On Apr 21, 6:11*pm, Boltar wrote:
On 21 Apr, 13:55, Andy wrote:

(per car). Having every axle motored generally allows better
acceleration, if all other things are equal. It will be interesting to
see how the Northern stock performs, once the trains are used to their
full potential.

Why arn't they using it already, what are they waiting for? The A
stock was doing 60 mph back in the 1960s with no ATO in sight.

B2003

Basically because the signalling can't cope. Thing's like stopping
distances and overlaps are set up for the 1959 stock. A 1995 stock
train approaching a signal more quickly than a 1959 stock train leads
to potential problems with the overlap distances; as does accelerating
more quickly from a platform. The original plan was for a replacement
of the trains to be followed immediately by replacement of the
signalling. However, the money for the signalling and track upgrade
was cut, leading to new trains which had to be detuned to run safely
on old signalling setup.

What I don't know is if the 1996 on the Jubilee line is also detuned
compared to maximum performance, awaiting introduction of new
signalling, or whether the history of most of the line being part of
the Metropolitan means that the signalling is better setup for
'mainline' performance.

On Apr 21, 4:16*pm, Mizter T wrote:
On 21 Apr, 13:55, Andy wrote:



On Apr 21, 12:46 pm, Mizter T wrote:

On 21 Apr, 11:39, "Paul Scott" wrote:

"thoss" wrote:

At 03:06:46 on Mon, 21 Apr 2008 Boltar opined:-

Change the traction package on a unit, and put it back in service.
Don't see why that would require closing the line. * It might not
be possible to couple a DC unit and an AC unit in a single train,
but they can certainly share the same track and power rails.

If they do it lets hope they don't reduce the performance of the
central line trains to the slug like performance of the northern line
ones. The central trains are the only ones on the tube that have
anything approaching the decent acceleration that you'd expect on
a modern metro.

Is that because of the trains or because on the tube sections
acceleration is aided by gravity?

It is because the Central line has full automatic train operation (ATO),
which for normal day to day use drives the trains nearer the limits than
manual driving can. *There is no reason why a change from DC to AC
traction would make performance worse, in fact it ought to improve
AFAICT.

Indeed - it's all about the ATO.

There is also the fact that all axles are motored on the Central
line's 1992 stock, whilst the Northern line's 1995 stock has two
trailer cars per 6 car unit. This means that the '92 stock is lighter
(per car). Having every axle motored generally allows better
acceleration, if all other things are equal. It will be interesting to
see how the Northern stock performs, once the trains are used to their
full potential.

Though, speaking from a position of total ignorance here, might the
motors on the Northern line trains be more powerful, thus less are
needed?

Indeed they are, but the problem is more putting the power to the
track. The size of the wheels on tube stock means that best
performance was gained by using small, less powerful (DC) motors under
the cars in the 1992 stock and powering every axle. By the time that
the 1995/6 stock came along, the AC motors became suited to the task
and these are more powerful for their size than the DC ones. I think
that when the 1992 stock was being designed, there was no motor
powerful enough to both fit under the cars and give the desired output
per train, without having every axle powered.

There is also the consideration of adhesion. Having more axles powered
spreads the 'push' out and gives less chance of wheelslip etc., when
it is wet or icey.

In message
,
Boltar writes
Why arn't they using it already, what are they waiting for? The A
stock was doing 60 mph back in the 1960s with no ATO in sight.
So was 62 stock on the Central line, but it was not authorised for use
in tunnel sections.
--
Clive

On 21 Apr, 18:17, John B wrote:
On 21 Apr, 18:10, Roland Perry wrote:

That's GBP1-1.5m per train, or GBP150-200k per carriage. Doesn't
sounds a million miles out...

For a couple of electric motors!!!!

About 10% of the cost of a new carriage to replace the whole drive
system? Sounds pretty reasonable to me...


Are Underground carriages really about GBP 1.5m-2m? I thought recent-
ish DC electric surface stock (e.g. the 450s on SWT) came in at about
GBP 1m per carriage, and for that you get motors, brakes and
crashworthiness suitable for 100MPH running, aircon, PIS and toilets!

Steve Adams

On Apr 22, 9:57 pm, Steve wrote:
Are Underground carriages really about GBP 1.5m-2m? I thought recent-
ish DC electric surface stock (e.g. the 450s on SWT) came in at about
GBP 1m per carriage, and for that you get motors, brakes and
crashworthiness suitable for 100MPH running, aircon, PIS and toilets!

[x-posted to uk.railway]

Most recent "more or less for cash" order on the Tube is EUR149m with
Alstom for the 85 new cars on the Jubilee, so about GBP1.4m per car at
current rates (no idea what proportion of components are built in
Europe vs UK vs US$-linked-developing-countries, so actually GBP1-1.4m
depending on the ratio).

I thought we were running closer to GBP2m for mainline stock - one of
the railway magazines (I'd guess may have been Roger Ford, since it's
the kind of thing he'd do) had an interesting table a couple of years
ago on the subject, IIRC showing HEx stock at the most expensive at
around GBP3m per vehicle, but I can't find it online.

TfL's North London Railway upgrade seems to be running at GBP1.4m per
vehicle:
http://www.tfl.gov.uk/corporate/medi...hive/3534.aspx

--
John Band
john at johnband dot org
www.johnband.org

On Apr 22, 8:09 pm, Clive wrote:
In message
,
Boltar writesWhy arn't they using it already, what are they waiting for? The A
stock was doing 60 mph back in the 1960s with no ATO in sight.

So was 62 stock on the Central line, but it was not authorised for use
in tunnel sections.

