Fatigue Life Re-Assessment of FSO Spread Mooring System

Re-assessment fatigue life on spread moored system of Floating Storage and Offloading (FSO) vessel moored in irregular wave has been carried out based on hybrid time-frequency domain approach. Previous assessment work result obtained the fatigue life very conservative about thousands of year, whilst existing mooring system was designed for the operational life of 10 years. Different method from previous work was used in fatigue damage calculation approach for undertaking a fatigue mooring analysis in present work. Present works aim to show that the simple summation method used for previous assessment that cause the large variation in fatigue life obtained by comparing different methods of combining fatigue damage. Comparison between the result of fatigue life both previous assessment and present work (re-assessment) of fatigue life are made and discussed.