Piper Alpha
Piper Alpha was a North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...

 oil production platform
Oil platform
An oil platform, also referred to as an offshore platform or, somewhat incorrectly, oil rig, is a lаrge structure with facilities to drill wells, to extract and process oil and natural gas, and to temporarily store product until it can be brought to shore for refining and marketing...

 operated by Occidental Petroleum (Caledonia) Ltd
Occidental Petroleum
Occidental Petroleum Corporation is a California-based oil and gas exploration and production company with operations in the United States, the Middle East, North Africa, and South America...

. The platform began production in 1976, first as an oil platform and then later converted to gas production. An explosion and resulting fire destroyed it on 6 July 1988, killing 167 men, with only 61 survivors. The death toll includes two crewmen of a rescue vessel. Total insured loss was about £1.7 billion (US$3.4 billion). At the time of the disaster the platform accounted for approximately ten percent of North Sea oil
North Sea oil
North Sea oil is a mixture of hydrocarbons, comprising liquid oil and natural gas, produced from oil reservoirs beneath the North Sea.In the oil industry, the term "North Sea" often includes areas such as the Norwegian Sea and the area known as "West of Shetland", "the Atlantic Frontier" or "the...

 and gas production, and was the worst offshore oil disaster in terms of lives lost and industry impact.

The Kirk of St Nicholas in Union Street, Aberdeen
Aberdeen is Scotland's third most populous city, one of Scotland's 32 local government council areas and the United Kingdom's 25th most populous city, with an official population estimate of ....

 has dedicated a chapel in memory of those who perished and there is a memorial sculpture in the Rose Garden of Hazlehead Park
Hazlehead Park
Hazlehead Park is a large public park in the Hazlehead area of Aberdeen, Scotland. 180 hectares in size, it was opened to the public in 1920, having formerly been the estate of Hazlehead House, home of William Rose, shipbuilder....

 in Aberdeen. Thirty bodies were not recovered.

Piper oil field

Four companies that later transformed into the OPCAL joint venture obtained an oil exploration licence in 1972 and discovered the Piper oilfield
Piper oilfield
The Piper oilfield is a substantial North Sea oilfield. Oil extracted from it is piped to Scotland, where it is refined at a purpose built refinery on the island of Flotta, in the Orkney Islands....

 located at 58°28′N 0°15′E in early 1973 and commenced fabrication of the platform, pipelines and onshore support structures. Oil production started in 1976 with about 250000 barrels (39,746.8 m³) of oil per day increasing to 300000 barrels (47,696.2 m³). A gas recovery module was installed by 1980. Production declined to 125000 barrels (19,873.4 m³) by 1988. OPCAL built the Flotta
Flotta is a small island in Orkney, Scotland, lying in Scapa Flow. The island is known for its large oil terminal and is linked by Orkney Ferries to Houton on the Orkney Mainland and Lyness and Longhope on Hoy....

 oil terminal in the Orkney Islands
Orkney Islands
Orkney also known as the Orkney Islands , is an archipelago in northern Scotland, situated north of the coast of Caithness...

 to receive and process oil from the fields Piper, Claymore and Tartan, each with its own platform. One thirty inch (0.762 m) diameter main oil pipeline ran 128 miles (206 kilometres) from Piper Alpha to Flotta, with a short oil pipeline from the Claymore platform joining it some twenty miles (32 km) to the west. The Tartan field also fed oil to Claymore and then onto the main line to Flotta. Separate 46 cm diameter gas pipelines run from Piper to the Tartan platform, and from Piper to the gas compressing platform MCP-01 some 30 miles (48.3 km) to the northwest.


