Piper Alpha

Four companies (Occidental Petroleum (UK) Ltd, Getty Oil International (England) Ltd, Allied Chemical (Great Britain) Ltd, and Thomson Scottish Associates Ltd) formed a joint venture and obtained an oil-exploration licence in 1972. They discovered the Piper oilfield located at in January 1973, and began fabrication of the platform, pipelines, and onshore support structures. Oil production started in December 1976, less than four years after discovery (a record rarely beaten ever since), with about of oil per day, later increasing to . Separate diameter gas pipelines were run from the Tartan platform to Piper, and from Piper to the Total-operated The inventory of the pipelines was significant, with the main oil line to Flotta containing around 70,000 tonnes of oil and the three gas lines linking Piper to the surrounding platforms close to 2,000 tonnes of high-pressure gas. The pressure in the Tartan–Piper and Piper–MCP-01 pipelines was around 127 bar. ==Construction and layout==

Piper Alpha's production facilities were designed by Bechtel in London. The supporting platform jacket, as well as the topside module structures and buildings, were designed by McDermott Hudson. The eight-legged jacket structure was constructed by J. Ray McDermott in Ardersier, Inverness-shire, and Union Industrielle et d'Entreprise in Le Havre, France, with the sections united in Ardersier before being towed out during 1975. The jacket weighed around 14,000 tonnes and was tall, of which a length of was permanently submerged. Four clusters of foundation piles extended a further below the seabed. Topside modules weighing about 10,000 tonnes in aggregate were lifted from a crane ship and installed over the jacket in late 1976. Piper's hydrocarbon facilities and principal utilities were distributed in four main modules (A, B, C, and D) separated by firewalls and sitting atop the steel jacket. Above the main modules were a drilling derrick, various utilities, the living quarters, flare booms, two pedestal cranes, and the helideck. For safety reasons, the modules were organized so that the most dangerous platform operations took place far from the personnel areas. The hydrocarbon inventory actually held within the platform was small in comparison with that contained in the pipelines, standing at around 80 tonnes of process fluids and 160 tonnes of diesel fuel (which was stored in tanks located above module C). ==Upgrades and production modes==

In 1978, major works were carried out to enable the platform to meet British government gas-conservation requirements, and to avoid waste from the flaring of excess gas. A gas conservation module (GCM) was added, built on top of module B. After this work, Piper Alpha operated in what was known as "phase-2 mode", i.e., using the GCM facility. In phase-2 mode, the GCM would treat the gas obtained in the crude oil separation process, separate condensate (or natural gas liquids, NGL) from it, reinject the condensate in the oil export pipeline to Flotta, and compress the gas for export to the pipeline to MCP-01. From the end of 1980 until July 1988, phase-2 mode was its normal operating state. In the late 1980s, major construction, maintenance, and upgrade works were planned by Occidental, and by July 1988, the rig was already well into major revamp, with six projects identified, including the change-out of the GCM unit. This meant that the rig was returned to its initial "phase-1 mode", i.e., operating without the GCM unit, only three days before the accident. Despite the complex and demanding work schedule, Occidental made the decision to continue operating the platform in phase-1 mode throughout this period and not to shut it down, as had been originally planned. The planning and controls that were put in place were thought to be adequate. At the time of the accident, Piper weighed around 34,000 tonnes. It continued to export oil at just under per day (or 10% of the entire production of the UK sector of the North Sea, which made it the world’s single largest oil producer) and to export Tartan gas at some per day at standard conditions during this period. ==Events on 6 and 7 July 1988 ==

Because the platform was completely destroyed, and many of those involved died, analysis of events can only suggest a possible chain of events based on known facts. Some witnesses to the events question the official timeline. Preliminary events At 07:45, 6 July 1988, the permit-to-work forms for the day shift were issued and signed. Of the two condensate pumps, both located in module C, pump B was operating to displace the platform's condensate for transport to the coast, while pump A was due for maintenance. Two permits were issued to that effect, one for a pump overhaul and another for the removal of the pump's pressure safety valve (PSV #504), which was due for recertification. During the day, pump A was electrically and mechanically isolated, but containment was not broken. The PSV, instead, was removed. The open condensate pipe upstream of the PSV was temporarily sealed