solar III 2 [mL] 3 2 4 3 6 4 6.5 6 9 6.5 3 9 5 3 7 5 9 7 12 9 15 12 3 15 6 3 9 6 12 9 17 12 21 17

% Vol. Solar % Vol.II [%] II Solar 50.00% [%] 40.00% 50.00% 42.11% 40.00% 54.55% 42.11% 50.00% 54.55% 52.94% 50.00% 50.00% 52.94% 62.50% 50.00% 77.78% 62.50% 64.29% 77.78% 75.00% 64.29% 68.18% 75.00% 21.43% 68.18% 42.86% 21.43% 52.94% 42.86% 60.00% 52.94% 60.71% 60.00% 61.76% 60.71%

%HV II %HV [%] II 137.6% [%] 40.03% 137.6% 21.08% 40.03% 22.75% 21.08% 7.71% 22.75% -2.93% 7.71% 75.04% -2.93% 56.28% 75.04% 61.14% 56.28% 17.88% 61.14% 21.89% 17.88% 2.28% 21.89% -24.9% 2.28% -3.55% -24.9% -2.93% -3.55% -2.49% -2.93% -12.4% -2.49% -16.1% -12.4%

60

5

34

21

61.76%

-16.1%

1500

1800 1800

2200 2200

84

Berdasarkan hasil pengujian, pada penambahan CNG sebesar 5,7 mL per injeksi, cenderun sampai 30% dan mensubsitusi kebutuhanCNG solar sebesar hingga 5,7 50%.mL Untuk penambahan CN Berdasarkan hasilmampu pengujian, pada penambahan per injeksi, cenderun Jurnal Teknik BKI Edisi 02 - Desember sampai 2014 cenderung terjadi peningkatan nilai kalor lebih dari 100% dan mampu mensubsitusi kebutuha 30% dan mampu mensubsitusi kebutuhan solar hingga 50%. Untuk penambahan CN cenderung terjadi peningkatan nilai kalor lebih dari 100% dan mampu mensubsitusi kebutuha Jurnal Teknik BKI 5. KESIMPULAN Edisi 03-Agustus 2016 5. KESIMPULAN Dari serangkaian tahapan yang telah dilakukan pada penelitian ini didapatkan kesimpulan bah

HV I %] 8% 4% 9% 3% 9% 3.% 5% 9% 6% 8% 6% 4% 0% 8% 3% 2% 8% 5%


Berdasarkan hasil pengujian, pada penambahan CNG sebesar 5,7 mL per injeksi, cenderung terjadi penurunan nilai kalor sampai 30% dan mampu mensubsitusi kebutuhan solar hingga 50%. Untuk penambahan CNG sebesar 11,4 mL per injeksi, cenderung terjadi peningkatan nilai kalor lebih dari 100% dan mampu mensubsitusi kebutuhan solar antara 40 – 75%.

5.

Kesimpulan

Dari serangkaian tahapan yang telah dilakukan pada penelitian ini didapatkan kesimpulan bahwa waktu penginjeksian bahan bakar gas (CNG) adalah selama 0,035 detik pada saat langkah hisap, dimana untuk satu kali penginjeksian CNG adalah sebesar 5,7 mL dan 11,4 mL. Pada sistem yang dirancang ini, CNG mampu mensubtitusi kebutuhan solar sampai 75%.

6.

Ucapan Terima Kasih

Selesainya penelitian ini tidak terlepas dari bantuan banyak pihak yang telah memberikan bantuan dari segi pengetahuan serta beberapa masukan. Lebih khusus ucapan terima kasih yang sebesar-besarnya kepada Bapak Heru Utomo dari PT. Lapindo Brantas dan Bapak Eko Maja Priyanto dari PT. BKI, yang sudah membantu dan membimbing selama pengerjaan penelitian ini.

7.

Daftar Pustaka

A.H Younger. (2004), Natural Gas Processing Principles and Technology – Part I. University of Calgary, USA.

