Monitoring of a single point moored ship

The offshore platform VEGA is operating since 1988 in Sicily channel with a Single Point Moored tanker ship,. This work shows the overall features of the system and the collection and analysis of the data concerning the structural response of column-yoke-vessel FSO recorded since 2009. The structural monitoring is performed through a series of 37 optical strain gauges installed on the ship and on the yoke, and two biaxial inclinometers installed on SPM. Therefore the following items are monitored: three frames within the ballast tanks, the main structure of the yoke and tilt angles of yoke and mooring column. The acquired data are processed in order to establish their representativeness in relation to the structural control of the yoke/column and the tanker ship. The moored ship is free to rotate and to assume a favorable alignment to the prevailing current, wind or waves, reducing the actions on the mooring column if the loads are collinear. The results of data processing, the spectral analysis and dynamic identifications are presented. The characteristics of the monitoring system installed in the SPM and in the ship allow the dynamic identifications of system.