A large fixed platform, Piper Alpha was situated on the Piper oilfield, approximately 120 miles (193 km) northeast of Aberdeen
Aberdeen is Scotland's third most populous city, one of Scotland's 32 local government council areas and the United Kingdom's 25th most populous city, with an official population estimate of ....

 in 474 feet (144 m) of water, and comprised four modules separated by firewalls.
The platform was constructed by McDermott Engineering at Ardersier
Ardersier is a small former fishing village in the Scottish Highlands, on the Moray Firth, east of Inverness, near Fort George, and Nairn . Its name is an anglicisation of the Gaelic "Àird nan Saor", or "Headland of the joiners", one local legend being that carpenters working on the construction...

 and UIE at Cherbourg, with the sections united at Ardersier before tow out during 1975, with production commencing in late 1976.
For safety reasons the modules were organised so that the most dangerous operations were distant from the personnel areas. The conversion from oil to gas broke this safety concept, with the result that sensitive areas were brought together, for example, the gas compression next to the control room, which played a role in the accident. It produced crude oil and natural gas
Natural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...

 from 24 well
Oil well
An oil well is a general term for any boring through the earth's surface that is designed to find and acquire petroleum oil hydrocarbons. Usually some natural gas is produced along with the oil. A well that is designed to produce mainly or only gas may be termed a gas well.-History:The earliest...

s for delivery to the Flotta oil terminal on Orkney and to other installations by three separate pipeline
Pipeline transport
Pipeline transport is the transportation of goods through a pipe. Most commonly, liquids and gases are sent, but pneumatic tubes that transport solid capsules using compressed air are also used....

s. It has been said that at the time of the disaster, Piper was one of the heaviest platforms (along with Magnus
Magnus oilfield
The Magnus oilfield is a large oilfield in the United Kingdom's zone of North Sea. It is located north-east of the Shetland Islands. The field is located mainly in Block 211/12a. Resources are estimated to total of oil, of which are recoverable reserves....

 and Brae B
Miller oilfield
The Miller oilfield is a deep reservoir under the North Sea, 240 kilometres northeast of Peterhead in UKCS Blocks 16/7b and 16/8b. It was discovered in 1982 by BP in a water depth of 100 metres. Production from Miller field started in June 1992, and plateau production was from late 1992 to 1997 at...

) operating in the North Sea.

Timeline of the incident

A new gas pipeline was built in the weeks before the 6 July explosion, and while this work disrupted the normal routine, the platform was operating as normal. The discovery of a small gas leak was not unusual and no cause for concern. 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.

12:00 p.m.
Two condensate pumps, designated A and B, displaced the platform's condensate for transport to the coast. On the morning of July 6, Pump A's pressure safety valve (PSV #504) was removed for routine maintenance. The pump's fortnightly overhaul was planned but had not started. The open condensate pipe was temporarily sealed with a blind flange
A flange is an external or internal ridge, or rim , for strength, as the flange of an iron beam such as an I-beam or a T-beam; or for attachment to another object, as the flange on the end of a pipe, steam cylinder, etc., or on the lens mount of a camera; or for a flange of a rail car or tram wheel...

 (flat metal disc). Because the work could not be completed by 6:00 p.m., the blind flange remained in place. The on-duty engineer filled out a permit which stated that Pump A was not ready and must not be switched on under any circumstances.

6:00 p.m.
The day shift ended, and the night shift started with 62 men running Piper Alpha. As he found the on-duty custodian busy, the engineer neglected to inform him of the condition of Pump A. Instead he placed the permit in the control centre and left. This permit disappeared and was not found. Coincidentally there was another permit issued for the general overhaul of Pump A that had not yet begun.

7:00 p.m.
Like many other offshore platforms, Piper Alpha had an automatic fire-fighting system, driven by both diesel and electric pumps (the latter were disabled by the initial explosions). The diesel pumps were designed to suck in large amounts of sea water for fire fighting; the pumps had an automatic control to start them in case of fire. However, the fire-fighting system was under manual control on the evening of 6 July: Piper Alpha procedures required manual control of the pumps whenever divers were in the water (as they were for approximately 12 hours a day during summer) regardless of their location, to prevent divers from being sucked in with the sea water (fire pumps on other platforms were switched to manual control only if the divers were close to the inlet).

