On Wed, 9 Apr 2008, John B wrote:

Other interesting highlights:

* the trains must weigh less than 32 tonnes per coach

Is there an external driver for that requirement, or does it just come
from the Good Ideas Club at the ministry?

tom

--
Yesterday's research projects are today's utilities and tomorrow's
historical footnotes. -- Roy Smith

On Wed, 9 Apr 2008, Tom Anderson wrote:

On Wed, 9 Apr 2008, John B wrote:

Other interesting highlights:

* the trains must weigh less than 32 tonnes per coach

Is there an external driver for that requirement, or does it just come
from the Good Ideas Club at the ministry?

Oh, here we go:



4.1 Train mass (weight) is a critical parameter for whole system, whole
life cost because it affects both track maintenance and train energy
consumption. The Department and Network Rail both understand the virtuous
circle that can be created between track quality and train mass and
Network Rail is committed to improve track quality through its new
standards for maintenance.

4.2 The Department and Network Rail wish to work with Bidders to establish
a set of weight targets which can be set in the ITT. The Department is
aiming at a target of 256 tonnes (tare) per 162m train or 384 tonnes
(tare) per 243m train which is believed to be achievable.



A 162 metre train made of 20 metre cars is an 8 car train, and an 8 car
train which weights 256 tonnes has 32 tonne cars. If the supplier goes for
26 metre cars, six per train, they could weigh 42 tonnes. I have no idea
if there are reasons 26 metre cars can't be used; i believe the Southern
network has curves which preclude their use, but don't know if Thameslink
will use those.

tom

--
Yesterday's research projects are today's utilities and tomorrow's
historical footnotes. -- Roy Smith

On Apr 9, 10:46 pm, Tom Anderson wrote:
4.2 The Department and Network Rail wish to work with Bidders to establish
a set of weight targets which can be set in the ITT. The Department is
aiming at a target of 256 tonnes (tare) per 162m train or 384 tonnes
(tare) per 243m train which is believed to be achievable.

A 162 metre train made of 20 metre cars is an 8 car train, and an 8 car
train which weights 256 tonnes has 32 tonne cars. If the supplier goes for
26 metre cars, six per train, they could weigh 42 tonnes. I have no idea
if there are reasons 26 metre cars can't be used; i believe the Southern
network has curves which preclude their use, but don't know if Thameslink
will use those.

The central Thameslink route has trouble with stock longer than 20m, I
think. There's another bit in the document where DfT suggests that
it'd be happy to think about longer trains as long as the manufacturer
thinks about ways of making them fit [presumably along the lines of
'we'll add GBP15m of extra value if you do GBP10m of widening'].

To achieve the two required total lengths, 20m trains would need to be
4-car units and 26m trains 3-car units.

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

On Apr 10, 8:44*am, John B wrote:


if there are reasons 26 metre cars can't be used;



I would suggest there would be door access issues with stock longer
than 20 m.

On 20 m cars like 317/319/321 and 450/377/375 and 376 et al door
spacing is approx 1/3 and 2/3 car. A 26 m car would be more like 1/4
and 3/4 door spacing - which would lead to longer dwell times - any
more to place doors further towards the middle of a 26 m car would
have to larger a throwover at curved platforms - of which there are
too many stations to resolve.

If you take a look a 444s at Waterloo where the country end of a 10car
is on the curve its easy to see how much a 23 m car throws over. 444s
have end-ish doors so its no big deal - but imagine even 1/3 + 2/3
spacing on one of those cars leads to a big gap.

I'd have thought going the other way - to *shorter* but articlulated
cars might be better.

--
Nick

Tom Anderson wrote:

On Wed, 9 Apr 2008, John B wrote:

Other interesting highlights:

* the trains must weigh less than 32 tonnes per coach

Is there an external driver for that requirement

No, the driver can be on board.

--
http://gallery120232.fotopic.net/p13309739.html
(43 090 at London Kings Cross, 29 Nov 1980)

In message , at 21:59:07
on Wed, 9 Apr 2008, Chris Tolley remarked:
* the trains must weigh less than 32 tonnes per coach

Is there an external driver for that requirement

No, the driver can be on board.

The DfT needs to get everyone on board for this project to be a success.
--
Roland Perry

On Apr 10, 7:14 am, Roland Perry wrote:
Is there an external driver for that requirement

No, the driver can be on board.

The DfT needs to get everyone on board for this project to be a success.

....and in less than 45 seconds, too!

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

On Wed, 9 Apr 2008, Chris Tolley wrote:

Tom Anderson wrote:

On Wed, 9 Apr 2008, John B wrote:

Other interesting highlights:

* the trains must weigh less than 32 tonnes per coach

Is there an external driver for that requirement

No, the driver can be on board.

That rather depends on how much he weighs, i would think.

tom

--
Freedom, Beauty, Truth, and Love!

On Apr 9, 12:44 pm, John B wrote:

* the trains must weigh less than 32 tonnes per coach

Yeah, like that's going to happen. I've just flicked through
TheRailwayCentre.com and it looks like only 315s, 508s and some ex-LUL
trains (all inner-sub units) currently meet that criterion. As for
outer-sub units, 317s and 321s would be approximately 10 tonnes too
heavy in 4-car formation (and the 319s up to another 5 on top) while
the 4-car SR Electrostars are almost 50 tonnes above the limit! And
don't even get me started on the Desiros and Javelins (well OK I don't
have the figures to hand but they are very heavy indeed).

On Apr 9, 11:48*am, wrote:
http://tinyurl.com/5asy9b
http://tinyurl.com/5deoog

I love the fact that at the end of a highly detailed, demanding
technical specification for a train that is meant to be suitable for
metro-style ATO as well as Kings Lynn to Eastbourne runs, there is the
following:

"Maintenance downtimes must be significantly reduced from the current
increasing trend that has arisen due to unnecessary sophistication".