Clarke, S. DeBruyn, J. (2012), Vehicle Conversion to Natural Gas or Biogas. OMAFRA Factsheet Order No.12-043, Canada. Ehsan, Md. (2009), Dual Fuel Performance of a Small Diesel Engine for Applications with Less Frequent Load Variations. Internasional Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol 09 No 10, Bangladesh. Ensola AG. (n.d) Table LEL / UEL. [Internet], Schweiz. Available from : <www.ensola.com> [Accesed 24th May 2014]. Gas Producers Association (2000) GPA Standard 2172 – 86 Calculation of Gross heating Value, Relative Density and Compressibility Factor of Natural Gas Mixture from Compositional Analysis Washington, D.C. United State of America. Gas Producers Association (2000) GPA Standard 2261 – 89 : Analysis for Natural Gas and Similar Gaseous Mixture by Gas Chromatograph Washington, D.C. United State of America. GoWithNaturalGas.ca (2014), Comparing Natural Gas to Diesel – Energy Content. [internet], Canada. Available from: <www.gowithnaturalgas.ca/getting-started/ understand ing-energy-equivalency/> [Accessed 24th March 2014]. Heru, Utomo.([email protected]), 5th March 2014. Re : Komposisi Gas. Email to Puji Dhian Wijaya ([email protected]). H.F.Coward, G.W.Jones. (1952) Limits of Flammability of Gases and Vapors. Bureau of Mines, Bulletin 503, pp. 130 – 134. Morris, Art (2012), Calculating the Heat of Combustion for Natural Gas. [Internet], North America. Available from: < http://www.industrialheating.com/ articles/90561-calculating-the-heat-of-combustionfor-natural-gas/> [Accesed 7th March 2014].

7 0,035 detik pada saat langkah hisap, dimana untuk satu kali penginjeksian CNG adalah sebesar 5,7 mL dan 11,4 mL. Pada sistem yang dirancang ini, CNG mampu mensubtitusi kebutuhan solar sampai 75%.

6. UCAPAN TERIMA KASIH Selesainya penelitian ini tidak terlepas dari bantuan banyak pihak yang telah memberikan bantuan dari segi pengetahuan serta beberapa masukan. Lebih khusus ucapan terima kasih yang sebesar-besarnya kepada Bapak Heru Utomo dari PT. Lapindo Brantas dan Bapak Eko Maja Priyanto dari PT. BKI, yang sudah membantu dan membimbing selama pengerjaan penelitian ini.

Puji Dhian Wijaya, adalah salah satu pemenang Program Beasiswa Penulisan Skripsi BKI 2014. Penulis menempuh studi Strata-1 sebagai mahasiswa Jurusan Teknik Sistem Perkapalan, Fakultas Teknologi Kelautan, Institut Teknologi Sepuluh Nopember Surabaya pada tahun 2010-2014, [email protected]

%HV II [%] 37.6% 0.03% 1.08% 2.75% 7.71% 2.93% 5.04% 6.28% 1.14% 7. DAFTAR PUSTAKA 7.88% 1.89% [1] A.H Younger. (2004), Natural Gas Processing Principles and 2.28% Technology – Part I. University of Calgary, USA 24.9% [2] Heru, Utomo.([email protected]), 5th March 2014. Re : Komposisi Gas. Email to Puji Dhian Wijaya 3.55% ([email protected]) 2.93% H.F.Coward, G.W.Jones. (1952) Limits of Flammability of Gases 2.49% [3]

I Made Ariana, Pengajar di Jurusan Teknik Sistem Perkapalan, Fakultas Teknologi Kelautan, Institut Teknologi Sepuluh Nopember Surabaya, [email protected]. Semin Sanuri, Pengajar di Jurusan Teknik Sistem PerJurnal Teknik BKI kapalan, Fakultas Teknologi Kelautan, Institut Teknologi 02- Desember 2014 Sepuluh Nopember Surabaya, Edisi [email protected] Jurnal Teknik BKI Edisi 03-Agustus 2016

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PROPULSION PROPULSION DAFTAR ALAMAT KANTOR PT. BIRO KLASIFIKASI INDONESIA Kantor Pusat Jl. Yos Sudarso Kav. 38-40, Tanjung Priok, Jakarta Utara - 14320 Phone : (62-21)-4301017, 4301703, 4300993 Facs : (62-21)-43936175 e-mail: [email protected]

Jaringan Pelayanan

Klasifikasi dan Statutoria

Komersil

Belawan

Jl. Veteran No. 218 Belawan Medan - 20411 Phone : (62-61) 6941025 Fax : (62-61) 6941276 e-mail : [email protected]

Jl. Veteran No. 218 Belawan Medan - 20411 Phone : (62-61) 6941157, 6940370 Fax : (62-61) 6941276 e-mail : [email protected]

Batam

Graha BKI, Jl. Yos Sudarso Kav. 5 Batam - 29421 Phone : (62-778) 433388, 429023, 429024, 451288 Facs : (62-778) 429020 e-mail : [email protected]