9:45 p.m.
Condensate (natural gas liquids NGL) Pump B stopped suddenly and could not be restarted. As the entire power supply of the offshore construction work depended on this pump, the manager had only a few minutes to bring the pump back online, otherwise the power supply would fail completely. A search was made through the documents to determine whether Condensate Pump A could be started.

9:52 p.m.
The permit for the overhaul was found, but not the other permit stating that the pump must not be started under any circumstances due to the missing safety valve. The valve was in a different location from the pump and therefore the permits were stored in different boxes, as they were sorted by location. None of those present was aware that a vital part of the machine had been removed. The manager assumed from the existing documents that it would be safe to start Pump A. The missing valve was not noticed by anyone, particularly as the metal disc replacing the safety valve was several metres above ground level and obscured by machinery.

9:55 p.m.
Condensate Pump A was switched on. Gas flowed into the pump, and because of the missing safety valve, produced an overpressure which the loosely fitted metal disc did not withstand.

Gas audibly leaked out at high pressure, drawing the attention of several men and triggering six gas alarms including the high level gas alarm, but before anyone could act, the gas ignited and exploded, blowing through the firewall made up of 2.5 x 1.5 metre panels bolted together, which were not designed to withstand explosions. The custodian pressed the emergency stop button, closing huge valves in the sea lines and ceasing all oil and gas production.

Theoretically, the platform would then have been isolated from the flow of oil and gas and the fire contained. However, because the platform was originally built for oil, the firewalls were designed to resist fire rather than withstand explosions. The first explosion broke the firewall and dislodged panels around Module (B). One of the flying panels ruptured a small condensate pipe, creating another fire.

10:04 p.m.
The control room was abandoned. Piper Alpha's design made no allowances for the destruction of the control room, and the platform's organisation disintegrated. No attempt was made to use loudspeakers or to order an evacuation.

Emergency procedures instructed personnel to make their way to lifeboat stations, but the fire prevented them from doing so. Instead the men moved to the fireproofed accommodation block beneath the helicopter deck to await further instructions. Wind, fire and smoke prevented helicopter landings and no further instructions were given, with smoke beginning to penetrate the personnel block.

As the crisis mounted, two men donned protective gear in an attempt to reach the diesel pumping machinery below decks and activate the firefighting system. They were never seen again.

The fire would have burnt out were it not being fed with oil from both Tartan and the Claymore platforms, the resulting back pressure forcing fresh fuel out of ruptured pipework on Piper, directly into the heart of the fire. The Claymore continued pumping until the second explosion because the manager had no permission from the Occidental control centre to shut down. Also, the connecting pipeline to Tartan continued to pump, as its manager had been directed by his superior. The reason for this procedure was the exorbitant cost of such a shut down. It would have taken several days to restart production after a stop, with substantial financial consequences.

Gas lines of 140 to 146 cm in diameter ran to Piper Alpha. Two years earlier Occidental management ordered a study, the results of which warned of the dangers of these gas lines. Due to their length and diameter it would have taken several hours to reduce their pressure, so that it would not have been possible to fight a fire fuelled by them. Although the management admitted how devastating a gas explosion would be, Claymore and Tartan were not switched off with the first emergency call.

10:20 p.m.
Tartan's gas line (pressurised to 120 Atmospheres) melted and burst, releasing 15-30 tonnes of gas every second, which immediately ignited. A massive fireball 150 metres in diameter engulfed Piper Alpha, killing two crewmen on a fast rescue boat launched from the standby vessel Sandhaven and the six Piper Alpha crewmen they had rescued from the water. From that moment on, the platform's destruction was assured.

10:30 p.m.
The Tharos
Transocean Marianas is an Earl & Wright Sedco 700 design semi-submersible drilling unit capable of operating in harsh environments and water depths up to using an , 15,000 psi blowout preventer , and a outside diameter marine riser....

