Neil Williams wrote:
...which would instead cause similar crowds in stations or just
outside.

It wouldn't work, which is probably why it hasn't been done.

Why can't we air condition the stations at least? These can be just as
unbearable, and it can't be TOO difficult to do. Expensive, yes, but a
decent system could clean and filter the air too.

I know the deep level stations have the problem of heat extraction, but
if you can sort out the stations then it must help overall passenger
comfort. Else have part of a train that collects the extracted heat,
which is then vented at a station?

Jonathan

Jonathan Morris wrote:

Neil Williams wrote:
...which would instead cause similar crowds in stations or just
outside.

It wouldn't work, which is probably why it hasn't been done.

Why can't we air condition the stations at least? These can be just as
unbearable, and it can't be TOO difficult to do. Expensive, yes, but a
decent system could clean and filter the air too.

I know the deep level stations have the problem of heat extraction, but
if you can sort out the stations then it must help overall passenger
comfort. Else have part of a train that collects the extracted heat,
which is then vented at a station?

Jonathan

"Might" be feasible on a small station, but a place like Oxford Circus
has a total of 4 2/3 miles* of passageway (inc non public). Now look at
the air con plants at your place of work and consider where you'd put
one big enough to make a difference round OXO C
, or any other decent sized central London station. And as for Bank ...

The trains have a similar problem - any aircon plant big enough to deal
with 100 people per carriage is going to be too big to fit under the
floor or seats (scale up a four person car plant ...). And you have to
carry the heat out of the tunnel, not dump it in so you would need one
hell of a heat sink - with the same space constraint problem, as well
as a reliable system of dumping the heat when in the open and not in
the tunnel - and thats without the problem of the Victoria Line where
the trains only surface when in the depot...

The other issue is cost / benefit. After all do you really want to pay
for all this expensive engineering when the number of days the tube is
really unbearable is in finger counting territory in a typical year ?

On 11 Jun 2006 00:44:42 -0700, "Mark W"
wrote:

The other issue is cost / benefit. After all do you really want to pay
for all this expensive engineering when the number of days the tube is
really unbearable is in finger counting territory in a typical year ?

Do you travel in the rush hour?

--
James Farrar
. @gmail.com

In article . com, Mark
W writes

Jonathan Morris wrote:

Neil Williams wrote:
...which would instead cause similar crowds in stations or just
outside.

It wouldn't work, which is probably why it hasn't been done.

Why can't we air condition the stations at least? These can be just as
unbearable, and it can't be TOO difficult to do. Expensive, yes, but a
decent system could clean and filter the air too.

I know the deep level stations have the problem of heat extraction, but
if you can sort out the stations then it must help overall passenger
comfort. Else have part of a train that collects the extracted heat,
which is then vented at a station?

Jonathan

"Might" be feasible on a small station, but a place like Oxford Circus
has a total of 4 2/3 miles* of passageway (inc non public). Now look at
the air con plants at your place of work and consider where you'd put
one big enough to make a difference round OXO C
, or any other decent sized central London station. And as for Bank ...

snip
But if we can cool the stations even a bit then when the trains stop
some of the internal heat can be exhausted.
I agree that air-con on the trains is virtually a non-starter - there is
nowhere for the heat to go and not enough space for the heat exchanger.
However, if we cool the stations then there is a chance that the tunnels
and trains will also be a bit cooler.
Obviously any ground water already pumped away should be used as a heat
sink, but surely we could also use water to transfer heat from the
platforms to the surface (heat exchanger both ends?

--
John Alexander,

Remove NOSPAM if replying by e-mail