Graha BKI, Jl. Yos Sudarso Kav. 5 Batam - 29421 Phone : (62-778) 428284, 428438 Facs : (62-778) 429021 e-mail : [email protected]

Pekanbaru

Jl. Ari n Achmad No. 40 Pekanbaru - 28282 Phone : (62-761)-8417295, 8417296 Facs : (62-761)-8417294 e-mail : [email protected]

Jl. Ari n Achmad No. 40 Pekanbaru - 28282 Phone : (62-761) 8417291, 8417292, 7662170 Facs : (62-778) 8417293, 7662180 e-mail : [email protected]

Jambi

Jl. Raden Bahrun No. E11 RT. 11 / RW. 04 Kel. Sungai Putri, Kec. Telanaipura, Jambi Phone : (62-741) 671107 Facs : (62-741) 671108 e-mail : [email protected]

Jl. Raden Bahrun No. E11 RT. 11 / RW. 04 Kel. Sungai Putri, Kec. Telanaipura, Jambi Phone : (62-741) 671107 Facs : (62-741) 671108 e-mail : [email protected]

Palembang

Jl. Perintis Kemerdekaan No. 226, 5 Ilir Palembang - 30115 Phone : (62-711) 713172, 713680, Facs : (62-711) 713173 e-mail : [email protected]

Jl. Perintis Kemerdekaan No. 22, 5 Ilir Palembang - 30115 Phone : (62-711) 713171, 713172, 713680, 717151 Facs : (62-711) 713173 e-mail : [email protected]

Banten

Jl. Gerem Raya KM. 5 No. 1A Kelurahan Gerem, Kecamatan Grogol Cilegon, Banten - 42438 Phone : (62-254) 572673, 573861 Facs : (62-254) 572674 e-mail : [email protected]

Jl. Sultan Ageng Tirtayasa Komplek Istana Cilegon Blok D No. 22 Cilegon, Banten Phone : (62-254) 382347 Facs : (62-254) 382357 e-mail : [email protected]

Tanjung Priok

Jl. Yos Sudarso 38-40 Tanjung Priok Jakarta Utara - 14320 Phone : (62-21) 4301017, 4301703, 4300993, 4353291 Fax : (62-21) 4301702 e-mail : [email protected]

Cirebon

Jl. Tuparev KM. 3 Cirebon - 45153 Phone : (62-231) 201816 Jurnal Teknik BKI Facs : (62-231) 205266 Edisi 02 - Desember 2014: [email protected] e-mail

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Jl. Tuparev KM. 3 Cirebon - 45153 Phone : (62-231) 201816 Facs : (62-231) 205266 e-mail : [email protected]


Jaringan Pelayanan Semarang

Klasifikasi dan Statutoria

Komersil

Jl. Pamularsih No. 12 Semarang - 50148 Phone : (62-24) 7610399 Facs : (62-24) 7610422 e-mail : [email protected]

Jl. Pamularsih No. 12 Semarang - 50148 Phone : (62-24) 7610744 Facs : (62-24) 7610422 e-mail : [email protected] Kantor Perwakilan Komersil Cilacap Perum. Yaktapena Blok E No. 1 Donan Cilacap Phone : (62-282) 537777 Facs : (62-282) 537777 e-mail : [email protected]

Cilacap

Surabaya

Jl. Kalianget No. 14 Surabaya - 60165 Phone : (62-31) 3295448, 3295449, 3295450, 3295451, 3295456 Facs : (62-31) 3294520, 3205451 e-mail : [email protected]

Jl. Kalianget No. 14 Surabaya - 60165 Phone : (62-31) 3295448, 3295449, 3295450, 3295451, 3295456 Facs : (62-31) 3294520, 3205451 e-mail : [email protected]

Pontianak

Jl. Gusti Hamzah No. 211 Pontianak - 78116 Phone : (62-561) 739579 Facs : (62-561) 743107 e-mail : [email protected]

Jl. Gusti Hamzah No. 211 Pontianak - 78116 Phone : (62-561) 739579 Facs : (62-561) 743107 e-mail : [email protected]

Banjarmasin

Jl. Skip Lama No. 19 Banjarmasin - 70117 Phone : (62-511) 3358311, 3350983 Fax : (62-511) 3350175 e-mail : [email protected]

Jl. Skip Lama No. 19 Banjarmasin - 70117 Phone : (62-511) 3367361 Fax : (62-511) 3350175 e-mail : [email protected]