with a disk cover (a flat metal disc also called a blind flange or blank flange). It was hand-tightened only. Because the work could not be completed by 18:00, the blind flange remained in place. The on-duty engineer filled in information on the PSV removal permit to the effect that pump A was not ready and must not be switched on under any circumstances. However, this information was not provided in the pump overhaul permit. The night shift started at 18:00 with 62 men running Piper Alpha. As the on-duty custodian was busy, the engineer neglected to inform him of the condition of pump A. Instead, he placed the PSV permit in the control centre and left. This permit disappeared and was not found. At 21:45, condensate pump B stopped and could not be restarted. This was likely due to the formation of hydrates and the consequent blockage of gas compression pipework, following problems with the methanol system. The operators were anxious to reinstate condensate pumping capacity. Failure to do so would have meant needing to stop the gas compressors and venting to the flare all the gas that could not be processed. Around 21:55 a search was made through the documents to determine whether condensate pump A could be started. The permit for pump A overhaul was found but that for its PSV removal was not. The valve was at a distance from the pump, so the permits were stored in different boxes, as they were sorted by location. Because the overhaul had just started on that day, with no equipment removed or containment broken, the operators were under the impression that the pump could be put back in operation quickly and safely. None of those present were aware that a vital part of the machine had been removed. The missing valve was not noticed by anyone, particularly as the blind flange replacing the safety valve was several metres (yards) above deck level and obstructed from view. As a result, the control room was almost entirely destroyed. Panels around module B were also dislodged, with one of them rupturing a small condensate pipe, thus creating another fire. Personnel still left alive were either desperately sheltering in the scorched, smoke-filled accommodation block or leaping from the various deck levels, including the helideck, into the North Sea. The Claymore gas line ruptured at 23:20, adding even more fuel to the already massive jet fires on board Piper Alpha. At this point the Claymore OIM had received orders from Aberdeen to shut down production, and the gas flowline to Piper with it. He had initiated a pipeline blowdown (depressurization) but this was not yet complete at the moment of the rupture. Tartan's gas pipeline had been shut down around 22:30, with its blowdown commencing around 23:20. Around 23:45, with critical support structures failing from the intense heat, the platform began to collapse. One of the cranes fell first, followed by the drilling derrick. The generation and utilities module (D) and the fireproofed accommodation block, still occupied by crewmen who had sheltered there, then slipped into the North Sea. Some 80 men were in the block at the time. By 00:45, 7 July, almost all of Piper Alpha was gone, with only module A still standing. == Rescue operations ==

Nearby vessels and rescue craft Vessels that were close to Piper Alpha at the moment of the first explosion included MSV Tharos, a large semi-submersible firefighting, diving/rescue, and accommodation vessel; standby safety vessel MV Silver Pit, who immediately sent her fast rescue boat towards Piper; Maersk Cutter, which started dousing the drilling floor of Piper with her fire monitors as early as ten minutes after the blast; Lowland Cavalier, which had no monitors but immediately deployed a workboat; and converted supply ship Sandhaven, which was the standby vessel for Santa Fe 135, a semi-submersible drilling rig several miles away, and had her fast rescue craft in the water minutes after she spotted the first fire on Piper Alpha. Other vessels that attended the operation later were Loch Shuna, Maersk Logger and Maersk Leader. Overall, 11 fast rescue craft (FRC) from nearby vessels were involved in the rescue operations. Tharos launched her Sikorsky S-76 helicopter at 22:11 but it was unable to land on Piper due to smoke. At 22:23 Tharos received a message from Piper: "People majority in galley area. Tharos come. Gangway. Hoses. Getting bad." She drew alongside Piper Alpha around 22:30 and used her water cannon to cool the platform, which was useful in assisting survivors escape from the pipe deck and helideck. Attempts to deploy her extendable gangway over to Piper were unsuccessful. One survivor who jumped when the Tartan riser failed swam to Tharos and climbed out unaided. When the MCP-01 riser failed, Tharos withdrew to away. The MSV was equipped with a hospital with an offshore medic assisted by diver paramedics from a saturation diving team. A triage and reception area were set up on the vessel's helideck to receive injured casualties. Silver Pit's FRC was launched within two minutes of the