|Changes Following King's Cross Underground Fire Disaster in 1987|
Changes Following King's Cross Underground Fire Disaster in 1987
David A. Charters, Ph.D. | Fire Protection Engineering
"Shortly after the evening rush hour had passed its peak on Wednesday 18 November 1987 a fire of catastrophic proportions in the King's Cross Underground station claimed the lives of 30 people and injured many more. A further person was to die in hospital making the final death toll 31."
These are some of the opening words of the Investigation into the King's Cross Underground fire in London in the UK.1 The investigation called 150 witnesses, took 12 months to publish its findings, ran to more than 250 pages and made no less than 157 recommendations.
The fire started in the grease and detritus on the running tracks of an escalator and spread to the escalator's wooden skirting board. Although smoking was not allowed in underground stations, it is thought that a match was the cause of the fire.
The escalator's wooden decking and balustrades were preheated by the fire and, once ignited, the flames spread up the escalator trench and caused a flashover in the ticket hall. Evacuation of the lower levels of the station was underway at the time of the flashover, though unfortunately the escape route taken was up a separate set of escalators and through the ticket hall where the flashover occurred.
The changes in fire safety on London Underground were wide ranging and included:
In addition, existing building fire safety legislation was extended to cover underground stations.
The wider changes to fire safety were perhaps more subtle and far-reaching and included:
Awareness of the importance of fire dynamics was increased, and in particular the trench effect was discovered. When both balustrades and the floor of the escalator trench became involved in the fire, the flames, in entraining air on the up-hill side, lay down in the escalator trench. The trench effect was initially identified by researchers applying a (then) relatively new approach to fire modelling called Computational Fluid Dynamics. A similar effect had been observed before and is illustrated in An Introduction to Fire Dynamics.2
There was also a greater awareness of the importance of the reaction of fire of station and rolling stock linings and materials. Consequently, existing standards were further developed and continue to be enhanced, including standard test methods for toxicity testing.
The importance of human behavior in fire was also recognized. For example, some passengers did not act on instructions from station staff because they did not perceive them to be authoritative. This perception had developed during normal operation and has important implications for the training of staff. Other passengers responded to police officers who happened to be on the scene and used their initiative, but had little or no knowledge of the station or its emergency procedures.
Fire safety management, and in particular the importance of a safety culture, gained greater recognition. After the fire, there was a radically different approach to near-misses and internal inquiries into accidents were undertaken.
There was also a wider appreciation of the probabilistic nature of the risk of ignition and fire. London Underground had operated for over 100 years without a similar fire event, yet this did not necessarily mean that such a fire could not occur. Subsequently, the legislation for railways now requires a safety case informed by quantitative assessment of risk. The fire safety legislation for existing buildings is now also based on an assessment of risk.
Following the King's Cross fire, there have been major changes to fire safety on underground transport systems. Just as significantly, there have also been more subtle and far-reaching changes in the understanding of fire safety, and this can only have helped improve safety over the last 23 years and continues improving fire safety into the future.
David A. Charters is with BRE Global.