Balikpapan

Kantor Perwakilan Klas Balikpapan Jl. Mulawarman No. 122 H Sepinggan, Balikpapan Phone : (62-542) 8521073, 8521072 Facs : (62-542) 8521073 e-mail : [email protected]

Jl. M. T. Haryono No. 8 Ring Road Balikpapan - 76111 Phone : (62-542) 876637, 876641 Facs : (62-542) 876639 e-mail : [email protected]

Samarinda

Jl. Cipto Mangunkusumo Ruko Rapak Indah No. 10 Samarinda Seberang, Samarinda - 75132 Phone : (62-541) 261423 Facs : (62-541) 261425 e-mail : [email protected]

Makassar

Jl. Sungai Cerekang No. 28 Makassar - 90115 Phone : (62-411) 3611993 Facs : (62-411) 36515460 e-mail : [email protected]

Jl. Sungai Cerekang No. 28 Makassar - 90115 Phone : (62-411) 3611993 Facs : (62-411) 36515460 e-mail : [email protected]

Bitung

Jl. Babe Palar No. 53, Madidir Unet Bitung - 95516 Phone : (62-438) 38720, 38721, 38722 Facs : (62-438) 21828 e-mail : [email protected]

Jl. Babe Palar No. 53, Madidir Unet Bitung - 95516 Phone : (62-438) 34273 Facs : (62-438) 21828 e-mail : [email protected]



87

Jurnal Teknik BKI

PROPULSION PROPULSION Klasifikasi dan Statutoria

Jaringan Pelayanan

Komersil

Ambon

Jl. Laksdya Leo Wattimena, Passo Ambon - 97232 Phone : (62-911) 362805, 362806 Facs : (62-911) 361105 e-mail : [email protected]

Jl. Laksdya Leo Wattimena, Passo Ambon - 97232 Phone : (62-911) 362805, 362806 Facs : (62-911) 361105 e-mail : [email protected]

Sorong

Jl. Jend. Sudirman No. 140 Sorong - 98414 Phone : (62-951) 322600 Facs : (62-951) 323870 e-mail : [email protected]

Jl. Jend. Sudirman No. 140 Sorong - 98414 Phone : (62-951) 322600 Facs : (62-951) 323870 e-mail : [email protected]

Singapura

7500A Beach Road #11-301, The Plaza Singapore - 199597 Phone : 65-68830651, 68830634, 68830643 Facs : 65-63393631 e-mail : [email protected], [email protected]

Strategic Business Unit (SBU) Lepas Pantai

Jl. Yos Sudarso 38-40 Tanjung Priok Jakarta Utara - 14320 Phone : (62-21) 4301017, 4301703, 4300993 Fax : (62-21) 43936175 e-mail : [email protected]

Strategic Business Unit (SBU) Marine

Ruko Green Lake Sunter Jl. Danau Sunter Selatan Blok RC-A Sunter Podomoro, Jakarta Utara Phone : (62-21) 4300139 e-mail : [email protected]

Strategic Business Unit (SBU) Energy

Ruko Green Lake Sunter Jl. Danau Sunter Selatan Blok RC-B Sunter Podomoro, Jakarta - 14350 Phone : (62-21) 43912070, 43933925, 4366843 Facs : (62-21) 43937415 e-mail : [email protected]

Strategic Business Unit (SBU) Industry

Ruko Green Lake Sunter Jl. Danau Sunter Selatan Blok RC-A Sunter Podomoro, Jakarta Utara Phone : (62-21) 4300762 e-mail : [email protected]


88



DAFTARRules RULES& & GUIDELINES Daftar GuideslinesBKI BKI Rules, guidelines dan guidance dibawah ini dapat diunduh melalui http://www.bki.co.id/ajax/Login.php dengan terlebih dahulu membuat akun unduh rules dan guidelines. Part/Vol.