first explosion and rescued the first nine people from the northwest corner within 13 minutes. She rescued a total of 29 people, with Silver Pit herself rescuing a further eight. When the Tartan riser failed Silver Pit withdrew to away. When the MCP-01 riser failed, rope on the deck began to smoulder and the vessel withdrew further away. Lowland Cavalier deployed a workboat that picked up two people who had fallen from a rope at the northwest corner. When the first gas riser failed, the workboat crew sheltered in the water. Sandhaven's FRC picked up four men who had climbed down ropes. She returned and picked up two more when the MCP-01 riser failed. At that moment, the craft's propeller got entangled in debris. The boat was engulfed in the fire, throwing the survivors and the three crew into the water. All perished with the exception of coxswain Iain Letham. The search-and-rescue helicopters made unsuccessful sweeps for survivors in the water and ferried injured survivors from rescue vessels to Tharos and to Aberdeen Royal Infirmary. A civilian Sikorsky S-61 of Bristow Helicopters carrying a medical emergency team arrived at the scene by 1:20 on 7 July. At 2:00 another helicopter landed on Tharos with the Offshore Specialist Team from Aberdeen Royal Infirmary, with a significant amount of medical equipment. The last survivors were picked up by Rescue 138 from Tharos at 7:25. By 8:15, 63 personnel (among whom one survivor who subsequently died and the surviving member of the crew of Sandhaven's FRC) had been brought ashore. Aircraft were used to search the area of the platform until the afternoon hours. == Casualties and survivors ==

At the time of the disaster, 226 people were on the platform; 165 died and 61 survived. Two men from Sandhaven were also killed in attempts to pick up survivors in a fast rescue boat. Of the 135 deceased whose bodies were recovered, the vast majority died from inhalation of smoke and gas, with only four indicating death from burning, and several others from injury sustained from jumping into the sea. The largest number of survivors (37 out of 61) were recovered by MV Silver Pit or her fast rescue boat, whose coxswain James Clark later received the George Medal, as did Iain Letham of the Sandhaven. Others awarded the George Medal were Charles Haffey from Methil, Andrew Kiloh from Aberdeen, and James McNeill from Oban. Sandhaven crewmates Malcolm Storey, from Alness, and Brian Batchelor, from Scunthorpe, were awarded George Medals posthumously. ==Aftermath==

Controversy exists about whether time was sufficient for a more effective emergency evacuation. Systems critical for emergency management such as the public announcement/general alarm, emergency power, safe haven, and—crucially—the lifeboats, were destroyed or impaired due to poor platform design. Executing the actions described in the emergency response plan became effectively impossible. Additionally, the OIM was perhaps not capable of thinking outside the established procedures and of ordering an improvised evacuation. It was estimated that the fires had produced flames with a height of about 200 metres and a peak rate of about 100 gigawatts, or three times the total power consumption of the United Kingdom. • The responsibility to implement was for 57 with the regulator, 40 for the operators, 8 for the industry as a whole and 1 for stand-by ship owners. The recommendations led to the enactment of the Offshore Safety Act 1992 and the making of the Offshore Installations (Safety Case) Regulations 1992. Most significant of these recommendations was that operators were required to present a safety case and that the responsibility for enforcing safety in exploitation operations in the part of the North Sea apportioned to the UK should be moved from the Department of Energy to the Health and Safety Executive, as having both production and safety overseen by the same agency was a conflict of interest. Civil suit Occidental and their insurers, Lloyd's of London, paid survivors and families of the dead a total of $220 million in settlements. Later, Lloyd's and Elf Enterprise Caledonia Ltd, successors to Occidental Petroleum, brought civil proceedings against a number of contractor companies who were working on Piper at the time of the accident. Based on the argument that the responsibility for the accident should be shared among the platform operator and the contractors working onboard immediately prior to the accident, Elf was seeking to recover from the defendants a part of the monies paid to the injured and the affected families. Among the companies involved were British Telecommunications, Wood Group, and Stena Offshore. Giving verdict in what was then the longest civil trial in Scottish history, in 1997 Lord Caplan ruled that two workers who were killed in the explosion, Robert Vernon (who had posthumously received the Queen's Commendation for Bravery) Lord Caplan found that Sutton had failed to tighten the bolts of the blind flange at the suction side of the removed PSV, and that Vernon had put