VALARIS DS-16 after the casualty.

VALARIS DS-16 after the casualty. (Source: US Coast Guard)

Breakaway of Moored Mobile Offshore Drilling Unit VALARIS DS-16 and Subsequent Collision with Cargo Vessel Akti

What Happened

​On March 12, 2022, about 0020 local time, the mobile offshore drilling unit VALARIS DS-16 was in layup status at the ST Engineering Halter Marine and Offshore Shipyard in Pascagoula, Mississippi, when it broke away from the dock, drifted across the Bayou Casotte channel, and collided with the bulk cargo vessel Akti moored at the Chevron Refinery dock no.6. There were no injuries reported for the 164 crewmembers and personnel on board the VALARIS DS-16 or the 22 crewmembers on board the Akti, and there was no pollution reported. The total damage resulting from the breakaway was estimated at $5 million.

What We Found

​We determined that the probable cause of the breakaway of the VALARIS DS-16 from the ST Engineering Halter Marine and Offshore Shipyard dock and the subsequent collision with the cargo vessel Akti was the failure of one of the shipyard’s mooring bollards—which had been modified to increase its height to accommodate more lines—used to secure the VALARIS DS-16’s bow mooring lines to a pier, during a cold front with strong winds.   ​

Lessons Learned

​​Bollard Inspections

As a result of continuing increases in vessel size and sail area, bollards that were previously sufficient may not have adequate capacity to moor larger vessels. There are currently no US Coast Guard or Occupational Safety and Health Administration regulatory requirements for facilities to inspect and verify loading capacities of bollards at shoreside facilities. Bollards and associated pierside mooring equipment are vital equipment that must be capable of withstanding the tremendous forces that large vessels exert on them. Due to their exposure to seawater, bollards and associated pierside mooring equipment are also at high risk for corrosion, which can significantly affect service life. The Coast Guard has recommended that facility owners and operators develop routine inspection programs for bollards and other mooring equipment.​  ​