A hi-tech heat detection system which uses water mist to contain fire, reducing temperatures from 900°C to 250°C in less than three minutes, has been demonstrated by Channel Tunnel operator Eurotunnel.
In the event of a blaze in the tunnel, trains will be able to drive into an emergency siding or one of four new 870m-long Safe stations.
Micro-droplets will then be released, absorbing oxygen in the air and so smothering the fire without needing to be aimed directly at the source of the blaze.
Trials showed that the water mist can contain the equivalent of a fire involving 40 cars on a Shuttle train.
“The installation of the Safe stations will revolutionise the management of a fire in the tunnel,” said a Euro-Tunnel spokesman.
“In effect, the Channel Tunnel will be divided into three sections, each approximately 17km long, which will mean that this infrastructure, already the safest in the world because of the unique service tunnel, will attain a level of safety far superior to any comparable structure.”
“In effect, the significant reduction in temperature near the seat of the fire also prevents the fire from developing and improves visibility,” he added.
“The water mist, which carries no risk to people, delivers rapid control of the fire and reduces damage to the infrastructure of the tunnel.”
Officials also said the Safe stations, which are due to be installed by the end of the year at a cost of £17M, will make it easier for passengers to evacuate when a Eurostar train breaks down without a risk of fire.
The four stations are to be installed between the two crossovers - galleries that allow trains to cross from one tunnel to the other.
The demonstration comes after a fire broke out in the tunnel on a Folkestone to Calais train about seven miles from the French end in September 2008, leaving thousands of holidaymakers stranded and resulting in closure of the link between Britain and France.
Construction of a 120m prototype Safe station was completed in the tunnel early last year.