• Journal of Navigation and Port Research
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• v.45 no.3
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• pp.87-94
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• 2021

The IMO has adopted emission standards that strictly restrict the use of bunker C oil for vessels. Accordingly, research and bunkering pilot projects for LNG fueled ships are being actively carried out, which is expected to substantially reduce environmental pollution. In this study, we have adopted the turret moored Floating LNG Bunkering Terminal (FLBT) designed to receive the LNG from LNGCs and to transfer LNG to LNG bunkering shuttles in ship to ship moored condition. Numerical simulations have been performed with a 1-year return period of wind, wave, and current. Damping values of numerical model were adjusted from the results of model tests to obtain accurate simulation results. The results confirm safe berthing operation during the 1-year return period of environmental condition. Safety depends on the direction of environment, with increasingly stable operation facilitated by the application of heading-control function of FLBT to avoid beam-sea conditions.

• Journal of Ocean Engineering and Technology
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• v.31 no.4
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• pp.266-273
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• 2017

In recent years, LNG bunkering terminals are needed to supply LNG as fuel to meet the emission requirements of the International Maritime Organization (IMO). A floating LNG bunkering terminal (FLBT) is one of the most cost-effective and environmentally friendly LNG bunkering systems for storing LNG and transferring it directly to an LNG fuel vessel. The FLBT maintains its position using mooring systems such as spread mooring and turret mooring. The loads on the vessel and mooring lines must be carefully determined to maintain their positions within the operable area. In this study, the wind loads acting in several side-by-side arrangements on the FLBT and LNG-BS were estimated using wind tunnel tests in the Force Technology, and the shielding effect due to the presence of ships upstream was evaluated. In addition, the empirical formulations proposed by Fujiwara et al. (2012) were used to estimate the wind force coefficients acting on the FLBT and those results were compared with experimental results.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.47-49
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• 2016

국제해사기구가 선박배출가스규제지역 내 질산화물 규제를 적용하고 2020년부터는 항해 중인 모든 선박에 황산화물 규제를 적용하기로 하는 등 선박해양오염 규제가 강화되어, 친환경 연료로 운항하는 LNG Fuel Ship에 대한 수요가 높아지고 있다. 이로 인해 LNG 연료공급 시장규모의 성장이 전망되며 관련시설로 해상 부유상태의 FLBT(Floating LNG Bunkering Terminal)의 기술개발과 연구가 진행 중에 있다. 본 연구목적은 FLBT 시설의 설치에 적합한 후보지를 선정하는 것이다. 영해 내에 위치하고 설계수심과 수요항만과 접근성이 우수한 후보지의 제시를 위해 LNG Fuel Ship의 입출항 예상항만과 해상시설에 대한 국내외 사례조사 및 사전연구에서 제시된 후보수역에 대한 해상교통조사를 수행하고 심층분석 하였다. 조사 및 분석결과를 바탕으로 수요지 접근성과 항행안전을 고려한 FLBT 최종 후보지를 제시하고자 한다.

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.182-182
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• 2017

• Journal of Ocean Engineering and Technology
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• v.32 no.1
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• pp.51-61
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• 2018

In this study, the operability of an FLBT (floating LNG bunkering terminal) was evaluated experimentally. Model tests were conducted in the KRISO (Korea Research Institute of Ships and Ocean Engineering) ocean engineering basin. An FLBT, an LNG carrier, and two LNG bunkering shuttles were moored side by side with mooring ropes and fenders. Two white-noise wave cases, one irregular wave case, and various regular wave cases were generated. The relative local motions between each LNG loading arm and its corresponding manifold in the initial design configuration were calculated from measured 6-DOF motions at the center of gravity of each of the four vessels. Furthermore, the locations of the LNG loading arms and manifolds were varied to minimize the relative local motions.

• Journal of Navigation and Port Research
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• v.44 no.6
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• pp.439-446
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• 2020

The IMO has adopted emission standards through Annex VI of the International Convention for the Prevention of Pollution from Ships (MARPOL) that strictly prohibit the use of bunker C oil for vessels. In this study, we have adopted the turret-moored Floating LNG-Bunkering Terminal (FLBT) which is designed to receive the LNG from LNGCs and transfer it to LNG-bunkering shuttles in side-by-side moored condition. Numerical analyses were carried out using the high-order boundary-element method for four vessels at various relative distances. Mean wave drift forces were compared in an operational sea state. A model test was performed in the ocean engineering basin at the Korea Research Institute of Ships & Ocean Engineering (KRISO) to verify the safety of the berthing/unberthing operation. In the model test, a jig was designed to simulate tug boats pushing or pulling the bunkering vessels, so that the friction force of the g operation was not affected. Safety depended on the environmental direction, with more stable operation possible if the heading-control function of FLBT is applied to avoid beam-sea conditions.

• Journal of Ocean Engineering and Technology
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• v.34 no.2
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• pp.77-88
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• 2020

In this study, heading characteristics and heading control performances were evaluated to achieve the wave shield effect. The wave shield effect originating from heading control reduces the relative motions of moored vessels in a floating liquefied natural gas bunkering terminal (FLBT). Therefore, loading and off-loading performances are improved through reduced relative motion. For the objective of this study and efficiency of the analysis, a simplified model was used that assuming no relative motion of the moored vessels in the FLBT. The simplified model involved modeling the environmental loads and inertia of several floating bodies, including FLBT, into the environmental loads and inertia of a single vessel. The simplified model was validated through comparisons with model tests. With the simplified model, heading characteristics and heading control simulations were performed using low-frequency planar motion equations. The heading characteristics and heading control performances of FLBT were analyzed through the results of simulations under the expected environmental conditions. The capacity of the tunnel thrust for the heading control performance was confirmed to be adequate for improvement of the loading and off-loading performances using the wave shielding effects under the operation conditions.

• Journal of the Korean Institute of Gas
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• v.21 no.1
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• pp.65-71
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• 2017

LNG is being spotlighted as a clean marine fuel because of recent trend in reinforcement of marine environmental regulation. In this paper, demand prospect of LNG bunkering for Ulsan port is carried out to analgize the possibility of commercialization of floating LNG bunkering terminal. Environmental analysis for LNG bunkering and LNG bunkering trends of competitive ports in the world are considered to draw out the prospection of LNG bunkering demand in Ulsan. As a result, car carrie and oil carrier were expected to have more possibility in switching to LNG fuelled ship. The LNG bunkering demand in Ulsan. As a result, car carrier and oil carrier were expected to have more possibility in switching to LNG fuelled ship. The LNG bunkering demand in Ulsan port was expected to be about from 650,000 ton to 900,000 ton in 2030 and Ulsan port is prospected to be a good port for FLBT business in th future.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.2
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• pp.248-253
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• 2023

Most offshore platforms utilize chain mooring systems for position keeping. However, information regarding related design modification processes is scarce in literature. This study focuses on the floating liquefied natural gas (LNG) bunkering terminal (FLBT) as the target of shore platform and analyzes the corresponding initial mooring design and model tests via numerical simulations. Subsequently, based on the modified design conditions, a new mooring system design is proposed. Adjusting the main direction of the mooring line bundle according to the dominant environmental direction is found to significantly reduce the mooring design load. Even turret-moored offshore platforms are exposed to beam sea conditions, leading to high mooring tension due to motions in beam sea conditions. Collinear environmental conditions cannot be considered as design conditions. Mooring design loads occur under complex conditions of wind, waves, and currents in different environmental directions. Therefore, it is essential appropriately assign the roll damping coefficients during mooring analysis because the roll has a significant effect on mooring tension.