the pump back in operation without checking its status first. Vernon was employed by Occidental and Sutton by contractor Score (UK) Ltd. The finding against Vernon and Sutton was controversial among the families of the victims. One of the 1997 rulings by Lord Caplan was that, albeit in principle contractors were obliged to indemnify Elf, Elf's insurers could not claim back monies from the defendant contractors, because Elf had already largely been indemnified by Lloyd's. Elf and Lloyd's appealed this finding in Scotland to the Inner House of the Court of Session, which decided in their favour in December 1999. Subsequently, the contractors appealed the decision to the House of Lords in London in November 2001, but their appeal was rejected. As a result, Elf and their insurers were able to recoup £136 million with accrued interest. ==Legacy==

The accident is the world's worst offshore oil and gas disaster in terms of lives lost. Only the 2010 Deepwater Horizon tragedy has caused a comparable impact in the industry. A lasting effect of the Piper Alpha disaster was the establishment of the Offshore Industry Liaison Committee, the trade union for oil and gas rig workers. The union, while still in the form of an unofficial committee drawn from different North Sea rigs, organized large strikes in the summers of 1989 and 1990. Piper Bravo was installed in 1992 to replace Alpha and commenced production in February 1993. A wreck buoy marking Alpha's remains was installed and lies approximately from Bravo. Beginning in 1998, one month after the 10th anniversary, professor David Alexander, director of the Aberdeen Centre for Trauma Research at Robert Gordon University carried out a study into the long-term psychological and social effects of Piper Alpha. He managed to find 36 survivors who agreed to give interviews or complete questionnaires. Almost all of this group reported psychological problems. More than 70% of those interviewed reported psychological and behavioural symptoms of post-traumatic stress disorder. Twenty-eight (or 78%) said they had difficulty in finding employment following the disaster; some offshore employers apparently regarded Piper Alpha survivors as "Jonahs" – bringers of bad luck, who would not be welcome on other rigs and platforms. The family members of the dead and surviving victims also reported various psychological and social problems. Alexander also stated, "some of these lads are stronger than before Piper. They've learned things about themselves, changed their values, some relationships became stronger. People realised they have strengths they didn't know they had. There was a lot of heroism took place." In process safety The Piper Alpha disaster and the Cullen Report are milestones in the development of process safety. Its effects on the offshore oil and gas industry can be compared with those the Flixborough disaster had on the onshore chemical and petroleum process industry in the 1970s. The Cullen Report put a strong emphasis on the importance of a robust safety management system (SMS). The requirement for a safety management system to be in place was introduced in British legislation in the wake of Piper Alpha. Elements of process safety management that failed on Piper Alpha included: • Permit-to-work, and in particular the mechanism of permit handover. The whole accident chain of events commenced due to the attempt to start-up a pump which was actually under maintenance. As a result of the tragedy, the Safety Case Regulations came into force in 1992. By late 1993, a safety case had to be submitted to the Health and Safety Executive for every platform and rig in British waters (including the exclusive economic zone). The safety case must describe and justify the design, inherent hazards and residual risk in the spirit of the ALARP (as low as reasonably practicable) principle, as well as the means of managing such residual risk. The safety case must be maintained up to date through the lifecycle of the installation. The safety case regime has been ascribed a measure of success in promoting safer facility design and management of offshore operations in the United Kingdom. Trade association Oil and Gas UK linked a significant fall in lost time injury frequency rate observed since 1997 to the introduction of the regime. A study commissioned by the Health and Safety executive found that the regime heightened awareness of risks throughout the industry and set in motion a more structured decision-making process targeting risk reduction efforts, safety management system improvements, and a better safety culture. According to another source, Piper was the catalyst for a development from an unsystematic, albeit well-meaning, collection of standards and processes to a systematized approach specific to safety. However, some criticism of the safety case approach has also been voiced, pointing to implementation and communication problems as well as issues with the supporting safety studies. The safety case regime has been adopted outside the United Kingdom, both