Mexico City
14th November 1984
Boiling liquid expanding vapour explosion (BLEVE) at LPG terminal. 500 killed.
Plant was being filled from refinery 400km away. Drop in pressure noticed incontrol room & at pumping station. Pipe had ruptured.
Operators’ could not identify cause of pressure drop, as they had no gasdetection equipment. No emergency shutdown at that stage and release ofLPG continued for about 5-10 minutes, when gas cloud drifted to flare stack.
Causal analysis – failure of overall basis for safety, including layout of plantand emergency isolation features. Fire water system was disabled in initialblast. Inadequate water spray systems did not keep remaining storage vesselscool and failed to prevent spread of fire from vessel to vessel. Plant had nogas detection system and therefore when isolation system was initiated it wasprobably too late. Installation of more effective gas detection and emergencyisolation system could have averted incident. Traffic chaos as residents triedto escape area hindered arrival of emergency services.
Brent CrossCrane Collapse
20th June 1964
Material failure due to overloading. Fell onto coach – 7 died.
Causal analysis - crane modified incorrectly
Human factors – errors in manufacturing and maintainingcrane. Safe working load indicator inoperative. Lugsmanufactured to wrong spec, recognised during manufacturebut no check against drawings. Inspection revealed deviationbut inspector did not want to reject something passed byparent company. Weekly inspection not carried out inpresence of operator and defective safe working loadindicator undetected. Records of inspection not completed byinspector but probably by someone retrospectively with thewords “good order against” safe load indicator.
Markham Colliery
30th July 1973
Material failure to fatigue. Riding cage fell to pitbottom. 18 died, 11 injured.
Causal analysis – Braking system suffered from afatigue crack. Dirt in bearing braking rod resulted init being bent. Brake supposed to be failsafe.
Human factors – Braking system had not beeninspected for about 10 years prior to accident.Information on fatigue had been found at anothercolliery but not passed on. Poor design of brakingsystem.
![C:\Users\Mike\Pictures\Thumb635x353[1].jpg](data/images/img3.jpg)
Flixborough Exposion
1st June 1974
Explosion caused by poor change management. 28 died.
Causal analysis – failure of pipe leading to release of chemical cloudthat ignited.
Management deficiencies – inadequate procedures involving plantmodifications. Engineers had no special expertise in high pressurepipework & no proper drawings. Process with large amount ofhydrocarbons under pressure above flashpoint installed in area thatcould expose many to severe hazard.
Human factors – Primarily weak management. Individuals overworkedand liable to error. “There was no mechanical engineer on site ofsufficient qualification, status or authority to deal with complex andnovel engineering problems and insist on necessary measures beingtaken.”
Littlebrook “D” Power Station
9th January 1978
Material failure due to corrosion. Suspension cable on riding cagefailed. Hoist operated by contractor. 4 died.
Causal analysis – Suspension cable broke at point weakened bycorrosion and devoid of lubricant. Corrosion happened over shortperiod so not detected. Water in shaft contained salt, adding tocorrosion. Safety system did not operate as clamping mechanisms alsocorroded.
Human factors – need for stringent maintenance standards notrecognised by staff or management. Statutory 6-monthly inspectionsoverdue. Weekly inspections failed to see defects. Cage carrying morethan recommended number of passengers. Maintenance records notwell kept and exact regime could not be determined. Lack of clearpolicies and procedures for contractor.
BP Grangemouth
22nd March 1987
Explosion at “hydrocracker” unit. 1 killed.
Causal analysis – air operated control valve on high-pressure separatorhad been opened and closed manually. Liquid level fell and the valve wasopened, allowing remaining liquid in separator to drain away and for high-pressure gas to break through into low-pressure separator and vesselexploded.
Human factors – control valve did not close automatically as the extra-lowtrip on the high-pressure separator had been disconnected several yearsearlier, operators assuming that these were no longer needed and trainingreflected this. Operators did not trust main level control reading andreferred to a chart recorder for back up level reading; there was an offseton this recorder which led them to assume the level in the high-pressureseparator was normal. Pressure relief had been designed for fire relief notgas breakthrough. There was excessive reliance on operators withinadequate appreciation of risks associated with gas breakthrough.
Allied Colloids
21st July 1992
Fire and explosion at raw materials warehouse. Fire spread to adjacentwarehouses and an external chemical drum store. Damage only.
