On Thu, 23 Jul 2009 11:19:39 +0100, "Recliner"
wrote:

"Peter Masson" wrote in message

"Recliner" wrote

Surely there were large numbers of 1959 and 1962 stock trains in
service by then? Admittedly, their design was pretty similar to the
1938s, so they may not have seen much newer.
They did, and the 1959 stock were the first 'silver' trains - but
they did not run on the lines used by the previous poster at the time.

Weren't there silver R stock trains before then?

1949 IIRC - apparently they dismantled one after they were withdrawn
and the body was reckoned to still have a few more years left in it.

1506 wrote:
On Jul 22, 1:08 pm, Stephen Furley wrote:
On 22/7/09 16:00, in article
, "Paul

Corfield" wrote:
An internal (LU) notice has stated that the first passenger service
journey of the new Victoria Line 09 stock took place last night just
before midnight from Seven Sisters down to Brixton. More passenger
service trips will build up over the coming months using trains 01 and
02.
I thought people might be interested to know.
--
Paul Corfield
via Google
The Victoria Line stock was the first new stock that I remember being
introduced. It seemed incredibly modern at the time compared to the CO and
R stocks which I was used to on the Circle and District when going to the
Science Museum, the first journey up into central London which I made on my
own, and the 38 stock which I occasionally used on the Bakerloo or Northern;
these were the only Underground lines which I'd used at that time. It's odd
to think that it's reached the end of its life, and due to be replaced.

That is my memory of the London Subway also. In the Early 1960s the
tubes were, by and large served by 1938, and earlier stock. The sub-
surface lines were CO and R stock served. The Victoria Line trains
and the A stock on the Met. seemed SO modern.


God, your making me feel my age, I can remember the 'Q' stock on the
District, the 'T' & 'F' stock on the Met & the pre-1938 on the Central &
Pic.
I can also remember the loco hauled stock on the Met.

--

Tony Dragon

On Thu, 23 Jul 2009, Recliner wrote:

"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.

But you don't cool the interiors of the trains as much as you would with
on-board AC.

I don't doubt that a station cooling approach gets a better
degrees-per-pound ratio, averaged over the whole underground space at
least, and so is a more sensible option. But i do wonder if there aren't
workable ways to get the insides of the trains cooler than is achievable
that way.

tom

--
When I see a man on a bicycle I have hope for the human race. --
H. G. Wells

Tom Anderson wrote:
--
When I see a man on a bicycle I have hope for the human race. --
H. G. Wells

H.G - meet Doug.

"Tom Anderson" wrote in message
th.li
On Thu, 23 Jul 2009, Recliner wrote:

"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.

But you don't cool the interiors of the trains as much as you would
with on-board AC.

I don't doubt that a station cooling approach gets a better
degrees-per-pound ratio, averaged over the whole underground space at
least, and so is a more sensible option. But i do wonder if there
aren't workable ways to get the insides of the trains cooler than is
achievable that way.

I'd say that cooling the stations is a pre-requsite to air-conditioning
the trains, given how hot the Victoria Line tunnels already are. It's
less of an issue with the other Tube lines, as the trains pump a lot of
fresh air in already at the portals.

Tim Fenton wrote:

"1506" wrote in message
...

That is my memory of the London Subway also.

That's going a long way back. Kingsway closed along with the rest of the
tram network in 1952.

There seems to be a Subway on every street, these days...

--
Arthur Figgis Surrey, UK

On Jul 23, 4:57*pm, Andy wrote:

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


Ummm thats not strictly true. Overall you might be generating less
heat directly from braking, true, but the type of train, with AC
motors, will itself create more heat to be released, including
indirectly from braking.

Go back to the NR southern third rail zone power upgrade for Mk.1
stock replacement. What was that all about. All the new trains coming
in had AC motors, replacing DC motors under the Mk.1s. The big issue
was heating effect.