as a regulatory instrument (for example in Australia, Malaysia, and Norway, In terms of facility design, some of the Cullen Report's recommendations have become tenets for the safe design of offshore oil and gas installations: The resulting changes in the design philosophy of offshore facilities have therefore been towards an inherently safer design (ISD) concept. Memorials , Aberdeen Parish Church, Aberdeen. The discs represent workers who died in the incident. At the window's base, the discs are orange/red in colour, signifying the fire. Their colour lightens in the upper part of the window, signifying their ascent to heaven A condolence banner was gifted in 1989 by the Victorian Trades Hall Council of Australia, and is now in the Aberdeen Maritime Museum. On 6 July 1991, the third anniversary of the disaster, a memorial sculpture was unveiled by the Queen Mother in the Rose Garden within Hazlehead Park in Aberdeen. It was created by Sue Jane Taylor, a Scottish sculptor who based much of her work around what she saw in and around the oil industry and had actually visited Piper Alpha in 1987. A memorial stone was erected in 1992 in Strathclyde Country Park to commemorate the men lost from that region. The Oil Chapel in the Kirk of St Nicholas, Aberdeen was dedicated in 1990 to mark 25 years of North Sea oil. The chapel hosts a book of remembrance to all those who have died offshore in British waters. In the media The incident was featured in the 1990 STV documentary television series Rescue, about the RAF Search and Rescue Force at RAF Lossiemouth, in the episode "Piper Alpha". Coincidentally, the film crew had been documenting the rescue teams at Lossiemouth at the time of accident and were able to accompany the helicopter during the Piper Alpha disaster, filming events as they happened from helicopter Rescue 138. In 1998, on the occasion of the 10th anniversary, Prospero Productions of Australia released the documentary Paying for the Piper. It was written and produced by Ed Punchard, who was one of the divers that managed to escape the inferno. The film follows Punchard's return to Scotland to confront his past and culminates in a meeting with Occidental officers. In 2004, National Geographic featured this incident in its Seconds from Disaster documentary as the episode "Explosion in the North Sea". On 6 July 2008, BBC Radio 3 broadcast a 90-minute play by Stephen Phelps entitled Piper Alpha. Based on the actual evidence given to the Cullen Inquiry, the events of that night were retold 20 years to the minute after they happened. Also in 2008, to mark the 20th anniversary of the disaster, a stage play, Lest We Forget was commissioned by Aberdeen Performing Arts and written by playwright Mike Gibb. It was performed in Aberdeen in the week leading up to the anniversary with the final performance on 6 July 2008, the 20th anniversary. In 2011, Lee Hutcheon produced and directed The Men of Piper Alpha, a documentary with several interviews to the survivors. In 2013, on the 25th anniversary of the disaster, the video Remembering Piper: The Night That Changed Our World was released by British offshore oil and gas industry initiative Step Change in Safety. It incorporates passages from the BBC radio play and artwork by Sue Jane Taylor. The documentary film Fire in the Night was also released in 2013. It was made by Berriff McGinty Films and co-produced by STV. Producer and cameraman Paul Berriff had been with Sea King Rescue 138 during the filming of the Rescue series. In 2017, the episode "Oil Rig Explosion" of the Smithsonian Channel documentary series Make It Out Alive! focused on the disaster, with interviews to, among others, Geoff Bollands, Iain Letham, Charles Haffey, and Paul Berriff. In 2018, a special edition of the Monopoly board game was released to commemorate the 30th anniversary of the tragedy. It was sponsored by a number of companies working in the North Sea offshore oil and gas industry, including majors such as Shell, whose Brent platforms substituted for the four train station squares. The game release was part of a fundraiser for the maintenance costs of the memorial in Hazlehead Park. The box lid prominently featured Piper Alpha imagery and a "Piper Alpha 30th Anniversary" title, which led the game to be referred to as the "Piper Alpha Monopoly". The reactions of some of the survivors and victims' families were negative, calling the game "callous" and a "sick joke". The game was re-released with a different design to clarify that it was really an oil-and-gas (and not a Piper Alpha-themed) Monopoly edition. Also in 2018, the disaster was featured on the History documentary series ''James Nesbitt's Disasters That Changed Britain''. Testimonials were heard from survivors and relatives of victims. In 2023, to mark the 35th anniversary, writer Mike Gibb adapted his stage play as a novel titled I Had Never Heard a City Cry Before, a quote from the script. In 2025, Disaster at Sea: The Piper Alpha Story, a three-part documentary, was broadcast on BBC Two. == See also ==