, a large semi-submersible
A semi-submersible is a specialised marine vessel with good stability and seakeeping characteristics. The semi-submersible vessel design is commonly used in a number of specific offshore roles such as for offshore drilling rigs, safety vessels, oil production platforms and heavy lift cranes.The...

 fire fighting, rescue and accommodation vessel, drew alongside Piper Alpha. The Tharos used its water cannons where it could, but it was restricted, because the cannons were so powerful they would injure or kill anyone hit by the water.

10:50 p.m.
The second gas line ruptured, spilling millions of litres of gas into the conflagration. Huge flames shot over 300 ft (91.4 m) in the air. The Tharos was driven off by the fearsome heat, which began to melt the surrounding machinery and steelwork. It was only after this second explosion that the Claymore stopped pumping oil. Personnel still left alive were either desperately sheltering in the scorched, smoke-filled accommodation block or leaping from the deck some 200 ft (61 m) into the North Sea.

11:20 p.m.
The pipeline connecting Piper Alpha to the Claymore Platform burst.

11:50 p.m.
The generation and utilities Module (D), which included the fireproofed accommodation block, slipped into the sea. The largest part of the platform followed it.

12:45 a.m., 7 July
The entire platform had gone. Module (A) was all that remained of Piper Alpha.

At the time of the disaster 224 people were on the platform; 165 died and 59 survived. Two men from the Standby Vessel Sandhaven were also killed.


There is controversy about whether there was sufficient time for more effective emergency evacuation
Emergency evacuation
Emergency evacuation is the immediate and rapid movement of people away from the threat or actual occurrence of a hazard. Examples range from the small scale evacuation of a building due to a bomb threat or fire to the large scale evacuation of a district because of a flood, bombardment or...

. 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
Transocean Marianas is an Earl & Wright Sedco 700 design semi-submersible drilling unit capable of operating in harsh environments and water depths up to using an , 15,000 psi blowout preventer , and a outside diameter marine riser....

, 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.
Two crewmen from the standby vessel MV Sandhaven Fast Rescue Craft were killed when an explosion on the platform destroyed their Fast Rescue Craft; the survivor Ian Letham later received the George Medal
George Medal
The George Medal is the second level civil decoration of the United Kingdom and Commonwealth.The GM was instituted on 24 September 1940 by King George VI. At this time, during the height of The Blitz, there was a strong desire to reward the many acts of civilian courage...

. The largest number of survivors (37 out of 59) were recovered by the Fast Rescue Craft MV Silver Pit; coxswain James Clark later received the George Medal. Others awarded the George Medal were Charles Haffey from Methil, Andrew Kiloh from Aberdeen, and James McNeill from Oban.

The blazing remains of the platform were eventually extinguished three weeks later by a team led by famed firefighter Red Adair
Red Adair
Paul Neal "Red" Adair was an American oil well firefighter. He became world notable as an innovator in the highly specialized and extremely hazardous profession of extinguishing and capping blazing, erupting oil well blowouts, both land-based and offshore.-Life and career:Adair was born in...

, despite reported conditions of 80 mi/h winds and 70 feet (21.3 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.

Legacy of accident

The Cullen Inquiry was set up in November 1988 to establish the cause of the disaster. In November 1990, it concluded that the initial condensate leak was the result of maintenance work being carried out simultaneously on a pump and related safety valve
Safety valve
A safety valve is a valve mechanism for the automatic release of a substance from a boiler, pressure vessel, or other system when the pressure or temperature exceeds preset limits....

. The inquiry was critical of Piper Alpha's operator, Occidental, which was found guilty of having inadequate maintenance and safety procedures. But no criminal charges were ever brought against it.