AC motor characterisitics are such that it draws a higher constant
current - this means the heating effect in lineside traction equipment
is much increased - because heat dissipated is I^2*R [I-squared-R].
When the trains are regenerating, the heating effect in lineside eqpt
is still I^2*R, it still is still being heated, it does not cool
because it is reversed, and it does not cool because t gets no respite
(like it does when a friction brake train brakes). A non regen braked
train using friction brakes disspates the heat transformed from
mechanical energy at the brake shoes/pads - wheel rim/disc interface.
A regen braked train convert mechanical energy to electrical, which
while contributing a useful energy saving does nonetheless heats
lineside gear in doing so.

1967 stock Crompton/Brush LT115 DC traction motors are 53 kW cont.
rating.
2009 stock Bombardier Mitrac AC traction motors are 75 kW cont.
rating.

1967 stock 8-car trains are MTTMMTTM - 16 motors per train = 16 x 53
kW = 848 kW per train
2009 stock 8-car train are MTMMMMTM - 24 motors per train = 24 x 75
kW = 1800 kW per train

All those motrs and traction packs get hot.

A 2009 stock train draws over twice the traction load of 1967 stock,
and thats before you look at DC v. AC, and before you look at
auxiliary loads. All this air-con draws a load that was not there with
1967. Thats never put back into regen braking.

Further, the service frequency will be increased, and there are more
trains in service at any one time. True they will all regenerate, but
there are more of them to accelerate in the first place, and
accelerating at a higher rate.

It all adds up - I bet one would not be far wrong to say current draw
on the whole line with full TPH with 2009 stock may well be 3 times
that of 1967 stock at the same voltage. Offset this by increasing
from 630 V to 750 V which is a 30% current drop, so overall load
doubled.

All that heat has to go somehwere. And Peter is quite right, there is
nowhere to dump the air-con load.

NR southern zone has trackside power distrbution cables everywhere, LU
does not, so at east not heating tunels that way.

There is a substantial uplift in heating effect from the new trains.
Unless my sums are seriously flawed, there'd have to be some seriously
hefty cooling gear to cool stations. Gear that itself draws power ...
maybe more than the entire train regenerated power is taken up by air-
con ?


--
Nick

"D7666" wrote

There is a substantial uplift in heating effect from the new trains.
Unless my sums are seriously flawed, there'd have to be some seriously
hefty cooling gear to cool stations. Gear that itself draws power ...
maybe more than the entire train regenerated power is taken up by air-
con ?

Add to that the congestion relief works at Victoria and the more frequent
service, there'll be more passengers pumping kilowatts into the system.

Perhaps the Victoria Line needs to be extended into the open air, at least
so the piston effect of trains can add ventilation into the tunnels, and
ideally so that the next generation (49 stock) can have aircon that takes
heat out of the system and dumps it in the open air. Take over Chingford
from National Rail? Quadruple Northumberland Park to Cheshunt, with a
extended Victoria Line running the local service?

Peter

On Jul 24, 6:19*pm, D7666 wrote:
On Jul 23, 4:57*pm, Andy wrote:

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

Ummm thats not strictly true. Overall you might be generating less
heat directly from braking, true, but the type of train, with AC
motors, will itself create more heat to be released, including
indirectly from braking.

Ok, so how much more heat would be generated if the trains were not
regenerating?


Go back to the NR southern third rail zone power upgrade for Mk.1
stock replacement. What was that all about. All the new trains coming
in had AC motors, replacing DC motors under the Mk.1s. The big issue
was heating effect.


And how much of the extra power requirement came from the trains being
heavier.

AC motor characterisitics are such that it draws a higher constant
current - this means the heating effect in lineside traction equipment
is much increased - because heat dissipated is I^2*R [I-squared-R].
When the trains are regenerating, the heating effect in lineside eqpt
is still I^2*R, it still is still being heated, it does not cool
because it is reversed, and it does not cool because t gets no respite
(like it does when a friction brake train brakes). A non regen braked
train using friction brakes disspates the heat transformed from
mechanical energy at the brake shoes/pads - wheel rim/disc interface.
A regen braked train convert mechanical energy to electrical, which
while contributing a useful energy saving does nonetheless heats
lineside gear in doing so.

