C:Amie - 2005-07-08 1:42 PM
As you say, the tube system can be very confined in places, as someone who has been known to commute mainline / underground combinations I can attest to that. They can gain access to the cars from either direct of the tunnel, and they will probably uncouple the head and tail cars (car three was hit on the kings cross one for example) and get directly to the blast scene that way - again once it has been cleared forensically.
Assuming that the tunnel doesn't collapse first...
The tunnel has already partially collapsed, which probably isn't supprising for iron segments from the 1910's. For reference purposes, I thought I would include a description of the trains used on the Piccadilly line
WARNING!!! LENGTHY AND TECHNICAL DESCRIPTION AHEAD!
description of the trains
The trains are of 1973 Tube Stock
(entered service in 1975 instead. It was aticipiated that they would enter service in 1973 for the Heathrow extension
). They have aluminum bodies and conventiaul DC traction gear, one majour thing they had that wasn't in common with other stocks is that instead of having seperate camshafts for braking and motoring, they both were combined into one larger unit.
(Camshafts use a series of contacts to increase the power given to the motor, also to reduce the power to the motors. This is because the motors cannot accept the line voltage at startup
).
They were recently refurbished at Bombardier at Doncaster, previously was owned by British Rail Engineering Ltd, who was the orignal contractor for refurbishment work, this is because after the Kings Cross file of 1987, the trains were found to have unsuitable interiors, the wooden flooring and the seats would burn vigiously and give off toxic fumes. During the refurbishment
(after several prototypes
), the seating in all cars was totally altered, the bay seating was done away with, leaving longitude seating through the carriages, increasing the usable space, especially during PIXC
(Passangers In eXcess Capacity - Strategic Rail Authority term
) or "crush load conditions". New flooring was fitted throughout the car, which emitted low emissions, but still burned. This was more controllable however, the seats were re-placed and given a different pattern to them, this is suppose to be fireproof, or to the manufactures. Majour technical upgrades were taken.
The couplings would cause a majour problem, most tube stock run as 3 car trains, except the 1992 stock and the sub-surface stock
(A, C, D stocks
), the usual formation is in this order;
[li]Driving Motor, fitted with a driving cab and motors on all axles of the bogies (otherwise known as the DM)
[li]Trailer, but is often fitted with compressors and no motors (T)
[li]Uncoupling Non-Driving Motor with motors and traction equipment. These also have a small shunting cabnet for shunting purposes (UNDM or "Undun"
The stocks prior to the 73 stocks are formed into trains with a DM-T-UNDM+UNDM-T-DM. On the Bakerloo 1972 stock, one half is the same, but the other half is a DM-T-T-DM. 1967 stock on the Victoria line has a DM-T-T-DM+DM-T-T-DM and the 1992 Central line stock is VERY complicated! Because a service train is 8 cars long, each car was made up into 4 units, 2 units with cabs and 2 units with no cabs, the cars are descibed as follows
(letter signifies the car designitioj
)[list=A]
[li]Driving motor car with traction equipment, shoes and motors
[li]Uncoupling driving motor with no shoes, or traction equipment, but does have compressors and a shunting cabnet
[li]As B but with shoes and traction equipment, no compressor
[li]As B but with de-icing equipment
I won't go into formations, because they are far too complicated. Basically, every unit has a B or D car, it doesn't matter what car is on the other end.
Between the cars of every unit, each car is coupled by a semi-perminate or perminate bar coupling, this is because the individual cars are not meant to be spit anywhere outside the depot. Any attempt to rescue the 1973 stock is going to become very difficault because of this, you have to physically break the coupling. I believe the couplings are made of either thick steel or iron, most likely the latter. The other 3 cars can escape safely, because they can be driven backwards. All you have to do is disengauge the "Wedgelock" coupling, break the pneumatic connections and the electrical contacts and you are fit to drive backwards
(providing you are authorized by the controller and the police to move the other 3 cars
). So, I do think the resuce operation is going to be more difficault than the bus, although with the bus, you could get a load of officers to conduct a finger tip search, if possible
(in theroy
).
Sorry about that, I thought the descirption would be useful for most who are interested, as many need to know the saftey features, how it can and cannot be resuced and how difficault it would be on LU. I am a train enthusiast............. I withdraw what I was going to add to that.
Sometimes, it just doesn't seem fair. 
