The Kings Cross Flashover 1987

                       NOT AN OFFICIAL LFCDA REPORT

Wednesday 18th November 1987                                                        

Kings Cross underground station is one of the busiest on London's 'tube' railway network serving over 100,000 passengers during peak hours. At approximately 7.32 pm on the evening of the fire, smoke was seen coming from one of the wooden escalators that was transporting passengers up from the platform levels to the ticketing hall. The London Fire Brigade dispatched 4 engines and an aerial ladder as the call was received at 7.36 pm and the first of these arrived on scene at 7.42pm. A team of firefighters went down from street level into the ticketing hall from where they could see a fire burning about 20 feet down the escalator shaft with four feet high flames emerging from the escalator stairs. At this stage there were still passengers exiting from the platforms below in an orderly manner.

As firefighters returned to street level to collect hose and breathing apparatus three officers remained in the ticketing hall to supervise the evacuation of passengers. Whilst two of them began a descent down towards the platforms to prevent further use of this escalator as an exit route, the senior officer - Station Officer Colin Townsley - remained in the ticketing hall at the top of the escalator shaft.

At 7.45pm the fire suddenly erupted up into the ticketing hall and created severe conditions likened to that of a flashover. At street level thick volumes of black smoke began to emerge from the station entrances and a large number of screaming passengers exited into the street. The fire burned for several hours killing 31 people including Soho's Station Officer Colin Townsley  who died trying  to rescue a woman from the blazing ticketing hall as the fire  suddenly erupted. Firefighters attempting to re-enter the ticketing hall to fight the fire likened the conditions as similar to climbing down into a volcano.

Flashover - Various theories were put forward as to what caused the ' flashover like' conditions as the fire suddenly erupted into the ticketing hall. In terms of scientific definition the event did not conform to the universal acceptance of what constitutes a 'flashover'. Consideration was given to the possibilty of an ignition of  fire gases that may have accumulated within the ticketing hall where such an event would be more closely accepted in definition to that of a 'backdraft'. Further thought was directed at the likelihood of the escalator fire being pushed upwards in the shaft by a 'piston effect' as trains arriving at platforms forced a major airflow out of the tunnels and up into the ticketing hall. However, mathematical modeling and computer simulations promoted a new theory of rapid fire development within inclined shafts with combustible surfaces termed trench effect.

It was established that once the trench effect became established, the 'piston effect' from trains would not have played an important role in the rapid  spread of the fire up the escalator and into the ticketing hall. This trench effect was seen to cause hot gases in the buoyant plume to lay along the escalator surface and create a rapid airflow which caused these gases to curl over and over towards the next steps above. The airflows in the trench increased in proportion to the size of the fire, eventually creating a flamethrower type effect up and into the ticketing hall.

Paul Grimwood was a fire investigator with the LONDON FIRE BRIGADE at the time of the fire and attended the incident as part of the official investigation team. The theories above were presented by scientists at the Harwell Laboratory and do not necessarily represent the official views of LONDON FIRE BRIGADE .

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