A Study on the LNG Loading or Unloading Operability of Floating LNG Bunkering Terminal with Ship-to-ship Moored

Abstract

The floating LNG bunkering terminal (FLBT) is a newly emerging offshore platform that can be regarded as a liquefied natural gas (LNG) station at sea. It has its own station-keeping system, and it is additionally moored to other vessels during LNG loading or unloading processes. The ship-to-ship mooring system is composed of a number of mooring ropes and fenders. The relative motion responses between loading arms and corresponding manifolds are crucial for the LNG transfer process, because they have their specified allowable displacement criteria. To investigate the multibody interactions, model tests were performed previously. Some hydrodynamic coefficients obtained from the model test were utilized in numerical simulations. The eigenvalue analysis on multibodies with the ship-to-ship mooring system was also conducted. The natural modes and periods induced by the mooring ropes and fenders were identified. A series of numerical simulations with various incident wave headings and configurations were conducted with the commercial program AQWA. Finally, we judged the operable incident wave heading range under allowable displacement criteria.