Calais Frethun ‘Bunker’ Platforms

[tynesider]

Hi all

Something I’ve noticed and always wondered what they are / what purpose they serve.

In the tunnel / Frethun / Calais Ville triangle, there seems to be at least two platforms with direct access into large manmade bunkeresque mounds of earth, with access into the ‘bunkers’ running the length of the platforms at various points.

They’re visible from the Eurostar on the High Speed Line, and curve towards the tunnel at their West end / Calais Ville towards the east. At a guess, I’d assume they can accommodate full length Eurostar set, and they seem to be too far away from the Eurotunnel terminal to serve that’s purpose. There doesn’t appear to be any signage on the platforms, so I’m guessing they're for some sort of emergency use, but that still doesn’t explain what the ‘bunkers’ are for.

Anybody have any idea?

 

[30907]

Hi all

Something I’ve noticed and always wondered what they are / what purpose they serve.

In the tunnel / Frethun / Calais Ville triangle, there seems to be at least two platforms with direct access into large manmade bunkeresque mounds of earth, with access into the ‘bunkers’ running the length of the platforms at various points.

They’re visible from the Eurostar on the High Speed Line, and curve towards the tunnel at their West end / Calais Ville towards the east. At a guess, I’d assume they can accommodate full length Eurostar set, and they seem to be too far away from the Eurotunnel terminal to serve that’s purpose. There doesn’t appear to be any signage on the platforms, so I’m guessing they're for some sort of emergency use, but that still doesn’t explain what the ‘bunkers’ are for.

Anybody have any idea?

Sorry, can't locate these on satellite view - which tracks are they on?

 

[BahrainLad]

Dropped pin
Near 62185 Fréthun, France
https://goo.gl/maps/9a4eA4jmNEAnAmzWA

Seems to be one line with these “bunker” entrances parallel. Odd.

 

[jamesontheroad]

It is identified on this user-generated map on Wikipedia as the “voie d’urgence” - emergency track.

 

[nag67]

Labelled as the Emergency Siding in Quail.

 

[30907]

Dropped pin
Near 62185 Fréthun, France
https://goo.gl/maps/9a4eA4jmNEAnAmzWA

Seems to be one line with these “bunker” entrances parallel. Odd.

Looks to me (just from satellite view) as if it is designed to evacuate passengers quickly through the mound onto the pathway on its far side, a place of safety from whatever has happened to the train. An onboard fire or explosion?

 

[edwin_m]

I seem to remember the original idea was that a train on fire in the tunnel would carry on if possible and be diverted into one of these tracks, where it could be dealt with without risking the fire spreading to other trains and vehicles in the terminal itself. In all the major fires the train has in fact been unable to continue, so possibly they wouldn't have been provided if they'd known then what they know now. The Quail also shows a UK emergency track, south of the vehicle loading tracks.

 

[duesselmartin]

Into a closed space with passengers?

 

[30907]

I seem to remember the original idea was that a train on fire in the tunnel would carry on if possible and be diverted into one of these tracks, where it could be dealt with without risking the fire spreading to other trains and vehicles in the terminal itself. In all the major fires the train has in fact been unable to continue, so possibly they wouldn't have been provided if they'd known then what they know now. The Quail also shows a UK emergency track, south of the vehicle loading tracks.

Interestingly, the track at Cheriton has 2 walled sections, about 80m long and about 300m apart, and no obvious escape to a place of safety, so seems to be a slightly different concept.
The space at Frethun is much less enclosed.

 

[edwin_m]

The ones most obviously at risk of fire (and the only ones to have had any significant fires) are the HGV shuttles, where the accompanying drivers travel in a club car at the front so the rest of the train can burn away without causing immediate harm to people. Perhaps the emergency tracks were or still are only intended for these trains? As an aside I can't imagine how they expected to manage a fire on one of these without stopping, when the through draught in the partly-open wagons made it virtually certain that a lorry on fire would ignite the one behind it. It would be instructive to read the reports on the various Tunnel fires, which are freely available on the link below, as they probably describe the emergency management arrangements in some detail. I'll maybe re-read them if I get some time over the holidays.

http://www.railwaysarchive.co.uk/ev...opment=all&published=no&acctype=all&submit=Go
[list of accidents on Eurotunnel - nothing to quote on that page]

 

[edwin_m]

