According to Rigzone, an inquiry into the cause of the Norwegian anchor handling tug supply (AHTS) Bourbon Dolphin capsizing started Wednesday.
The vessel capsized on April 12 during an anchor handling operation with the Highland Valour. Anchor handling is known to be hazardous to the deck crew, but capsizing is rare.
According to reports, the Bourbon Dolphin had recovered an anchor from the seafloor and was about to drop it to a new location when it overturned. The anchor was still attached to the oil rig.
According to reports, Syversen, the sole survivor on the bridge during the accident, added some insight into the incident. He said the Highland Valour attempted five times to move an anchor. On the fifth try the anchor chain dragged
over the side of the AHTS, and the captain of the Bourbon Dolphin requested that the Highland Valour move to the northwest.
When the Bourbon Dolphin attempted to release the inner pin of the anchor, the chain ran free and caught the outer tow pin, which caused the boat to capsize. The emergency release was triggered, but did not perform as designed.
Fifteen crew members were onboard, seven survived, three bodies were found, and five are still missing, thought to be trapped in the vessel.