But much of the regenerated energy should be going into powering other
trains, sure you need hefty lineside kit in case everything all brakes
at the same time, but the Victoria line should be ideal for reusing
the energy. Also isn't the peak current draw less with AC than DC. The
AC motors will be warming up fairly constantly during the whole of the
acceleration (and deccelaration) phases and so their heat production
will be spread out. The old DC motors will warm up much more quickly
at the start as that is the point of peak current draw and, of course,
this is will be in the stations.


1967 stock Crompton/Brush LT115 DC traction motors are 53 kW cont.
rating.
2009 stock Bombardier Mitrac AC traction motors are 75 kW cont.
rating.

1967 stock 8-car trains are MTTMMTTM - 16 motors per train = 16 x 53
kW = 848 kW per train
2009 stock 8-car train are MTMMMMTM - 24 motors per train = 24 x 75
kW = 1800 kW per train

All those motrs and traction packs get hot.


Piers Connor (in his series The Underground Electric Train in
Underground News, June 2007) say the following:

"In order to make use of the additional throughput capability of the
new signalling, the
2009 Stock has a higher performance than the current stock. The
existing 1967
Tube Stock draws about 2,700 amps maximum, while the 2009 Tube Stock
will draw
3,500 and is capable of drawing up to 4,500 amps."

This looks like well under double the peak current draw.


A 2009 stock train draws over twice the traction load of 1967 stock,
and thats before you look at DC v. AC, and before you look at
auxiliary loads. All this air-con draws a load that was not there with
1967. Thats never put back into regen braking.

Further, the service frequency will be increased, and there are more
trains in service at any one time. True they will all regenerate, but
there are more of them to accelerate in the first place, and
accelerating at a higher rate.

It all adds up - I bet one would not be far wrong to say current draw
on the whole line with full TPH with 2009 stock may well be 3 times
that of 1967 stock at the same voltage. Offset this by *increasing
from 630 V to 750 V which is a 30% current drop, so overall load
doubled.

All that heat has to go somehwere. And Peter is quite right, there is
nowhere to dump the air-con load.


Lineside equipment will be MUCH easier to cool, as it is in fixed
locations which should already be ventilated.

NR southern zone has trackside power distrbution cables everywhere, LU
does not, so at east not heating tunels that way.

There is a substantial uplift in heating effect from the new trains.
Unless my sums are seriously flawed, there'd have to be some seriously
hefty cooling gear to cool stations. Gear that itself draws power ...
maybe more than the entire train regenerated power is taken up by air-
con ?


Just to be clear, I wasn't arguing for air conditioning to be fitted,
but I still think you are mis-estimating the effect of regeneration on
the total energy consumption and heating for the new trains. The whole
point of regeneration is to reuse the energy which used to be 'wasted'
in resistor banks on the trains (with the original rheostatic train
brakes). My understanding is that little of the recovered energy goes
back to the lineside equipment, if the current rails are not
receptive, then the spare energy goes to resistors, like in older
stock. The extra big lineside equipment is purely because more current
is needed in the first place.

Andy wrote:

Just to be clear, I wasn't arguing for air conditioning to be fitted,
but I still think you are mis-estimating the effect of regeneration on
the total energy consumption and heating for the new trains. The whole
point of regeneration is to reuse the energy which used to be 'wasted'
in resistor banks on the trains (with the original rheostatic train
brakes). My understanding is that little of the recovered energy goes
back to the lineside equipment, if the current rails are not
receptive, then the spare energy goes to resistors, like in older
stock. The extra big lineside equipment is purely because more current
is needed in the first place.

What happened to the test of trackside rotating cylinders designed to store
the energy from regenerative braking?