Ocean Express

Rig:

Ocean Express Jack-up

Date:

15 April 1976

Location:

Gulf of Mexico

Activity:

Rig move

Summary

The Ocean Express was moved on the morning of 14 April 1976 from Mustang Island to a new location in Mustang Island East, 33 miles away. It was towed by 3 tugs: Gulf Knight, Gulf Explorer and Gulf Viking.

At 2300, the rig was about 1 mile from new location and jacking-down of the mat commenced. The tugs were repositioned to bring the rig on location, with the Gulf Viking holding the bow, Gulf Knight on port stern and Gulf Explorer on starboard stern. Jacking-down ceased at approx 0100 as the sea conditions deteriorated, with seas up to around 10 feet by 0600 on 15 April. Through the day, the seas continued to build with swells washing over the decks by afternoon and some water leaking into the accommodation.

At 1510, one of the Gulf Knight's engines failed, followed by the parting of the Gulf Viking's towline at 1930. Numerous attempts were made to reattach the Gulf Viking's towline but heavy seas breaking over the deck frustrated the crews efforts. The water also shifted some of the drillpipe stored in racks on the deck, which the crew tried to resecure. As a result of the water washing over the deck and the loose pipe, work on the towline and pipe was abandoned as conditions became too hazardous. Around 2000, a Marathon Oil representative requested Coast Guard assistance and a Coast Guard helicopter was despatched to evacuate the crew.

At 2115, the derrick shifted to starboard giving the rig an immediate starboard list of up to 25 degrees. The crew then abandoned the rig using survival capsules #1 and #3, sailing into 25 foot seas with 65 mph winds. The Barge Mover remained behind in an attempt to save the rig. However, when the Coast Guard chopper arrived at 2120, the Barge Mover requested evacuation from the heildeck then ordered the tugs to let go their towlines. The Coast Guard chopper then made two abortive approach attempts, during which time the rig's list increased to an estimated 45 degrees.

The pilot's complete lack of visual reference in the night while attempting to hover over the rig rendered the extraction almost impossible but on the chopper's third approach, the winchman managed to lower the passenger basket just in time to scoop up the Barge Mover. The pilot said later that it appeared at this point that the chopper was rapidly losing altitude. The truth was that the rig was actually capsizing and the bow helideck was swinging up underneath the chopper. Seconds after the Barge Mover was picked up, the rig capsized to starboard.

The real tragedy to this story is the aftermath. Although the rig was successfully evacuated with no casualties, the ordeal for the crew of the Ocean Express was not yet over. The 14 crew in capsule #1 were rescued by the Nicole Martin survey vessel, whose captain maneuvered the capsule into the lee of the vessel, allowing the crew to jump from the capsule to the Nicole Martin. Capsule #3 was not so lucky. After coming alongside the Gulf Viking, the capsule was flipped unexpectedly by the high seas and rapidly half-filled with water, preventing the capsule from self-righting. An air pocket formed inside the capsule, but after around 30 minutes only 7 men had managed to escape from it. The other 13 crew were found drowned the next day still inside the capsule.

Causes

Loss of directional control, resulting from the towline breaking and engine failure, was considered the primary cause of the capsize. One of the Marine Investigation Board's findings was that 'allowing a low freeboard self-elevating drilling unit to drift broadside to boarding seas... is an invitation for loss'. The report also noted that the possibility existed that grounding of the rig may have contributed to the capsize. Both the increased weight from boarding seas and the angle of the starboard list allowing the mat to touch bottom may well have resulted in a 'tripping action' which increased the rig's heel to starboard.

Sources:

U.S. Coast Guard: Marine Casualty Report PDF document

Images
1. U.S. Coast Guard PDF document