Eurotunnel installs safe stations to rapidly detect and extinguish flames

Eurotunnel engineers have installed the first of a new four part anti fire system that has been shown to quench fires in minutes.

The system incorporates a series of “safe stations” equipped with novel water-mist pumps.

“There are fibre optic heat detectors that localise exactly where the seat of the fire is and within seconds the water-mist system is set off to target it,” said Euro tunnel spokesman John Keefe.

The specially designed nozzles achieve a dispersal rate of around 200m cubed of water per hour, all in micro droplet form. Tests have shown the system to reduce the temperature of the fire from around 900C to 250C in less than three minutes.

“There is so much water in the air that it stifles the access of any oxygen from the rest of the tunnel,” added Keefe.

Part of the strength of the system lies in the infrastructure. There are four emergency safe stations comprising sidings of 870m (to accommodate a slowing train) equipped with the heat sensors and water mist pumps. In the event of a fire, trains will be able to drive into one of the emergency sidings, which are never more than 10 minutes away, at a speed of 100km per hour.

Keefe said: “in testing, we found that there is a perfect speed that prevents the fire from getting too much oxygenation and growing and spreading backwards along the train, and also prevents it from growing in situ – the balance between a wind that is fanning t and a wind that is putting it out.

“At 100KM per hour we can drive it in a contained manner to the safe station, then before it starts to expand the water mist is released and puts it out very quickly,” he added.

It is expected that all the four safe stations will be completed and in place by the end of the year, at a cost of £17m. 

Sourced from "the Engineer" magazine 

BY ANDREW CZYZEWSKI