Analisis Pengaruh Variasi Sarat Kapal Terhadap Perilaku Gerak dan Tension Tali Tambat LNG Carrier pada Kondisi Offloading di Terminal LNG

Pratama, Shabrian W. (2021) Analisis Pengaruh Variasi Sarat Kapal Terhadap Perilaku Gerak dan Tension Tali Tambat LNG Carrier pada Kondisi Offloading di Terminal LNG. Undergraduate thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Dalam kondisi offloading di terminal LNG, LNG Carrier akan berada pada kondisi tertambat di dermaga. LNG Carrier perlu berada pada posisi yang stabil sehingga proses offloading yang berlangsung dapat berjalan dengan aman. Untuk menjaga keamanan dalam proses yang berlangsung ini, banyak aspek diperlukan sebagai pertimbangan seperti tali tambat, perilaku gerak kapal, gaya pada fender akibat benturan, ataupun beban lingkungan saat terjadi proses offloading. Pada penelitian ini akan dilakukan analisis pengaruh variasi sarat kapal terhadap perilaku gerak kapal dan tension tali tambat LNG Carrier pada kondisi offloading di terminal LNG dengan fasilitas sistem tambat mooring dolphin dengan lokasi penelitian berada di perairan Sulawesi Tengah. Analisis ini menggunakan 2 model kapal (MT Adria dan MT Erawan) dengan 5 arah beban lingkungan collinear (arah 0o, arah 45o, arah 90o, arah 135o, dan arah 180o). Tension tali tambat yang dihasilkan harus menenuhi kriteria keamanan dari OCIMF (Mooring Equipment Guidelines) mengenai safety factor tension tali tambat. Metode yang digunakan dalam analisis ini adalah time domain dan frequency domain. Selain itu, pada penelitian ini juga akan dilakukan analisis offset pada kapal agar tidak melebihi batas operasi Marine Loading Arm sehingga tidak terjadi Emergency Shutdown System. Dari hasil analisis yang dilakukan menunjukkan pada 2 model kapal yang digunakan, MT Adria dan MT Erawan, variasi sarat akibat perubahan muatan yang terjadi akan menghasilkan perilaku gerak kapal yang berbeda pula. Hasil analisis tension tali tambat dengan metode time domain menunjukkan nilai individual maximum tension yang tertinggi terjadi pada arah beban lingkungan 90o dengan kondisi kapal Full Load Ballast. Hasil yang didapatkan kemudian dilakukan plotting trendline untuk mencari keterhubungan antara variasi sarat kapal dengan nilai tension maksimum tali tambat yang terjadi dan menunjukkan bahwa variasi sarat kapal tidak memberikan pengaruh yang linear terhadap nilai maksimum tension tali tambat yang terjadi. Nilai individual maximum tension pada setiap model telah memenuhi kriteria safety factor OCIMF (Mooring Equipment Guidelines) dengan tidak kurang dari nilai safety factor 2. Hasil analisis tension tali tambat dengan metode freqeuncy domain hanya dilakukan pada arah beban lingkungan 90o saja dan menunjukkan pada model MT Adria, nilai propabilistik tension maksimum tali tambat yang paling mungkin terjadi berada di kondisi kapal Full Load Ballast, sementara pada model MT Erawan terjadi berada di kondisi kapal 10% Pay Load Ballast. Terjadi perbedaan nilai berupa kenaikan maupun penurunan yang dihasilkan antara metode time domain dan freqeuncy domain. Dari 2 metode analisis tension tali tambat yang dilakukan menunjukkan bahwa tali tambat yang mengalami tension tertinggi pada setiap model berada di bagian buritan kapal. Dari hasil analisis offset menunjukkan bahwa perubahan posisi kapal ketika tertambay tidak melebihi batas operasi Marine Loading Arm, dengan tidak melebihi batas maksimum gerakan kapal pada moda gerak translasi surge 4m, moda gerak translasi sway 7m, dan moda gerak translasi heave 3m, sehingga tidak akan menyebabkan Emergency Shutdown System. ================================================== In the offloading condition at the LNG terminal, the LNG Carrier will be tied up at the pier. LNG Carrier needs to be in a stable position so that the offloading process that takes place can be run safely. To maintain safety in this ongoing process, many aspects are needed for consideration such as mooring ropes, ship motion behavior, forces on fenders due to collisions, or environmental loads during the offloading process. In this study, an analysis of the effect of vessel draft variation on vessel motion behavior and LNG carrier mooring rope will be analyzed in offloading conditions at the LNG terminal with mooring dolphin system facilities with the research location in Central Sulawesi. This analysis uses 2 ship models (MT Adria and MT Erawan) with 5 collinear environmental load directions (0o direction, 45o direction, 90o direction, 135o direction, and 180o direction). The resulting mooring tension must meet the safety criteria of the OCIMF (Mooring Equipment Guidelines) regarding the safety factor for mooring rope tension. The method used in this analysis is the time domain and frequency domain. In addition, this research will also conduct an offset analysis on the ship so that it does not exceed the operational limit of the Marine Loading Arm so that there is no Emergency Shutdown System. From the results of the analysis carried out, it shows that on the 2 ship models used, MT Adria and MT Erawan, loaded variations due to changes in cargo will result in different ship motion behavior. The results of the mooring rope tension analysis using the time domain method show that the highest individual maximum tension value occurs in the direction of the 90o environmental load with the condition of the Full Load Ballast ship. The results obtained then performed trendline plotting to find a connection between variations of the ship laden with the value of maximum tension mooring ropes and show that the variation laden ship not giving linear effect on the maximum value of mooring rope tension that occurs. The individual maximum tension value in each model has met the safety factor criteria of the OCIMF (Mooring Equipment Guidelines) with no less than the safety factor value 2. The results of the mooring rope tension analysis using the freqeuncy domain method are only carried out in the direction of environmental loads of 90o. The results show that in the MT Adria model, the propabilistic value of the maximum mooring rope tension is most likely to occur in the condition of a Full Load Ballast ship, while in the MT Erawan model it occurs in a 10% Pay Load Ballast condition. There is a difference in value in the form of an increase or decrease in the resulting between the time domain and freqeuncy domain methods. From the 2 methods of mooring rope tension analysis performed, it shows that the mooring rope that experiences the highest tension in each model is at the stern of the ship. From the results of the offset analysis shows that the change in the position of the ship when it is buried does not exceed the operational limit of the Marine Loading Arm, by not exceeding the maximum limit of ship movement in the 4m surge translation mode, 7m sway translational motion mode, and 3m heave translational mode of motion, so it will not cause Emergency Shutdown System.

Item Type: Thesis (Undergraduate)
Uncontrolled Keywords: LNG Carrier, tali tambat, sarat kapal, perilaku gerak, tension, time domain, frequency domain, Marine Loading Arm. LNG Carrier, mooring line, draft vessel, motion behaviour, tension, time domain, frequency domain, Marine Loading Arm.
Subjects: V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering
V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering > VM161 Ships--Hydrodynamics
Divisions: Faculty of Marine Technology (MARTECH) > Ocean Engineering > 38201-(S1) Undergraduate Thesis
Depositing User: Shabrian W. Pratama
Date Deposited: 25 Feb 2021 13:44
Last Modified: 25 Feb 2021 13:45
URI: https://repository.its.ac.id/id/eprint/82884

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