Ocean Ranger was a semi-submersible mobile offshore drilling unit that sank in Canadian waters on 15 February 1982. It was drilling an exploration well on the Grand Banks of Newfoundland, 267 kilometres (166 mi) east of St. John's, Newfoundland, for Mobil Oil of Canada, Ltd. (MOCAN) with 84 crew members on board when it sank. There were no survivors.
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 platforms were also drilling nearby: Sedco 706, 8.5 miles (13.7 km) NNE, and Zapata Ugland, 19.2 miles (30.9 km) N of Ocean Ranger. On 14 February 1982, the platforms 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 drill pipe 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 drill pipe after hanging-off, after which they disconnected the riser in the early evening.
At about 19:00 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 the water line vulnerable to wave damage.
Some time after 21:00, radio conversations originating on Ocean Ranger were heard on 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 neighboring rigs and their individual support boats. Nothing out of the ordinary was noted. More details
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 platforms were also drilling nearby: Sedco 706, 8.5 miles (13.7 km) NNE, and Zapata Ugland, 19.2 miles (30.9 km) N of Ocean Ranger. On 14 February 1982, the platforms 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 drill pipe 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 drill pipe after hanging-off, after which they disconnected the riser in the early evening.At about 19:00 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 the water line vulnerable to wave damage.