Information about damage to anchor bolsters which could be significant for other mobile units has emerged from the PSA’s investigation of a stability incident affecting the Floatel Superior mobile accommodation unit on 7 November. The PSA has notified the industry of this.
The following alert has been issued to all owners of mobile facilities with a Norwegian acknowledgement of compliance (AoC), The Norwegian Maritime Directorate and classification societies:
“Damage has been discovered to bolsters where anchors are attached on a semi-submersible facility which has sailed under its own power from the Far East to Norway and has subsequently been kept on location by dynamic positioning (DP). The damage is thought to have arisen because the anchors have moved horizontally and vertically as a result of wave motion during transport, operation and at survival draft, and have repeatedly inflicted damage to the contact surfaces and the lower bracing members. In the event that a bracing breaks, the damage can escalate so that more parts of the bolster are torn off. Anchors would then hang free. In rough seas, this could cause great damage to support column and pontoon, with loss of watertight integrity as a possible consequence.
“The PSA would request that the owners of floating facilities with an AoC assess this information for their own units. Should damage be discovered, the PSA wishes to be informed of this.”
Press Release, December 18, 2012