On Thu, 23 Jul 2009, Peter Masson wrote:

"Tom Barry" wrote

If they'd only had aircon...

Among the problems with aircon on the tube lines is - where do you dump
the heat? Presumably on, say, the Central or Piccadilly lines it would
be possible to devise a system whereby the heat was retained on the
train until it got to the open air, and then dumped, but Victoria Line
trains stay underground all the time they are in service. No use cooling
the trains if you just heat the tunnels even more.

You'd have to install a fake open air. By which i mean some point on the
line where trains could stop and offload their heat - some apparatus they
sit inside which blows a gale of super-cooled damp air (or even water)
into their heat exchangers, and sucks the warmed exhaust out again. You
wouldn't want to do it in passenger service, but if you could build ten
minutes into the schedule at one end, it could be done during turn-around.
Admittedly, this would involve changing the Victoria operating principle
quite a bit, but at least it's technically feasible. Ish.

tom

--
Oh, and sometimes in order to survive you have to drink the irradiated
water from an old toilet. -- Jon, on Fallout