Piper Alpha is destroyed by fire and 167 lives are lost (LATENT FAILURES…
Piper Alpha is destroyed by fire and 167 lives are lost
Pump B causes explosion and Fire
Maintenance worker did not follow procedure to use wrench to tighten sleeve (HUMAN ERROR)
Possibly he was fatigued (Fossum, et al 2013)
Possible disregard for procedure (POOR SAFETY CULTURE MANAGEMENT FAILURE).
Pump B is brought online when it is out of service
Night shift found work permit but work had not begun on pump, they had no idea valve had been removed because work permit for valve was in different area of rig (POOR COMMUNICATION), (MANAGEMENT FAILURE), (Forneris, 2017)
Out of service valve is not in a visible position (DESIGN FAILURE). (Stone, 2004)
No feedback system to say valve was leaking (DESIGN FAILURE) (Stone, 2004)
No mechanism to lock out pump so it physically can not be started (DESIGN and PROCEDURE FAILURE) (Stone, 2004).
Condensate leak, eventually ignites/explodes
Fire barrier separating gas and oil areas shatters causing hole in oil pipeline
Barriers not designed for gas explosion (DESIGN FAILURE) Atropedia (2017)
Barriers had been built when rig was oil only (DESIGN FAILURE/FAILURE TO RETROFIT SUITABLE BARRIER)
Control room had to be evacuated after initial explosion
Control room should not have been beside higher risk gas (DESIGN FAILURE/FAILURE TO RETROFIT) (Stone, 2004).
No other area on rig designed to co ordinate an emergency (DESIGN FAILURE) (Stone, 2004).
Oil pipe catches fire creating black smoke
Flaming oil drips down onto grating that would allow oil to drop into ocean rather than gather fuel on solid grating (Bea, 2006).
Divers have placed rubber matting over grating to make it easier to walk on (PROCEDURE/MANAGEMENT FAILURE) (Workcover QLD, 2017).
Oil fie intensifies.
Auto fire suppression pumps have been switched to manual.
Pumps were always meant to be on auto, procedure changed so that pumps are on manual when divers are in the water (MANAGEMENT FAILURE) (Workcover QLD, 2017).
Pumps unable to be activated without control room intact (DESIGN FAILURE) (Stone, 2004).
Gas pipes burst and fire becomes catastrophic
First main gas line bursts creating massive fire
Gas is back feeding from Claymore and Tartan rigs
Claymore and Tartan do not shut down production because they do not have management approval (MANAGEMENT FAILURE) ((Workcover QLD, 2017).
Occidental managers do not want to cease production from Claymore and Tartan because of cost (MANAGEMENT FAILURE) (Workcover QLD, 2017).
Second pipeline bursts
Piper Alpha was originally designed for producing oil only. Gas is a by product of oil production and was burnt off.
According to NASA (2013) The U.K. government passes legislation that results in Piper Alpha having to process gas.
Piper Alpha is retrofitted to include gas production (LEGISLATIVE CHANGE)
Many of the contributing factors into the disaster were a result of Piper Alpha being retrofitted and not having controls put in at the design stage (DESIGN FAILURE). Fault tree analysis can help identify this according to Berk (2015)
Workers confused about plan of emergency action
Control room used as hub for emergencies
Control room is destroyed
Workers evacuate to accommodation block
Workers wait for evacuation, they are fearful
Smoke and fire prevent any rescue helicopters from landing (DESIGN FAILURE) (Stone, 2004).
No safe shelter for workers (DESIGN FAILURE) (Stone, 2004).
Workers could not access liferafts (DESIGN FAILURE). (Stone, 2004).
List of References
Atropedia, 2017, Piper alpha oil rig disaster, viewed 22 September 2017,
Bea, B 2006, Learning from failures: lessons from the recent history of failures of engineered systems, Centre for Catastrophic Risk Management, University of California, viewed 27 September 2017,
Berk, J 2015, System Failure Analysis, viewed 22 September 2017,
Forneris, J 2017, The effects of bad communication in business, viewed 27 September 2017,
Fossum, I & Bjorvatn, B & Waage, S & Pallesen, S 2013, Effects of shift and night work in the offshore petroleum industry: a systematic review, Industrial Health, viewed 22 September 2017,
NASA 2013, 'The north sea piper alpha disaster', NASA Safety Centre, viewed 18 September 2017,
Stone R, Tumer I & Stock, M 2004 ‘Linking product functionality to historic failures to improve failure analysis in design’, Research in Engineering Design, viewed 18 September 2017,
Stone, R Tumer I & Stock M, 2004 ‘Linking product functionality to historic failures to improve failure analysis in design’, Research in Engineering Design, viewed 15 August 2017,
Workcover QLD, 2017, Safety climate and safety culture, Workplace Health and Safety Electrical Safety Office Workers Compensation Regulator, viewed 27 September 2017,
According to Nasa (2013)-
Piper Alpha is an oil and gas production facility owned by Occidental Petroleum in the North Sea, 190 km from Aberdeen, Scotland.
Maintenance workers close down one of two condensate pumps but do not begin work on pump. Maintenance work order reflects that work on pump has not yet begun. A valve from the pipe further down the line from the pump is removed, a flange is put in place but the bolts are only hand tightened, a work permit is placed in the box near the valve with instructions to not operate.
On night shift one of the condensate pumps breaks down. The crew find the work permit for the pump stating that work has not yet begun and due to production commitments they decide to start the pump, they are unaware of the work permit on the valve because it is stored in a downstream section of the rig.
The condensate pump kicks in and quickly builds up pressure, the flange that has bolts that have only been hand tightened quickly leaks setting off gas monitors and resulting in a small fire and explosion.
The fire wall between the four modules that separate different production areas on the rig were designed when the rig was an oil only facility and were manufactured to withstand a fire, not an explosion.
As a result of the fire wall breaking up a small condensate pipe is ruptured and adds more fuel to the fire.
Two upstream oil rigs, Claymore and Tartan continue to pump gas, one of these pipes ruptures on Piper Alpha creating a massive fire, Claymore and Tartan continue to pump because of the costs involved with shutting down production.
Second pipe ruptures, Claymore shuts down gas production, Tartan is ordered to continue pumping as costs in stopping production are significant.
No emergency sirens or loudspeaker announcements are made, most workers make their way to the galley module which is fire proof and close to the helicopter pad.
Piper Alpha has automatic fire pumps but they are set to manual when divers are operating due to the risk of them being sucked into the underwater intake. They are never operated.
Helicopter evacuation of personnel is not possible due to fire and smoke, total of 167 people perish in disaster.
Poor safety culture
Poor design when rig was retrofitted to produce gas alongside oil
Management having production before safety attitude
Poor emergency procedures
Management making procedure changes without properly assessing risks.
No back up plan to manage emergency if control room destroyed
Maintenance worker not using wrench to tighten sleeve.
Poor work permit procedure whereby separate permits are issued and stored in different areas
Poor isolation procedure that resulted in pump being able to be operated with safety valve removed, pump should have been physically isolated
Fire barrier unable to withstand small gas explosion
Divers laying rubber matting on deck grating
Tartan and Claymore rigs not shutting down production immediately.