On the night between 21 and 22 December 2016, the Danish offshore supply ships MÆRSK SEARCHER and MÆRSK SHIPPER capsized and sank in the Bay of Biscay approximately 65 nm off the French coast while being towed by another offshore supply ship, MÆRSK BATTLER, en route to Aliaga, Turkey.
MÆRSK SEARCHER and MÆRSK SHIPPER were configured in a side-by-side towing setup during the voyage. During the passage of the English Channel, the fenders between the ships on tow failed, and the ships started to interact. This caused damage to the ships’ superstructure, which eventually compromised MÆRSK SEARCHER’s watertight integrity and led to water ingress. MÆRSK SEARCHER capsized and sank, and subsequently MÆRSK SHIPPER was pulled under by MÆRSK SEARCHER. The crew on MÆRSK BATTLER carried out a controlled breakage of the towing wire and came loose of the foundered towage.
The DMAIB considered the total loss of the ships is considered a serious accident of special concern to the potential risk of harm to the marine environment. Therefore, the DMAIB in agreement with the French authorities initiated an investigation of the accident to establish the circumstances leading to the foundering of MÆRSK SEARCHER and MÆRSK SHIPPER.
The report can be downloaded in PDF format here.