Several unfortunate factors contributed to the recent Sleipner A fire, according to Statoil's inquiry report.
A mechanical interlock for two valves which had been placed in the wrong position was the most important direct cause of the blaze.
The report emphasises that the consequences of operating the diesel oil system in a way for which it had not been designed were not adequately evaluated.
An instrument which should have registered that a diesel oil tank was about to overflow also failed to function as intended.
This tank was located in a generator module installed after the North Sea platform came on stream. It seems that risk assessments ahead of this installation were inadequate.
The tank's air vent had been placed close to a hot exhaust duct, and it was through this outlet that 5-6,000 litres of diesel flowed out and caused the fire.
New measures by Statoil to keep flammable liquids away from hot surfaces are recommended by the inquiry team. It also calls for a revision of guidelines on checking alarms, and urges personnel in charge to ensure that minor modifications to technical facilities are protected by alarm systems.
The report confirms the impression that fire-fighting, evacuation and head-counting of crew functioned well.
"There is little doubt that the crew's professional behaviour made a big contribution to limiting the damage," says inquiry leader Finn Strand.
His team also calls for the replacement of emergency response equipment which failed to work adequately, including radios, special fire-fighter clothing and footwear.
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