The U.S. National Transportation Safety Board has released its Marine Accident Brief into the causes of the June 2013 sinking of the offshore supply vessel Celeste Ann after it struck an oil platform in the Gulf of Mexico.
According to the NTSB, the OSV Celeste Ann was receiving passengers from West Delta oil platform 73 about 20 nautical miles south of Grand Isle, Louisiana, when the vessel allided with the platform about 0836 on June 14, 2013. The allision punctured the hull, and the Celeste Ann subsequently flooded and sank. All passengers and crew evacuated to another vessel and no one was injured.
The report continued:
About 0810, the vessel arrived at West Delta 73 platform A to pick up passengers. The junior master backed the vessel into the landing area and held position for the transfer. The vessel was positioned stern in to the platform with its bow into a northwest wind of about 15 knots in 2- to 4-foot seas. Between 0820 and 0830, eight passengers boarded using the crane and man-lift on the platform. Shortly after taking on the passengers, the bow began to swing to starboard and the wind pushed the vessel sideways towards the platform.
The junior master attempted to maneuver the vessel away from the platform, but he was unable to overcome the wind on the vessel’s beam. The Celeste Ann allided with the platform about 0836. The vessel’s starboard side hit the platform twice before the junior master was able to back the vessel away.
About one month after the sinking, the owners of the Celeste Anne, B&J Martin Inc., decided to raise the vessel and bring it to Morgan City, Louisiana, for repairs. A damage survey determined that the initial impact with the landing platform resulted in a 2-inch-wide hole about 7 feet below the waterline near the pump room, while the second impact resulted in two holes in the engine room?one about 1 inch in diameter located 6 feet below the waterline and another about 12 inches by 1 inch about a foot below the first. Estimated costs to salvage and repair the vessel were estimated to be $1 million.
The NTSB determined that the probable cause of the allision was the inability of the junior master to compensate for and overcome wind forces that pushed the vessel into the platform. The NTSB says that contributing to the hull breach and subsequent sinking were underwater protrusions from the platform and open watertight doors on board the vessel.
NTSB Report (opens in PDF): Allision and Sinking of Offshore Supply Vessel Celeste Ann