The second phase of the enquiry made 106 recommendations for changes to North Sea safety procedures, all of which were accepted by industry. Most significant of these recommendations was that the responsibility for enforcing safety in the North Sea should be moved from the Department of Energy
Department of Energy (United Kingdom)
The Department of Energy was a department of the United Kingdom Government. The Department was established in January 1974, when the responsibility for energy production was transferred away from the Department of Trade and Industry in the wake of the 1973 oil crisis and with the importance of...

 to the Health and Safety Executive
Health and Safety Executive
The Health and Safety Executive is a non-departmental public body in the United Kingdom. It is the body responsible for the encouragement, regulation and enforcement of workplace health, safety and welfare, and for research into occupational risks in England and Wales and Scotland...

, as having both production and safety overseen by the same agency was a conflict of interest.

The disaster led to insurance claims of around US$ 1.4 billion, making it at that time the largest insured man-made catastrophe. The insurance and reinsurance claims process revealed serious weaknesses in the way insurers at Lloyd's of London
Lloyd's of London
Lloyd's, also known as Lloyd's of London, is a British insurance and reinsurance market. It serves as a partially mutualised marketplace where multiple financial backers, underwriters, or members, whether individuals or corporations, come together to pool and spread risk...

 and elsewhere kept track of their potential exposures, and led to their procedures being reformed.

Survivors and relatives of those who died went on to form the Piper Alpha Families and Survivors Association, which campaigns on North Sea safety issues.

The wreck buoy marking the remains of the Piper is approximately 120 metres from the south-east corner of the replacement Piper Bravo
Piper Bravo
The Piper Bravo is a North Sea oil production platform originally operated by Occidental Petroleum Ltd. It was built to replace the Piper Alpha platform, which was destroyed by a fire and subsequent series of explosions in 1988...

 platform. A lasting effect of the Piper Alpha disaster was the establishment of Britain's first "post-Margaret Thatcher
Margaret Thatcher
Margaret Hilda Thatcher, Baroness Thatcher, was Prime Minister of the United Kingdom from 1979 to 1990...

" trade union, the Offshore Industry Liaison Committee
Offshore Industry Liaison Committee
The Offshore Industry Liaison Committee was a trade union set up in the United Kingdom in response to the deaths of 167 workers on the Piper Alpha platform on July 6, 1988...


A memorial sculpture, showing three oil workers, can be found in the Rose Garden within Hazlehead Park in Aberdeen. The sculptor is Sue Jane Taylor, the Scottish artist who had visited the Piper platform the previous year, and based much of her work around what she saw in and around the oil industry.

In 2008, to mark the 20th anniversary of the disaster, a stage play, Lest We Forget was commissioned by Aberdeen Performing Arts
Aberdeen Performing Arts
Aberdeen Performing Arts is a company set up in 2005 to manage the running of His Majesty's Theatre, The Music Hall and Aberdeen Box office in Aberdeen, Scotland. The buildings are still owned by Aberdeen City Council. Since 2008, they now also manage The Lemon Tree after its brief closure....

 and written by playwright Mike Gibb . It was performed in Aberdeen, Scotland in the week leading up to the anniversary with the final performance on 6 July 2008, twenty years to the day.

Beginning in 1998, one month after the tenth anniversary, Professor David Alexander, director of the Aberdeen Centre for Trauma Research at Robert Gordon University
Robert Gordon University
Robert Gordon University is located in Aberdeen, Scotland. Building on over 250 years involvement in education, it was granted university status in 1992. Robert Gordon University currently has approximately 16,407 students at its two campuses at Garthdee and the City Centre, studying on over 145...

 carried out a study into the long-term psychological and social effects of Piper Alpha. He managed to find thirty-six 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 behavioral symptoms of post traumatic stress disorder. Twenty-eight said they had difficulty in finding employment following the disaster; it appears that some offshore employers 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 survived victims also reported various psychological and social problems. Alexander also wrote that "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."

See also

  • National Geographic Seconds From Disaster episodes
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