The Hydrodynamic Model Testing for Closed Loop DP Assisted Mooring

Far East Livingston Shipbuilding (FELS) is presently completing the construction of the Smedvig Production Unit SPU 380, which will be operated as FPSO for Esso BALDER Field Offshore Norway. In good cooperation with FELS and ND&A Inc. of Houston an extensive model test program was carried out for approval and optimization of the DP assisted mooring system.
The main aspects were:

• Investigate the performance of the mooring in two water depths, i.e. 250 m and 70 m.
• Optimization of DP control for the three azimuthing thrusters.
• Measurement of motions and wave induced loads at e.g the bilge keels, keel and deckhouse front.
• Determination of limit sea state for turning the vessel around against the weather.

The tests were carried out in the Wave and Current Basin of MARIN, using a closed loop DP control system to steer the thrusters. The paper presents the findings with respect to the effect of DP control strategy on mooring loads and present selected results of wave induced loads on bilge keels and deck house.

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For this specific paper see: www.onepetro.org/conference-paper/OTC-8261-MS.