Rules/Guidelines/Guidance

Edition

Part 0 - General Guidance A

Petunjuk Masuk Ruang Tertutup

2014

RULES 2016

I II

Rules for Hull

2014

III

Rules for Machinery Installations

2016

IV

Rules for Electrical Installations

2016

V

Rules for Materials

2014

VI

Rules for Welding

2015

VII

Rules for Automation

2014

VIII

Rules for Refrigerating Installation

2014

IX

2014

X

Rules for Ships Carrying Dangerous Chemicals in Bulk

2014

XI

Rules for Approval of Manufacturers and Service Suppliers

2014

XII

Rules for Fishing Vessel

2003

XIII

Regulation (Rules) for The Redundant Propulsion and Steering Systems

2002

XIV

Rules for Non Metalic Material

2014

XV

Rules Common Structural Rules for Bulk Carrier

2014

XVI

Rules Common Structural Rules for Oil Tanker

2014

1

Guidelines for the Use of Gas as Fuel for Ship

2015

2

Guidelines for Ocean Towage

2001

3

Guidelines for Machinery Conditioning Monitoring

2011

4

Guidelines for the Explosion Protection of Electrical Equipment

2001

Guidelines

5

Guidelines for the Carriage of Refrigerated Containers on Board Ships

2004

6

Guidelines for Analysis Techniques Strength

2005

8

Guidelines for Determination of the Energy Efficiency Design Index

2014

11

Guidelines for Condition Assessment Program

2015

A

Guidance for Ventilation System on Board Seagoing Ships

2004

B

Petunjuk Percobaan Berlayar Kapal Motor (Guidance for Sea Trials of Motor Vessels)

2002

C

Guidance / Petunjuk Pemakaian Ultrasonic Thickness Measurement Report

2006

Guidance


89

Jurnal Teknik BKI

PROPULSION PROPULSION D

Guidance for the Inspection of Anchor Chain Cables

2002

E

Guidance for The Construction And Testing Towing Gears

2000

G

Guidance for the Corrosion Protection and Coating Systems

2004

H I

Guidance for Assessment and Repair of Defects on Propellers Guidance / Petunjuk Klasifikasi dan Survey Kapal Notasi A90 dan A80

2000 2015

K

Guidance for Mass Produces Engines

2016

Part 2-Inland Waterway RULES I

Rules for Inland Waterways - Classification and Survey

2015

II

Rules for Inland Waterway - Hull Construction

2015

III

Rules for Inland Waterway - Machinery Installation

2015

IV

Rules for Inland Waterways - Electrical Installations

2015

V

Rules for Inland Waterways - Additional Requirements of Notation

2015

Part 3-Special Ships RULES I

Rules for Oil Recovery Vessel

2005

II

Rules for Floating Dock

2002

III

Rules for High Speed Craft

2002

IV

Rules for High Speed Vessels

1996

V

Rules for Fibreglass Reinforced Plastics Ships

2016

VI

Peraturan Kapal Kayu

1996

VII

Rules for Small Vessel Up to 24 M

2013

VIII

Rules for Classification and Construction of Wing-in-Ground Craft (WIG CRAFT)

2006

Guidance A Guidance for FRP and Wooden Fishing Vessel up to 24 m Part 4-Special Equipment And Systems

2015

Rules I

Rules for Stowage and Lashing of Containers

2012

II

Rules for Dynamics Positioning Systems

2011

III

Regulation (Rules) for the Bridge Design on Seagoing Ships One Man Console

2004

1

Guidelines for Certification Loading Computer Systems

2015

1-Ina

Pedoman untuk Sertifikasi Sistem Komputer Pemuatan

2015

Guidelines

Guidance A

2012

Reference tries

-

2012

Rules I

2016

II

Rules for Structures

2011

IV

Rules for Machinery Installations

2011


90



V

2011

Rules for Electrical Installations

VII

2011

VIII

2000

IX

Rules for Single Point Mooring

2013

X

Rules for Mobile Offshore Drilling Units and Special Purpose Units

1999

XII

Rules for Facilities on Offshore Installation

2013

2

Guidelines for Classification and Construction Floating Offshore Liquefied Gas Terminals

2013

3

Guidelines for Classification and Construction Floating Production Installation

2016

Guidelines

Guidance 2012

A B

Guidance for Fatigue Assessment of Offshore Structures

2015

C

Guidance for Buckling and Ultimate Strength Assessment of Offshore Structures

2015

Regulation for the Audit and Registration of Safety Management Systems (Bilingual)

2012

Part 6-Statutory I II

2004

System (Bilingual)

Guidelines Guidelines for The Preparation Damage Stability Calculations and Damage Control Documentation on Board

2005

Guidelines on Intact Stability Guidelines on Crew Accommodation

2014 2016

A

Guidance for the Audit and Registration of Safety Management Systems (Bilingual)

2012

B

Guidance for the Verification and Registration of Ship Security Management Systems (Bilingual)

2004

C

Guidance for Inclining Test

2015

Petunjuk Pengujian Kemiringan dan Periode Oleng Kapal

2015

Guidance on Intact Stability

2014

1 3 4 Guidance

C-Ina G

1

Part 7-Class Notation Guidelines 1

Guidelines for Certification of Lifting Appliances (LA)