Causal analysis – one of the stores (intended for storing frost sensitiveproducts) had steam heated blowers turned on to dry out moisture. Heatingcaused some kegs to rupture and spill powder on floor. The alarm was raisedwhen an employee thought it was smoke. After determining there was noimmediate hazard the MSDS was consulted for spillage arrangements andcleanup devised. An exothermic reaction was caused when the kegs’ contentsmixed, leading to ignition, explosion and major fire.
Human factors – The wrong classification of substances leading to storage ofincompatible chemicals together. Operator error (or failure of heating system)meant heating was applied to store in addition to main warehouse. Lack ofappropriate spillage training and procedures. Lack of management to ensureappropriate fire detection and fire fighting facilities – fire brigade not notifieduntil 50 minutes after initial incident.
Windsor Castle
20th October 1992
Fire. Damage only.
Causal analysis – heat of a high-powered spotlight igniteda curtain. Fire spread quickly, venting itself through theroof.
In the post-fire investigations it was discovered that therapid spread of fire was due to the lack of fire stopping incavities and roof voids, allowing the fire free reign of thebuilding. This matter was specifically addressed in therestoration project, and fire breaks were placed into thevoid to avoid a similar disaster happening in future
Hickson & Welch
21st September 1992
Fire and explosion at factory batch still. 5 killed.
Causal analysis – still base cleaned out for first time in 30 years. Heatwas applied to soften sludge.
Human factors – decision to clean out still base with no prior testingof residue and atmosphere in vessel. Lack of communicationbetween operatives & management. Absence of policies &procedures. Failure to blank off still base inlet before work started.Presence of building materials in control room impeding escape.Inward opening door in control room. Holes in brickwork above falseceiling of protected route allowing smoke ingress into toilets whereone victim was found. Inadequate permit to work systems
Port of Ramsgate
14th September 1994
Collapse of passenger walkway. 6 killed.
Causal analysis – failure of a weld in a safety criticalsupport element. Design deficiencies.
Human factors – no provision for ongoing maintenance.Design deficiencies ignored by all interested parties;important environmental considerations not addressed.Lack of liaison between classification society anddesigner/installer in Sweden.
Note – Swedish design/install company refused to payfine.
Albright and Wilson
3rd October 1996
Fire and explosion at chemical storage site at AvonmouthDamage only.
Causal analysis – tanker believed to contain epichlorohydrinoff-loaded. Later found to contain sodium chlorite, whichreacts explosively with epichlorohydrin.
Human factors – No check of documentation carried by driverwhich would have shown contents of tanker. No preventativemeasures in place to safeguard against addition of materialreactive with substance already in storage tank. No rawmaterial control/sampling or operating procedures,particularly for receipt of materials.
Buncefield Oil Depot
11th December 2005
Fire and explosion. Damage only.
Causal analysis – pumping of too much fuel intostorage vessel. Automatic level gauge recordedunchanged level despite continued pumping. Richfuel vapour formed around bund, ignited byunknown source.
Human factors – reliance on automated systemswhich did not activate. Failure of COMAHprocedures.
Imperial Sugar
7th February 2008
Dust explosion at sugar factory, Georgia. 14 killed.
Causal analysis – sugar dust in enclosed conveyor belt likely ignitedby overheated bearing.
Human factors – conveying equipment not deigned or maintainedto minimise release of sugar dust, nor were there explosion reliefvents. Dust could easily accumulate, and inadequate housekeepingresulted in considerable accumulation of combustible dust onfloors and elevated surfaces throughout packing building. Previoussugar fires, similarly caused, although none had caused explosionor major fire, did not result in managers or workers recognisinghazards posed by sugar dust accumulation: danger had been knownabout as far back as 1925.
Banbury-Seer Green
11th December 1981
Rail crash caused by human failure. 3 killed.
Inexperienced signalman at Gerrards Cross miss-read or failed tocomprehend indication on signal diagram; proceeded on assumption thatlocked signal lever was frozen, and track circuit reading that line wasunclear was activated by fallen branch from passing stock train, which infact was stationary.
Driver of passenger train travelling too fast for conditions after beingspecifically warned to take care and to travel between 5-10mph.Estimated speed was 35mph. Was given authorisation to pass dangersignal- communication between driver and signalman may have beenambiguous and led to driver believing situation was not serious.
Driver and Guard of stock train failed to provide detonator protection torear of train, but may not have had time before accident occurred.
