Posted By Graham Bullough
Having been away for a fortnight's holiday since posting this thread, it's been interesting to read through the various responses, constructive, digressive or otherwise.

For those of you who didn't see it, the BBC TV news last night (Weds 1st Oct) showed footage of MOST of the recent fire-affected train being pulled out of the tunnel yesterday. All the lorries, including their tractor cabs, on the mesh sided wagons appeared to have been gutted by the fire spreading along the train. The newsreader said that some wagons were still to be recovered, so the tunnel in which the fire occurred is evidently still out of action some 3 weeks after the event. (The other tunnel (normally used for UK bound trains) is presumably being used for all trains - so the train-carrying capacity AND income of Eurotunnel are at best half of what they usually are until the France bound tunnel is repaired and restored to use.)

The news report concluded with a brief interview with an engineer who said that consideration now ought to be given to using ENCLOSED wagons complete with fire suppression systems!

Another thought: If a fire occurred in an enclosed wagon, wouldn't the build-up of smoke/reduction in oxygen inside it help, to some extent, to hinder combustion? This thought stems from the standard advice for anyone who suspects the presence of a fire inside a room in a building, i.e. don't open the door and thus allow an inrush of air which would enable a smouldering fire to suddenly flare up.

As some responders have commented, surely it is better for a train inside the tunnel with a known/suspected fire on board to continue moving so as to leave the tunnel and enable fire fighters to tackle the fire more promptly, more effectively and in greater safety than inside the confined space of the tunnel? Having enclosed wagons for lorries and other vehicles would surely contribute to this scenario. Also, being able to move a train with a contained fire on board to outside the tunnel would surely avoid or minimise the considerable and expensive damage caused by fire to the tunnel lining, etc. As regards the possibility of explosion, enclosed wagons could surely incorporate explosion relief panels.

Posted By Graham Bullough
Colin - Thanks for your information and comment about the crossovers between the two tunnel bores. If they are used to maximise the capacity of the tunnel until the section where the fire occurred is restored for use, I guess that the tunnel controllers, no doubt working with computer-controlled signalling and automatic doors at the crossovers, will be relieved when they can revert to the normal situation of each bore being used for one way traffic.

As for the comment in my original posting about the benefit of having a rail tunnel rather than a road tunnel, I would expand it by suggesting that there is far more to go wrong with vehicles than trains in a tunnel especially an unusually long one like the Channel Tunnel: Vehicles are prone to punctures and other breakdowns. Think of the ramifications for other tunnel users plus vehicle recovery and emergency service people arising from inevitable vehicle breakdowns, collisions and accidents. The fuel on each vehicle, especially so in the case of petrol, poses a risk if it escapes during an accident. If drivers and passengers in vehicles being driven through the tunnel were banned from smoking as a precaution in case of fuel spillage, no doubt some people would be tempted to ignore it. Also, vehicle drivers are prone to various distractions or even dozing off, especially through the monotony of driving through a 51 km/32 miles long tunnel.

In various respects, including the containment and extinguishing of fires - the main thrust of this thread, try thinking of the tunnel as an extraordinarily long confined space.