The ones most obviously at risk of fire (and the only ones to have had any significant fires) are the HGV shuttles, where the accompanying drivers travel in a club car at the front so the rest of the train can burn away without causing immediate harm to people. Perhaps the emergency tracks were or still are only intended for these trains? As an aside I can't imagine how they expected to manage a fire on one of these without stopping, when the through draught in the partly-open wagons made it virtually certain that a lorry on fire would ignite the one behind it. It would be instructive to read the reports on the various Tunnel fires, which are freely available on the link below, as they probably describe the emergency management arrangements in some detail. I'll maybe re-read them if I get some time over the holidays.

http://www.railwaysarchive.co.uk/ev...opment=all&published=no&acctype=all&submit=Go
[list of accidents on Eurotunnel - nothing to quote on that page]

Answering my own question, I've skimmed these reports for any details of procedures for handling a fire on a train and of what actually happened. In each case the incident was a fire originating in a vehicle on board an HGV shuttle (albeit in one case due to the radio aerial touching the catenary).

• From the 1996 fire report it appears that the original plan was for any train where fire was detected to continue if possible to the emergency siding at its exit. If this wasn't possible for an HGV shuttle the loco would haul the amenity coach with the lorry drivers out on its own. The train was unable to do this due to damage from the fire and once it stopped catenary damage made it impossible to re-start. Most of those on board were hospitalized and normal working had apparently not resumed by the time the report is issued, but the report itself is undated. I recall this incident causing many months worth of disruption.
  
• The 2006 fire report doesn't mention the emergency sidings as far as I can tell from a quick search. It says that the policy was now to bring a [HGV] shuttle to a stop when a fire was detected and evacuate via the service tunnel. This appears to have been achieved successfully with no injuries and normal service was resumed the next day.
  
• The 2008 report states that on detection a fire the train should continue to an emergency siding if possible, except HGV shuttles that have not yet passed the last ventilation shaft prior to their exit, which should be stopped and evacuated. This was done but various things went wrong along the way, although no serious injuries resulted. The tunnel suffered "considerable damage" but date of re-opening doesn't appear to be stated.
  
• The 2015 report describes how the procedure now take account of the two "SAFE stations" provided in each tunnel, equipped with water mist systems. Freight shuttles with a detected fire should stop in one of these if possible, unless the amenity coach is at the rear in which case they should stop immediately. If the braking point for the second SAFE station has been passed the shuttle should continue to the emergency siding at the exit. However the controller has to make this decision and during the decision process the train passes a braking point. A trip of the overhead power supply related to the fire then forced it to stop (this could probably have been reset, allowing it to continue), after which evacuation went smoothly. There was some damage to the tunnel but full service was restored six days later.
  
• The 2018 report is into an accident at Dollands Moor freight yard so isn't relevant here.

These are the only accident reports relating to Eurotunnel, so it would appear that the emergency track has never been used to manage a significant incident.

 

[Ianno87]

I believe in the 1996 fire the reason the train had to stop was that the fire caused the driver to have an indication that the stabilisation jacks were lowering (used when the train is stopped to balance the wagons when lorries are being on/off-loaded) - thus there would have been a derailment risk to a moving train. I'm not sure they had actually lowered - the fire damage gave a false indication.

ISTR the 96 fire took about 7 or 8 months to repair, the 08 fire about 2 or 3.

 

[edwin_m]

I believe in the 1996 fire the reason the train had to stop was that the fire caused the driver to have an indication that the stabilisation jacks were lowering (used when the train is stopped to balance the wagons when lorries are being on/off-loaded) - thus there would have been a derailment risk to a moving train. I'm not sure they had actually lowered - the fire damage gave a false indication.

ISTR the 96 fire took about 7 or 8 months to repair, the 08 fire about 2 or 3.

The report states that the failure was in the "props control circuit" which implies that the circuit caused the props to be lowered when not commanded. However it may be that detection function was part of that control circuit, in which case the props could have been indicated to be in an unsafe position when actually safe. This is a case where the traditional railway design practice of failsafe and stop whenever there is a problem may not be appropriate. Perhaps aviation practice could have been used, where redundancy for critical functions* allows the flight to continue even if one component fails. Shutting everything down in the event of a fault isn't a sensible policy when half way across the Pacific and it probably isn't when half way across the Channel either.

*unless you're a 737 MAX...