MODU Stability Disaster including all the Facts of the Rig Nicknamed, Ocean Danger

MODU Stability Disaster the Facts of the Rig Nicknamed " Ocean Danger "
Ocean Ranger,
platform off Canada sank along with its entire 84 crew, claiming the title of one of the worst offshore drilling accidents in North American history. The incident forms another example of how lack of compliance with procedures and inadequate safety culture can have tragic consequences.
The incident
From November 1981, the Ocean ranger had been working in the Hibernia Oil Field, on the Grand Banks of Newfoundland, 267 km east of St. John’s, Newfoundland, Canada, along with two other semi-submersible platforms nearby, the Sedco 706 and Zapata Ugland.
On 14 February 1982, weather forecast provider NORDCO informed the platforms of deteriorating weather conditions, as a result from a major Atlantic cyclone. The rig had handled several storms in its 6-year past, so it was expected that it could handle this too.
However, in the early morning hours of 15 February, the crew started transmitting a series of desperate distress calls which indicated that the platform was listing badly.
In the middle of the night and amid severe winter weather, the crew abandoned Ocean Ranger. The platform remained afloat for another 90 minutes before going down shortly after 3am.
At least 56 crewmen were seen by eye witnesses having abandoned the platform on a lifeboat or in the water. Search and rescue efforts by sea or air were not feasible due to adverse weather, while standby vessels could not approach due to huge waves.
Fatalities
The entire 84 people onboard - 46 crew and 38 contractors- perished at the disaster, with no survivors. From the 84 bodies, only 22 were recovered. Hypothermia was the cause of death in all of these cases.
In addition, three salvage divers were killed on the wreck during salvage operations, two by an underwater explosion on 20 June and another one on 26 June, after being hit by a dropped object as he attempted to return to the surface.
Probable causes
In its official investigation report, the US Coast Guard identified failure of the Ocean Ranger’s ballast control room portlights as key cause to a sequence of events ending up to loss of the rig. It is noted that the platform had not sustained any structural damage which affected its ability to encounter heavy weather.
Sequence of events
A large wave impacted Ocean Ranger and shattered windows in the Ballast Control Room, soaking the ballast control console. Control panel was lost.
Operators then observed lights on the mimic board flashing from red to green and back, leading them to believe that the valves in the portside pontoon were opening and closing on their own. About an hour later, crew cut electrical power to the console to force the valves to close. This could help the platform encounter weather conditions.
For unknown reasons, crew on the Ocean Ranger restored power to the console approximately four hours later.
After the crew restored power, short circuits or inadvertent operator commands caused valves in the bow to open, allowing water to flood the forward ballast tanks and causing the rig to list toward the bow, according to NASA.
Poor manuals
All of the investigations also underlined the lack of written casualty control procedures, which made the crew uncertain of which is the safest way to address malfunction of the ballast control room.
Similarly, the Ocean Ranger’s Operations Manual was ‘difficult to read’ and ‘not presented in a format suitable for ready reference’, according to USCG. The format language could not be easily understood by masters and ballast control room operators.
Although Ocean Ranger had an Emergency Procedures manual that included steps for evacuation, it did not discuss lead times necessary for helicopters (2 hours) and standby vessels (40 minutes) to conduct rescue,
…NASA added.
Lack of crew training
According to NASA, there was no formal training on ballast control operator position, while there was no training for procedures specific to Ocean Ranger.
While the level of understanding of the Ocean Ranger’s ballast control room operators and masters of the rig’s ballast system was inadequate to deal with extraordinary situations or emergencies,
…USCG explained.
In the same context, all the official narratives by USCG, NTSB and NASA, indicate the crew did not fully understand what to do in case of an emergency involving the Ranger’s ballast control system.
For instance, NTSB narrates that the Ocean Ranger’s toolpusher hungoff the drill string and disconnected the marine riser in accordance with the emergency procedures manual, but he did not discuss evacuation with the company’s superintendent, as it was demanded.
and Poor safety equipment.......
Sources:
safety4sea.com/
Cinenova Productions for CTV and National Geographic US. Directed by Christopher Rowely. Written and researched by Mick Gzowski.