On the night of July 6, 1988, the Piper Alpha oil production platform, operated by Occidental Petroleum some 120 miles northeast of Aberdeen in the North Sea, was torn apart by a series of explosions and fires that burned through the night. Of the 226 men aboard, 167 were killed — among them two rescuers from the standby vessel Sandhaven — making it the deadliest offshore oil disaster in history.
The disaster began with maintenance. That day, a pressure safety valve was removed from the line serving one of the platform’s two condensate injection pumps, and the open pipe was closed with a temporary blind flange. The work was recorded on a permit, but the permit system broke down between shifts: when the operating pump tripped that evening, the night crew, unaware the other pump was partly dismantled, restarted it. Shortly after 10 p.m., gas condensate escaped from the flange and ignited. The first explosion wrecked the production modules and destroyed the control room, and fires fed by the platform’s own oil took hold.
What turned an explosion into a catastrophe was the gas still flowing into the platform. Piper Alpha was connected by pipeline to the Tartan and Claymore platforms, and their risers were not shut in during the crucial first hour — the neighbouring installations kept pumping, their managers reluctant to stop production without authorisation from onshore. At about 10:50 p.m. the Tartan riser, its steel softened by the heat, ruptured, releasing a huge volume of gas that exploded in a fireball and destroyed what remained of the platform’s structure and escape routes.
Most of the men had mustered, as they had been trained, in the accommodation block, waiting for helicopters or orders to evacuate. The block was not smoke-proof, no evacuation was ordered in time, and most of those who died were overcome there by smoke and carbon monoxide. The survivors were, in the main, those who defied the fire and jumped — some from the helideck and pipe deck, falls of well over a hundred feet — into a burning sea, where standby and rescue vessels picked them up. The Sandhaven’s fast rescue craft was caught in the riser explosion and lost with the men it had recovered. By about 12:45 a.m. the platform had collapsed into the sea.
The public inquiry chaired by Lord Cullen, reporting in November 1990, delivered a sweeping indictment of the operator’s safety management and of the official inspection regime that had failed to detect it. Its 106 recommendations reshaped offshore safety: responsibility for offshore safety regulation was transferred to the Health and Safety Executive, and operators of every installation were required to submit a formal Safety Case — a demonstration that major hazards had been identified and their risks reduced to as low as reasonably practicable. The safety case regime, along with new rules on temporary refuges, evacuation and pipeline isolation, remains the foundation of offshore regulation in British waters and has been adopted in much of the world. A memorial to the 167 stands in Hazlehead Park, Aberdeen.