Flixborough disaster
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The Flixborough disaster was an explosion at a chemical plant close to Flixborough (near Scunthorpe), North Lincolnshire, England, on 1 June 1974. It killed 28 people and seriously injured 36.
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[edit] Background
The chemical plant, owned by Nypro (UK) and in operation since 1967, produced caprolactam, a precursor chemical used in the manufacture of nylon. The process involved oxidation of cyclohexane with air in a series of six reactors to produce a mixture of cyclohexanol and cyclohexanone. Two months prior to the explosion, a crack was discovered in the number 5 reactor. It was decided to install a temporary 50 cm (20 inch) diameter pipe to bypass the leaking reactor to allow continued operation of the plant while repairs were made.
Residents of the village of Flixborough were not keen to have such a large industrial development so close to their homes and had expressed concern when the plant was first proposed.
[edit] The disaster
At 16:53 on Saturday 1 June 1974, the temporary bypass pipe (containing cyclohexane at 150°C (302°F) and 1 MPa) ruptured, possibly as a result of a fire on a nearby 8 inch (20 cm) pipe which had been burning for nearly an hour. Within a minute, about 40 tonnes of the plant's 400 tonne store of cyclohexane leaked from the pipe and formed a vapour cloud 100–200 metres (320-650 feet) in diameter. The cloud, on coming in contact with an ignition source (probably a furnace at a nearby hydrogen production plant) exploded, completely destroying the plant. Around 1,800 buildings within a mile radius of the site were damaged.
The fuel-air explosion was estimated to be equivalent to 15 tonnes of TNT (60 gigajoules) and it killed all 18 employees in the nearby control room. Nine other site workers were killed, and a delivery driver died of a heart attack in his cab. All the dead were adult males.
Observers have said that had the explosion occurred on a weekday, more than 500 plant employees would likely have been killed. Resulting fires raged in the area for over 10 days. Until the Hertfordshire Oil Storage Terminal Fire in 2005 it was Britain's biggest ever peacetime explosion.
Substantial destruction of property was recorded in Flixborough itself, as well as in the neighbouring villages of Burton-on-Stather and Amcotts. Significant structural damage affected Scunthorpe (eight miles away) and the blast was heard (and felt) twenty-five miles away in Grimsby.
Although the area was quite remote graphic images of the disaster were soon shown on television due to a Yorkshire Television film crew who had been covering the Appelby-Frodingham Gala in Scunthorpe that afternoon.
[edit] Consequences
The official inquiry into the accident determined that the bypass pipe had failed due to unforeseen lateral stresses in the pipe during a pressure surge. The bypass had been designed by engineers who were not experienced in high-pressure pipework, no plans had been produced or calculations produced, the pipe was not pressure-tested, and was mounted on temporary scaffolding poles that allowed the pipe to twist under pressure. These shortcomings led to a widespread public outcry over industrial plant safety, and significant tightening of the UK government's regulations covering hazardous industrial processes. See COMAH Regulations.
The plant was re-built, but due to a subsequent collapse in the price of nylon, it closed down a few years later and was demolished in 1981. The site today is home to the Flixborough Industrial Estate, occupied by various businesses.
The foundations of properties destroyed by the blast can still be found on land between the estate and the village. A memorial to those who died was erected in front of offices at the rebuilt site in 1977. Cast in bronze, it showed a number of mallards in flight landing on water: When the plant was closed the statue was moved to the pond at the parish church in Flixborough. During the night on New Years' Day 1984 the sculpture was stolen. It has never been recovered and those responsible for the crime have never been found.
The plinth it stood on, featuring a plaque listing all those who died that day, can still be found outside the church.
[edit] See also
- List of disasters
- List of United Kingdom disasters by death toll
- Health and Safety Executive
- 2005 Hertfordshire Oil Storage Terminal fire