I'm not surprised. Could you imagine the piston effect that would
have? People waiting on platforms would be blown down the tunnel

B2003

On 23 Apr, 00:46, John B wrote:
On Apr 22, 9:57 pm, Steve wrote:

Are Underground carriages really about GBP 1.5m-2m? I thought recent-
ish DC electric surface stock (e.g. the 450s on SWT) came in at about
GBP 1m per carriage, and for that you get motors, brakes and
crashworthiness suitable for 100MPH running, aircon, PIS and toilets!

[x-posted to uk.railway]

Most recent "more or less for cash" order on the Tube is EUR149m with
Alstom for the 85 new cars on the Jubilee, so about GBP1.4m per car at
current rates (no idea what proportion of components are built in
Europe vs UK vs US$-linked-developing-countries, so actually GBP1-1.4m
depending on the ratio).

I thought we were running closer to GBP2m for mainline stock - one of
the railway magazines (I'd guess may have been Roger Ford, since it's
the kind of thing he'd do) had an interesting table a couple of years
ago on the subject, IIRC showing HEx stock at the most expensive at
around GBP3m per vehicle, but I can't find it online.

TfL's North London Railway upgrade seems to be running at GBP1.4m per
vehicle:http://www.tfl.gov.uk/corporate/medi...hive/3534.aspx

--
John Band
john at johnband dot orgwww.johnband.org

Some analysis from 2003, less the chart referred to in the text, at:
http://www.alycidon.com/ALYCIDON%20R...004%202003.htm

On 23 Apr, 09:02, Boltar wrote:

On Apr 22, 8:09 pm, Clive wrote:

In message
,
Boltar writes
Why arn't they using it already, what are they waiting for? The A
stock was doing 60 mph back in the 1960s with no ATO in sight.

So was 62 stock on the Central line, but it was not authorised for use
in tunnel sections.

I'm not surprised. Could you imagine the piston effect that would
have? People waiting on platforms would be blown down the tunnel


How about we just ditch the trains and install massive fans to create
public wind tunnel transportation - people could just jump in and out
of the airflow. It'd be an exhilarating ride too, though those with a
sensitive disposition about their hair (Mrs Prescott, Natasha
Kaplinsky etc) will likely opt to stay in their Jags or taxi's on the
surface. The tunnels might need a bit of a clean to remove all the
dust first, and some padded lining to cover the tunnel walls might not
be a bad idea either.

The alternative would be to turn the tunnels into massive water
flumes, so we'd have something akin to a water park under central
London. Now that does sound like a good idea!

On Wed, 23 Apr 2008, Mizter T wrote:

On 23 Apr, 09:02, Boltar wrote:

On Apr 22, 8:09 pm, Clive wrote:

In message
,
Boltar writes
Why arn't they using it already, what are they waiting for? The A
stock was doing 60 mph back in the 1960s with no ATO in sight.

So was 62 stock on the Central line, but it was not authorised for use
in tunnel sections.

I'm not surprised. Could you imagine the piston effect that would have?
People waiting on platforms would be blown down the tunnel

How about we just ditch the trains and install massive fans to create
public wind tunnel transportation - people could just jump in and out
of the airflow.

This has been semi-seriously proposed in relation to cycle lanes - since
the main limit on bike speed is air drag, if you move the air at 10 mph in
the direction of travel (involving putting the cycle lane in a tube), you
give everyone a 10 mph speed boost.

The alternative would be to turn the tunnels into massive water flumes,
so we'd have something akin to a water park under central London. Now
that does sound like a good idea!

Ahem.

http://groups.google.co.uk/group/uk....27e4f928db8b5a

And that wasn't even the first time i suggested it, ISTR.

tom

--
YOU CANT TAKE AWAY HATGUYS HAT. THEN HE IS JUST GUY -- The_Toad

On 23 Apr, 12:23, Tom Anderson wrote:

On Wed, 23 Apr 2008, Mizter T wrote:

On 23 Apr, 09:02, Boltar wrote:

(snip)

I'm not surprised. Could you imagine the piston effect that would have?
People waiting on platforms would be blown down the tunnel

How about we just ditch the trains and install massive fans to create
public wind tunnel transportation - people could just jump in and out
of the airflow.

This has been semi-seriously proposed in relation to cycle lanes - since
the main limit on bike speed is air drag, if you move the air at 10 mph in
the direction of travel (involving putting the cycle lane in a tube), you
give everyone a 10 mph speed boost.

Ha, I haven't come across that idea before! It has to be said that
when the air is moving at 10mph against the direction of travel, or
indeed perpendicular to the direction of travel, cycling can be damn
hard work. Still, it's all good for you - a friend used that very same
philosophy when he came by a large number of knobbly off-road tyres
and used them for his on-road cycle commute - "it's just going to make
me harder"!

Incidentally, whilst we're on the topic of cycle innovations, have you
come across this:
http://news.bbc.co.uk/newsbeat/hi/te...00/7340963.stm


The alternative would be to turn the tunnels into massive water flumes,
so we'd have something akin to a water park under central London. Now
that does sound like a good idea!

Ahem.

http://groups.google.co.uk/group/uk....owse_thread/th...

And that wasn't even the first time i suggested it, ISTR.


Even as I was typing I was thinking 'this is a very Tom Anderson thing
to say, I bet he's said it already'!

Though your suggestion above is for canals - I was thinking more along
the lines of passengers being issued with rubber rings and the water
in the tunnel being propelled along to give a rapids-like effect,
perhaps with a pool at each station so one could get out.

Man it's a shame there aren't any water parks in London or the
surrounds these days!