Stationkeeping Characteristics of OTEC-1

The problems of vessel stationkeeping, cold water pipe (CWP) gimbal angles, and the interrelationship between the CWP, vessel, and mooring systems relative to positioning and design limits of the OTEC-1 facility OCEAN ENERGY CONVERTER (OEC) are discussed in detail. Unaided sea keeping of the OEC was highly unpredictable. The thrusters provided useful mooring assistance under benign weather and sea conditions but were isufficient to counter extraordinary events. Collision/entanglement of the CWP with the single point mooring was a real hazard; precision real-time positioning data was required to maintain a safe separation. Normal procedures for reducing high CWP gimbal angles included heading changes using the thrusters and ship´s rudder, and ballasting. Detachment of the OEC from the moor was a viable, low risk option in response to high CWP gimbal angles which could not be alleviated using normal procedures.