Ocean Ranger - Sinking

Sinking

On 26 November 1981, Ocean Ranger commenced drilling well J-34, its third well in the Hibernia Oil Field. Ocean Ranger was still working on this well in February 1982 when the incident occurred. Two other semi-submersible rigs were also drilling nearby: the Sedco 706, 8.5 miles (13.7 km) NNE, and the Zapata Ugland, 19.2 miles (30.9 km) N of Ocean Ranger. On 14 February 1982, the rigs received reports of an approaching storm linked to a major Atlantic cyclone from NORDCO Ltd, the company responsible for issuing offshore weather forecasts. The usual method of preparing for bad weather involved hanging-off the drillpipe at the sub-sea wellhead and disconnecting the riser from the sub-sea blowout preventer. Due to surface difficulties and the speed at which the storm developed, the crew of Ocean Ranger were forced to shear the drillpipe after hanging-off, after which they disconnected the riser in the early evening.

At about 1900 hours local time, the nearby Sedco 706 experienced a large rogue wave which damaged some items on deck and caused the loss of a life raft. Soon after, radio transmissions were heard from Ocean Ranger, describing a broken portlight (a porthole window) and water in the ballast control room, with discussions on how best to repair the damage. Ocean Ranger reported experiencing storm seas of 55 feet (17 m), with the odd wave up to 65 feet (20 m), thus leaving the unprotected portlight at 28 feet (8.5 m) above mean sea level vulnerable to wave damage. Some time after 2100 hours, radio conversations originating on Ocean Ranger were heard on the Sedco 706 and Zapata Ugland, noting that valves on Ocean Ranger's ballast control panel appeared to be opening and closing of their own accord. The radio conversations also discussed the 100-knot (190 km/h) winds and waves up to 65 feet (20 m) high. Through the remainder of the evening, routine radio traffic passed between Ocean Ranger, its neighbouring rigs and their individual support boats. Nothing out of the ordinary was noted.

At 0052 hours local time, on 15 February, a Mayday call was sent out from Ocean Ranger, noting a severe list to the port side of the rig and requesting immediate assistance. This was the first communication from Ocean Ranger identifying a major problem. The standby vessel, the M/V Seaforth Highlander, was requested to come in close as countermeasures against the 10—15 degree list were proving ineffective. The onshore MOCAN supervisor was notified of the situation, and the Canadian Forces and Mobil-operated helicopters were alerted just after 0100 hours local time. The M/V Boltentor and the M/V Nordertor, the standby boats of the Sedco 706 and the Zapata Ugland respectively, were also dispatched to Ocean Ranger to provide assistance. At 0130 hours local time, Ocean Ranger transmitted its last message: "There will be no further radio communications from Ocean Ranger. We are going to lifeboat stations." Shortly thereafter, in the middle of the night and in the midst of severe winter weather, the crew abandoned the rig. The rig remained afloat for another ninety minutes, sinking between 0307 and 0313 hours local time.

All of Ocean Ranger sank beneath the Atlantic: by the next morning all that remained was a few buoys. Her entire complement of 84 workers – 46 Mobil employees and 38 contractors from various service companies – were killed. Whilst the rig was provided with an Emergency Procedures Manual which detailed evacuation procedures, it is unclear how effectively the rig evacuation was carried out. There is evidence that at least one lifeboat was successfully launched with up to 36 crew inside, and witnesses on the M/V Seaforth Highlander reported seeing at least 20 crew members in the water at the same time, indicating that at least 56 crew successfully evacuated the rig. The United States Coast Guard report speculated that 'these men either chose to enter the water directly or were thrown into the water as a result of unsuccessful lifesaving equipment launching'. Rescue attempts by the standby vessels were hampered by the adverse weather conditions and the conclusion that the standby boats were neither equipped nor configured to rescue casualties from a cold sea. As a result of the severe weather, the first helicopter did not arrive on scene until 0230 hours local time, by which time most if not all of Ocean Ranger's crew had succumbed to hypothermia and drowned. Over the next week, 22 bodies were recovered from the North Atlantic. Autopsies indicated that those men had died as a result of drowning while in a hypothermic state.

In related activity the following day, the container ship Mekhanik Tarasov was struck by the same weather conditions as Ocean Ranger, approximately sixty-five miles to the east. The battered Soviet freighter listed dramatically for hours before sinking with a heavy loss of life.