Abstract:In order to limit the FPSO to a specific area, a set of tug arrangement scheme for FPSO limit operation is proposed. Based on the MOSES software, the FPSO, mild steel arm, mooring leg and towing cable constitute a multi rigid body coupling calculation model for limit analysis. According to different loading and environmental conditions, the motion response function RAO is calculated by frequency domain analysis, and the motion response of FPSO is simulated in time domain. The spectrum analysis method is used to count the motion response and the force on the towing cable, and the maximum value is calculated. The calculation results provide a reference for the safety and feasibility of limit operations.