Experimental Study on a Spread Catenary Mooring for FPSO

This paper summarises the main results of experimental tests conducted at the Danish Hydraulic Institute in the frame of the EU-TMR-LSF project “A New Concept of Catenary Mooring System for FPSO”. The main interest of this research project is the analysis of the behaviour of a proposed mooring system for FPSO well suited for weather conditions characterised by a dominant swell and current and by a moderate almost perpendicular local sea and wind. The basic idea of this mooring design is to join the best characteristics of the turret and spread mooring systems to allow the FPSO to move within a specified offset so that the wave loads on the lines and on the vessel can be minimised. The experiments and the related analysis refer to the dynamic behaviour of the FPSO alone and FPSO+Shuttle tanker during offloading, in extreme and operational weather conditions respectively. In the case with the FPSO+Shuttle tanker the tension on the hawser is analysed too.