Vessel ran out its anchor chain and approached the platform

The incident

A supply vessel at anchor 0.145nm from an oil platform was radioed to begin supply operations. The vessel ran out its anchor chain and approached the platform and tied stern. Once unloading was complete the vessel cast off and began to retrieve its anchor. An unusual amount of weight was noted on the chain and when the anchor broke the surface a sub-sea power cable was observed to be caught on the anchor. The platform was notified and after efforts to free the cable by maneuvering the vessel failed, a decision was made to lower the anchor to the seabed and cut the anchor chain. Divers observed the cable had been moved 15ft and noted a severe kink in the cable as well as stripping of the outer cable housing. Power was not lost to the platform but repair of the cable was required.

Observation

The Master claimed the vessel had previously anchored in the same location whilst engaged in the same type of operation, however, after investigation it became evident the anchor had been dropped in an unauthorised position. A spar buoy indicating the cables location was apparently ignored by the vessel and its position was not checked prior to letting go the anchor. In addition, it was also found that the Master had failed to observe key aspects of the oil field operations manual.

Members should ensure that their navigational policy clearly states the adequate bridge manning requirement and that Masters and watchkeepers are aware of it. This should also be verified periodically by the shore management whenever the opportunity arises such as during internal audits or the superintendent’s regular visits on board.

The incident reinforces the importance of checking position and ensuring charts and navigational aids are consulted prior to anchoring. Masters must also understand and comply with oil field operational instructions and keep apprised of any notices issued by oil field operators.

Financial Cost

The total claims costs were US$ 1,374,952.