In view of the mooring stability of liquefied natural gas(LNG) bunkering vessels during alongside bukering of cargo ships at non-dedicated terminals under extreme conditions,the ship-to-ship (STS) mooring system for a 30,000 m3?LNG bunkering vessel and a 14,000 TEU LNG dual-fuel container ship at a container terminal is focused on.A shore-side STS mooring solution is proposed.A coupled shore-side STS mooring model is established by numerical analysis software to simulate vessel displacements,mooring line tensions,and fender forces under combined environmental loads (wind,waves,and current).The omnidirectional ultimate environmental load-bearing capacity (critical wind speed/current speed) is forecasted.Furthermore,the impact of mooring line pre-tension on mooring performance is systematically quantified through extended analyses involving various ship type combinations.The results demonstrate that under standard container terminal environmental conditions,this solution meets regulatory requirements for mooring stability during LNG bunkering operations.When the pre-tension is optimized to approximately 13% of the minimum breaking load of the mooring lines,the peak line tension is minimized,and vessel motion displacements can be reduced to below 35% of those observed in scenarios without pre-tension.