The US National Transportation Safety Board (NTSB) has published a preliminary report as part of its ongoing investigation into the capsizing of the liftboat Seacor Power last month near Port Fourchon, Louisiana, USA.
There were 19 people on board when the Seacor Power overturned during extreme weather conditions in the Gulf of Mexico. Six people were rescued by the US Coast Guard and Good Samaritan vessels, while six people died in the accident and seven remained missing.
Seacor Power had left Port Fourchon at about 13:30 on April 13th, heading for the oil and gas lease area Main Pass Block 138 in the Gulf of Mexico. A weather report emailed to the vessel at 07:02 that day predicted afternoon winds at 9 to 12 knots from the southeast with one-metre seas.
NTSB investigators learned that at about 15:30 when the Seacor Power was transiting the open waters of the Gulf, a squall passed over the liftboat. Visibility was dropping and winds were increasing significantly, so the crew decided to lower the Seacor Power’s legs to the seafloor to hold the vessel in position until the storm passed.
The crewmember at the helm attempted to turn the Seacor Power into the wind as the legs began to descend. Before the turn was completed, the liftboat heeled to starboard and capsized.
NTSB investigators found that several people were able to escape onto the exposed, port side of the Seacor Power deckhouse. High winds and seas that had built to three metres prevented rescuers from reaching those who remained on the liftboat. Some were washed into the water; six were eventually rescued, with one survivor suffering a serious injury.
NTSB investigators have interviewed survivors, other personnel who previously crewed the Seacor Power, representatives for the owner and charterer, vessel inspectors and surveyors, and search and rescue responders. When the Seacor Power is salvaged NTSB investigators intend to return to inspect the vessel and collect further evidence.
Meanwhile, the US Coast Guard said on Wednesday that salvage crews had removed all diesel fuel from the tanks of the Seacor Power. About 20,363 gallons of diesel fuel were removed using the hot tapping method.
Some 4,500 gallons of hydraulic fluid still on board will need to be removed after the vessel is raised, because the tanks are currently inaccessible.
The salvors will now look to remove debris and refloat the vessel. The USCG did not anticipate the vessel being raised before June.
A USCG safety zone covering a one nautical mile radius around the incident site, plus a Federal Aviation Administration temporary flight restriction covering a 5nm radius around the site, and a 2,000ft minimum altitude around the site, will be in force until June 15th.