Eurotunnel protected by Water Mist
Published: 11 May, 2010
FOGTEC Fire Protection is equipping the Eurotunnel with its water mist fire fighting technology, making an important contribution to tunnel safety. The full-scale fire tests recently performed for this project have been the largest ever of their kind.
As a result of the fires in the Eurotunnel in 1996 and 2008 and their far reaching consequences, on 9 November 2009 the Eurotunnel operating company awarded the contract for equipping four so-called SAFE areas for the suppression of fires in the Eurotunnel to a consortium of specialised firms. The project will make use of the technology of the Cologne-based company FOGTEC. This technology consists of the so-called water mist systems that are used to fight fires by means of extremely small water droplets. The protection concept has been targeted especially at the protection of the wagons carrying lorries.
The Eurotunnel SAFE-Project is likely to attract a great deal of international attention. Jacques Gounon, Chairman of the Board of Directors of the Eurotunnel Group, commented: “Safety is the number one priority at Eurotunnel. That is why we are constantly innovating and continue to maintain a high level of investment in this area. The new SAFE stations, with no equivalent in the world, complete the many safety installations and equipments already in place.”
The managing director of FOGTEC, Dirk K. Sprakel, confirms: “The SAFE-Project is a milestone for fire protection in railway tunnels. It helps to increase safety, to reduce the investment and operating costs and to minimise shutdown times.“
Eurotunnel’s decision is the result of several years of investigations into an optimal concept for the protection of tunnels. The concept now developed foresees that trains will move immediately into one of four ‘SAFE-Stations’, of 900m in length each, after a fire has been detected. At this station, the wagons are checked within a very short time to detect where fire has developed. This is done by a sensor system based on fibre optic cables specifically developed for that purpose by FOGTEC. Passenger evacuation procedures remain unchanged and under the control of the Staff and Control Centre. Very quickly the water mist nozzles in the critical areas will be activated, covering the wagons with an innumerable amount of very small water droplets. The water mist will generate such a strong cooling effect that the fire brigade will be able to approach the fire source more rapidly. The concept further foresees a FOGTEC supplied video monitoring system.
Fire tests successfully carried out
The acceptance tests for the SAFE concept have just been carried out in a test tunnel in Spain on April 7 and 9, 2010. They are the largest fire tests that have ever been carried out with a fire suppression system. With various specialised firms and five scientific institutes involved in the testing, the conditions prevailing in the Eurotunnel in case of a fire were simulated on full scale under worst-case conditions. Under the leadership of FOGTEC, possible fire situations were thus reproduced under real conditions. Thousands of wooden pallets were burned as fire load. The energy output by the test fires amounted to 200MW, which corresponds to 40-50 fully burning cars. Temperatures up to 1,200 °C were measured. After the FOGTEC water mist system had been activated, temperatures in all-important areas were reduced to less than 50C° within 2 minutes.
In the event of a real fire in the Eurotunnel, the further propagation of a fire could thus be enormously reduced in a very short time. The environmental conditions and hence the survival conditions as a whole prevailing in the tunnel would be substantially improved.
Major step in tunnel safety
With this project, the water mist technology will for the first time be used in a railway tunnel, after various road runnels have already been furnished with the FOGTEC technology. For the planning of tunnels, this technology offers, in addition to a high increase in safety, considerable cost savings for the construction project as a whole.
Effects of water mist during fire fighting
The FOGTEC technology is based on the atomisation of water at a pressure of approx.100 bar. The system uses pure water and is absolutely eco-friendly. Pure water is taken via stainless steel pipes to specifically developed nozzles by which it is so finely divided into droplets that an artificial mist is formed. This results in an increase of the reaction surface of the water by approx. 100 times when compared with conventional systems. The great heat absorption capacity of the water is made considerably better use of in this system. So only between one and ten percent of the amount of water consumed by conventional techniques is required for the FOGTEC technology.