2013

2

Guidelines for Dynamic Loading Approach

2013

3

Guidelines for Spectral-Based Fatigue Analysis

2013

Guidelines for Livestock Carriers

2015

A

Guidance for the Class Notation Helicopter Deck and Facilities (HELIL & HELIL(SRF))

2013

B

Guidance for Crew Habitability on Ship

2014

4 Guidance

2014

C D

Guidance for Hull Inspection and Maintenance Program

2013

E

Guidance for Planned Maintenance Program

2013

F

Floating Installations and Liftboats

2013


91

Jurnal Teknik BKI

PROPULSION PROPULSION G Guidance for Coating Performance Standards H

Guidance for the Class Notation Emergency Response Service (ERS)

I Guidance for Survey Based on Reliability Centered-maintenance Part 8-Kapal Domestik

2013 2013 2012

Guidelines 1

Pedoman Lambung


92


2016


Pedoman Penulisan JURNAL Jurnal Tenik PEDOMAN PENULISAN TEKNIKBKI BKI 1. Naskah tulisan, dalam bahasa Indonesia atau bahasa Inggris. 2. Format penulisan, maksimal 10 halaman dalam 1 kolom ukuran kertas A4 dengan font Times New Roman ukuran 12, spasi 1,5. Batas atas dan bawah 2,5 cm, tepi kiri 3 cm dan tepi kanan 2,5 cm. 3. Judul, menggunakan huruf capital tebal (bold) ukuran font 14 posisi di tengah 4. Nama penulis, nama lengkap dibawah judul disertai nama instansi dan alamat email dengan huruf miring (italic), ukuran font 10 pt. 5. Foto penulis, dilampirkan foto penulis utama dalam soft copy format jpg atau pdf ukuran minimal 3 x 4. 6. Abstrak, diutamakan dalam bahasa Inggris, ditulis dengan huruf miring (italic) dengan font 10. jarak spasi 1, memuat ringkasan lengkap isi tulisan, maksimum 5% tulisan atau 250 kata. 7. Kata kunci, 2-5 kata, diutamakan bahasa inggris sesuai abstrak. 8. Kerangka tulisan, berisi isi dengan bobot prosentase: • Pendahuluan 5% • Tinjauan Pustaka 15% • Metodologi 20% • Diskusi Hasil & Pembahasan 55% • Kesimpulan dan saran 5% • • •

Ucapan terima kasih (bila ada untuk sponsor, pembimbing, asisten, dsb) Daftar pustaka pengalaman kerja)

9. Kutipan referensi, •

Bila seorang

(Joko, 2014)

•

Bila 2 orang

(Joko & Slamet, 2(14)

•

Bila 3 orang

(Joko, et al., 2014)

10. Daftar pustaka, disusun berdasarkan alphabet, dengan ketentuan sbb: a. Buku: Penulis (Tahun). Judul Buku. Penerbit. b. Jurnal: Penulis (Tahun). Judul Tulisan. Nama Jurnal (cetak miring). Volume (Nomor). Halaman. c. Paper dalam prosiding: Penulis (tahun). Judul Tulisan. Nama Seminar (cetak miring). Tanggal Seminar. Halaman. d. Tesis/TA: Penulis (Tahun). Judul. Tesis/TA. Universitas. e. Engineering Standard: Penulis (Tahun). Judul Buku. Penerbit. f.

Dokumen Pemerintah: Organisasi (Tahun). Nama Dokumen. Tempat.

g. Manual Laboratorium: Judul Manual (Tahun). Nama Buku Manual. Penerbit. 11. Tabel dan Gambar, bisa diedit dan harus diberi nomor secara berurutan sesuai dengan urutan pemunculannya. Setiap gambar dan tabel perlu judul singkat yang diletakkan di atas untuk tabel dan di bawah untuk gambar. Khusus tinggi (min. 350kB). 12. Naskah tulisan dikirim dalam bentuk soft copy ke alamat email [email protected]. 13. Template Jurnal www.bki.co.id.

Propulsion

dapat

diunduh

di


93

PT. BIRO KLASIFIKASI INDONESIA (Persero)

Jl. Yos Sudarso No. 38-40, Tanjung Priok, Jakarta Utara - 14320 Phone : (62-21) 4301017, 4301703, 4300993 Facsimile : (62-21) 43936175, 43901973 email : [email protected]

ISSN : 977246051300

www.bki.co.id

PROPULSION PROPULSION PROPULSION PROPULSION. Jurnal Teknik. Technical Journal of Classification and Independent Assurance

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