The Piper Alpha Oil Platform disaster was caused by the ignition of condensate flooding from a blind flange that could not withstand the pressure of condensate in the pipe it closed. The blind flange was replacing a valve that had been removed for repair. At the time of removal of the valve, there was no condensate in this pipe, and the blind flange was not intended to withstand the pressure of the condensate. However, the operators in the control room on the night shift were not properly informed by the day shift that the valve had been taken out for repair. That night, operational irregularities occurred. The operators took the natural action of leading the condensate into the alternative pipe, and the potential for tragedy became a fact.
The explosion occurred and led to a large crude oil fire. The explosion in effect destroyed the platform’s main power supplies and the control room, and a series of serious consequences flowed from this, which led to the destruction of the platform and the tragic loss of 167 lives.
There is little doubt that the immediate cause of the disaster was human error but there is rarely one cause of a major accident, more generally a series of incidents (each normally safe or even trivial in themselves) come together, against an existing background to cause it. In the case of Piper Alpha, obvious examples are:
• The unavailability of a crane to replace the repaired valve before the night shift took over. • The lack of knowledge of the absence of the valve by the men on the night shift; and • The fact that the only valve available malfunctioned that night.
The management system by way of “Permit to Work” was found to be ill monitored and the platform itself, through its original design and subsequent adaptation on several occasions, was open to the possibility of accident should circumstances conspire as they did.
There is controversy about whether there was sufficient time for more effective emergency evacuation. The main problem was that most of the personnel who had the authority to order evacuation had been killed when the first explosion destroyed the control room. This was a consequence of the platform design, including the absence of blast walls. Another contributing factor was that the nearby connected platforms Tartan and Claymore continued to pump gas and oil to Piper Alpha until its pipeline ruptured in the heat in the second explosion. Their operations crews did not believe they had authority to shut off production, even though they could see that Piper Alpha was burning. The nearby diving support vessel Lowland Cavalier reported the initial explosion just before 22:00, and the second explosion occurred twenty two minutes later. By the time civil and military rescue helicopters reached the scene, flames over one hundred metres in height and visible as far as one hundred km (120 km from the Maersk Highlander) away prevented safe approach. Tharos, a specialist firefighting vessel, was able to approach the platform, but could not prevent the rupture of the Tartan pipeline, about two hours after the start of the disaster, and it was forced to retreat due to the intensity of the fire. The blazing remains of the platform were eventually extinguished three weeks later by a team led by famed firefighter Red Adair, despite reported conditions of 80 mph (130 km/h) winds and 70-foot (20 m) waves. The part of the platform which contained the galley where about 100 victims had taken refuge was recovered in late 1988 from the sea bed, and the bodies of 87 men were found inside.
- On 7/6/1988, a series of explosions and fires destroyed the Piper Alpha oil platform - 165 platform workers and 2 emergency responders were killed - 61 workers survived by jumping into the North Sea
- It is believed that a pump had been...