wrote in message

On 06/08/2011 08:41, Recliner wrote:
"Michael wrote in message
. uk
In . co.uk
Michael wrote:

There is an interesting article about heat (as experienced by
passengers) in the Tube in this week's New Scientist.


Michael Bell

The problem with on-train refrigeration is that it dumps the heat
into the tunnel, which get back into the train which....

A work-round discussed in this article is for on-train refrigeration
to make ice while the train is on the surface and allow it to melt
while in the tunnel. But not all routes have surface sections.

A truly radical idea might be to pipe on board at the terminus
liquid air (no need to separate it into oxygen and nitrogen) and
evaporate it in the tunnel. Disposal of the waste is not a problem!

Apart from the last idea, I think these are quite old, superseded
proposals. As I understand it now, the current active proposals a
1. Improve ventilation of deep Tube stations, to extract heat from
the system (already happening)
2. Fit airconditioning to new lightweight articulated Tube stocks
which have regen brakes and will produce less heat from their motors
(hoped for in the proposed replacement for 1972, 73 and 92 stocks).


About what articulated Tube stock do you speak?

There's an LU proposal to resurrect some of the ideas from the abortive
Space train, which was derailed by Gordon Brown's PPP scheme which has
thankfully now collapsed. I understand that the usual manufacturers are
being asked for preliminary outline proposals, and the Siemens version
has appeared in the rail magazines. The articulated trains would have
open gangways (giving more passenger space), a smaller number of bogies
and light monocoque bodies to save weight. This would reduce power
consumption, allowing air-conditioning to be fitted.

It would be another large order, like the S stock, to replace the
existing trains on several lines (at least four), so it's worth some R&D
to come up with something creative (unlike the strictly conventional
PPP-originated 2009 and S stocks). Like the S stock and the 1938-1962
Tube stocks, this would run on several lines.