Outer Continental Shelf National Center of Expertise (OCSNCOE)


NTSB Marine Accident Reports on the OCS

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Excerpt from abstract: This report discusses the September 8, 2011, accident involving the US liftboat Trinity II. Ten persons were on board. Because of severe weather and boarding seas associated with Hurricane Nate, the elevated liftboat’s stern jacking leg failed and the onboard personnel abandoned the vessel. Four of them died... click here

Keywords: Liftboat; Gulf of Mexico; Bay of Campeche; severe weather; jacking leg; abandonment; weather preparedness; lifesaving equipment

Excerpt from abstract: This report explains the sinking of the mobile offshore drilling unit ROWAN GORILLA I on December 15, 1988, in the North Atlantic Ocean. The safety issues discussed are the vessel's design and stability, vessel towing, weather, lifesaving equipment stowage, survival capsule design, survival training, and manning and licensing requirements... click here.

Keywords: MODU; self-elevating type drilling rig; ocean tow; weather; survival capsule; manning and licensing requirements    

Excerpt from Abstract:  On January 15, 1985, the US semi-submersible mobile offshore drilling unit (MODU) GLOMAR ARCTIC II was conducting well testing operations 130 nautical miles east-southeast of Aberdeen, Scotland, in the North Sea. About 2030, the drilling unit experienced an explosion in the port pontoon pumproom. The chief engineer and third assistant engineer were killed in the blast. Damage to the drilling vessel was estimated to be $2.3 million dollars... click here.

Keywords: MODU; explosion; crude oil burner; burner nozzle; temporary equipment; classified locations; ballast control; well testing; evacuation; non-essential; compressed atomizing air; rig air

Excerpt from abstract: About 1230 on September 14, 1984, the U.S.-flag mobile offshore drilling unit (MODU) ZAPATA LEXINGTON suffered an explosion and fire while moored and conducting drilling operations in 1,465 feet of water in the Gulf of Mexico. The accident occurred while procedures were being employed to evacuate a gas bubble from the subsea blowout preventer stack on the sea floor. Instead, gas trapped in the blowout preventer entered the base of the marine riser, rose to the surface, and escaped into the atmosphere, expelling a large volume of drilling mud out of the riser. The gas infiltrated the areas above and below the drill floor at the base of the derrick and was ignited. The explosion and fire that followed resulted in the deaths of four persons and severe injuries to three persons. Sixty-four persons abandoned the MODU using two survival capsules and three inflatable liferafts. The gas fire burned itself out about 30 minutes after the rig was evacuated. The cost of repairs was estimated at $12 million... click here.

Keywords: MODU; drilling rig; formation gas; kick; drilling fluid; drill pipe; blowout preventer (BOP); casing; tool joint; annular; choke manifold; shale shaker; gumbo box; diverter; kill mud; gas-cut mud; lifeboat winch; drill floor

Excerpt from abstract: About 2355 on October 25, 1983, the 400-foot-long United Stated drillship GLOMAR JAVA SEA capsized and sank during Typhoon LEX in the South China Sea about 65 nautical miles south-southwest of Hainan Island, People's Republic of China.  Of the 81 persons who were aboard, 35 bodies have been located, and the remaining 46 persons are missing and presumed dead.  The GLOMAR JAVA SEA currently is resting on the bottom of the sea in an inverted position in about 315 feet of water; its estimated value was $35 million... click here.

Keywords: Drillship; MODU; capsizing; sinking; South China Sea; manning standards; crew qualifications; stability; structures; inspections; lifeboats; emergency radios; typhoon; contingency plans

Excerpt from Abstract: About 0300 on February 15, 1982, the U.S. mobile offshore drilling unit OCEAN RANGER capsized and sank during a severe storm about 166 nautical miles east of St. John's, Newfoundland, Canada; 84 persons were aboard.  Twenty-two bodies have been recovered, and the remaining 62 persons are missing and presumed dead.  The OCEAN RANGER currently is resting in an inverted position in about 260 feet of water; its value was estimated at $125 million... click here.

Keywords: MODU; capsizing; sinking; Grand Banks of Newfoundland; manning standards; crew qualifications; stability; seakeeping; ballast control; hypothermia; exposure suits

Excerpt from abstract: About 1100 c.s.t. on April 14, 1976, the self-elevating drilling unit OCEAN EXPRESS departed a drilling site in the Gulf of Mexico under tow for a new drilling site about 33 nm away.  The OCEAN EXPRESS arrived at the new drilling site about 2330, but was not set in place because of adverse seas.  Three tugs held the OCEAN EXPRESS in position awaiting better weather, but the seas continued to increase.  On April 15, 1976, one tug's starboard reduction gear failed, and another tug's towline broke.  With only one effective tug remaining, the OCEAN EXPRESS turned broadside to the wind and seas, drifted, grounded, capsized, and sank about 2115.  Thirteen persons drowned in a capsized survival capsule... click here.

Keywords: Self-elevating MODU; survival capsule; weather forecasts; towing; operating manual; Gulf of Mexico; industrial personnel; training; jacking limits; contingency plans; grounding; sea; swell; directional control; extreme wave action