"Tom Barry" wrote

And without Boris trumpeting them as meeting a manifesto commitment, to
boot. 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.

Peter

"Peter Masson" wrote in message

"Tom Barry" wrote

And without Boris trumpeting them as meeting a manifesto commitment,
to boot. 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.

That's why the plan is to cool the stations, not the trains, but of
course there's less to see with that approach.

On 23 July, 16:17, "Recliner" wrote:
"Peter Masson" wrote in message



"Tom Barry" wrote

And without Boris trumpeting them as meeting a manifesto commitment,
to boot. *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.

That's why the plan is to cool the stations, not the trains, but of
course there's less to see with that approach.

And the regenerative braking on the new 2009 stock will also mean less
heat released into the stations and tunnels in the first place.

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

"Tom Anderson" wrote in message
rth.li
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.

I think it makes a lot more sense to just take more heat out of the
stations and maybe the tunnels as well. That means more surface
ventilation fans running (which is think is already happening) and some
sort of additional cooling, such as the plan to use heat exchangers with
the cold ground water being pumped out. That way, the passengers in the
stations benefit as well, and you don't need to complicate the already
cramped trains any more than they are already.

Peter Masson wrote:


"Tom Barry" wrote

And without Boris trumpeting them as meeting a manifesto commitment,
to boot. 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.

Peter

AIUI, however, the new rolling stock is going to have some sort of new
venting system that will make journeys cooler.

Right?

On Sun, 26 Jul 2009, wrote:

Peter Masson wrote:

"Tom Barry" wrote

And without Boris trumpeting them as meeting a manifesto commitment, to
boot. 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.

AIUI, however, the new rolling stock is going to have some sort of new
venting system that will make journeys cooler.

Right?

Right. it's basically just much better ventilation. Someone posted a study
by some physicists a while back that suggested it would make the insides
of the cars a few degrees cooler. Not an awful lot, but significant.

tom

--
She got destiny, she got supremacy, she got everything ever from A to Z.

On 23 July, 09:48, John B wrote:
So the 09s entered passenger service before the 378s? Didn't see that
one coming...

Yes... but worth noting they're only testing one 2009ts train on an
occasional basis for now, whereas the 378s have already completed
testing and are in series production.

When they finally sort whatever the current hold up is there will
immediately be several 378s running on a full time basis, and
hopefully they'll be quickly followed by the rest of the fleet. The
same won't be true of the 2009ts for another 6 months.

U