"DW downunder" reply@newsgroup wrote in message
...


I'm not sure of the logic of platform doors restricting rollingstock to
dedicated Xrail only; in which case one should be planning enough loading
gauge for well-type DD cars once the eastern and western arms are cleared
through.

The expansion plan is to extend from 10 - 12 cars, the stations are 250m
long for that reason. I'd expect fixed formation trains (rather than 5+5 as
previously stated), with a Thameslink layout, ie with through gangways. But
the Crossrail tunnels are AFAICS UK gauge, with the track offset to one side
so that a continuous walkway can be provided. I expect double deckers won't
be possible, and even if gauging allowed, the dwell times would defeat 24
tph running..

Paul S

On Wed, 9 Sep 2009 11:46:07 +0100
"Paul Scott" wrote:
"DW downunder" reply@newsgroup wrote in message
...


I'm not sure of the logic of platform doors restricting rollingstock to
dedicated Xrail only; in which case one should be planning enough loading
gauge for well-type DD cars once the eastern and western arms are cleared
through.

The expansion plan is to extend from 10 - 12 cars, the stations are 250m
long for that reason. I'd expect fixed formation trains (rather than 5+5 as

250m long? That'll produce some interesting bunching of passengers down
one end. I doubt many people will spend 3 minutes walking down the length
of the platform.

previously stated), with a Thameslink layout, ie with through gangways. But
be possible, and even if gauging allowed, the dwell times would defeat 24
tph running..

If they had double deckers they wouldn't need 24tph. Even if they're not
planning UIC gauge trains, building the tunnels to UIC gauge would cost little
if anything extra. But this is britain, planning for unforseen future needs is
frowned upon as we all know.

B2003

wrote:

250m long? That'll produce some interesting bunching of passengers
down
one end. I doubt many people will spend 3 minutes walking down the
length
of the platform.

Most (all?) central stations are double ended.

On Wed, 9 Sep 2009 11:46:07 +0100, "Paul Scott"
wrote:

But the Crossrail tunnels are AFAICS UK gauge, with the track offset to one side
so that a continuous walkway can be provided. I expect double deckers won't
be possible,


That's correct. The tunnels are a nominal 6.20 metres in diameter
which precludes the use of double deck trains.


and even if gauging allowed, the dwell times would defeat 24
tph running..


You could argue that the increased capacity of double deck trains,
usually assumed to be 50% greater than a single deck train, would only
need 16 tph for the same throughput of passengers. If more than 16
tph could be operated, there would be a capacity increase over using
single deck trains.

However the capital cost of the project would be greatly increased,
with many overline structures between Shenfield/Woolwich and Reading
having to be rebuilt in addition to the much higher cost of the
Crossrail tunnels.

The French obviously thought building bigger tunnels was worthwhile,
with RER lines being built to take double deck trains. However, the
French did not need to spend huge amounts of money raising overline
structures on existing lines over which the RER trains run.

wrote in message ...
On Wed, 9 Sep 2009 11:46:07 +0100
"Paul Scott" wrote:
"DW downunder" reply@newsgroup wrote in message
...


I'm not sure of the logic of platform doors restricting rollingstock to
dedicated Xrail only; in which case one should be planning enough
loading
gauge for well-type DD cars once the eastern and western arms are
cleared
through.

The expansion plan is to extend from 10 - 12 cars, the stations are 250m
long for that reason. I'd expect fixed formation trains (rather than 5+5
as

250m long? That'll produce some interesting bunching of passengers down
one end. I doubt many people will spend 3 minutes walking down the length
of the platform.

Why should it? The central underground stations are double ended, (eg
Farringdon/Barbican, Moorgate/Liverpool St) with access to the platforms
via cross passages at about 1/4 and 3/4 along. I think they've thought of
that one...

Paul S

On Wed, 9 Sep 2009 10:55:13 +0000 (UTC), wrote:

If they had double deckers they wouldn't need 24tph. Even if they're not
planning UIC gauge trains, building the tunnels to UIC gauge would cost little
if anything extra.

Nonsense. The cost of building the Crossrail tunnels to accept double
deck trains would be considerably higher.

But this is britain, planning for unforseen future needs is
frowned upon as we all know.

But this is Boltar, who is an ignorant ****wit as we all know.

On Wed, 09 Sep 2009 12:48:32 +0100
Bruce wrote:
On Wed, 9 Sep 2009 10:55:13 +0000 (UTC), wrote:

If they had double deckers they wouldn't need 24tph. Even if they're not
planning UIC gauge trains, building the tunnels to UIC gauge would cost
little
if anything extra.

Nonsense. The cost of building the Crossrail tunnels to accept double
deck trains would be considerably higher.

Really, whys that then? Would the actual boring part of the TBM cost
substantially more if its diameter was increased by a metre? Would the extra
concrete cost raise the project costs much higher? Or are you just BSing
because you always want to appear to know best?

But this is britain, planning for unforseen future needs is
frowned upon as we all know.

But this is Boltar, who is an ignorant ****wit as we all know.

Ah , the irony.

B2003

On Wed, 9 Sep 2009 12:46:57 +0100
"Paul Scott" wrote:
250m long? That'll produce some interesting bunching of passengers down
one end. I doubt many people will spend 3 minutes walking down the length
of the platform.

Why should it? The central underground stations are double ended, (eg
Farringdon/Barbican, Moorgate/Liverpool St) with access to the platforms

Unless the entrances are spaced a reasonable distance apart then passengers
are going to have to walk those 250 metres at some point , whether its on
the platform or in a connecting tunnel.

B2003

On Wed, 9 Sep 2009 12:38:35 +0000 (UTC), wrote:

Really, whys that then? Would the actual boring part of the TBM cost
substantially more if its diameter was increased by a metre? Would the extra
concrete cost raise the project costs much higher? Or are you just BSing
because you always want to appear to know best?


This is an area where I have specialist knowledge, both as someone who
has worked on several tunnelling projects and someone who has been
responsible for tendering for tunnelling projects.

The cost of the tunnelling machine increases quite dramatically with
tunnel diameter; the cost of the excavation and of the tunnel lining
increases approximately with the square of the excavated diameter.
With the Landfill Tax, the disposal of the excavated material also
becomes a far greater problem as diameter increases.

On Wed, 09 Sep 2009 14:41:14 +0100
Bruce wrote:
On Wed, 9 Sep 2009 12:38:35 +0000 (UTC), wrote:

Really, whys that then? Would the actual boring part of the TBM cost
substantially more if its diameter was increased by a metre? Would the extra
concrete cost raise the project costs much higher? Or are you just BSing
because you always want to appear to know best?


This is an area where I have specialist knowledge, both as someone who
has worked on several tunnelling projects and someone who has been
responsible for tendering for tunnelling projects.

For the record, I don't believe you.

The cost of the tunnelling machine increases quite dramatically with
tunnel diameter; the cost of the excavation and of the tunnel lining
increases approximately with the square of the excavated diameter.

*sigh* I hate to break this pre-GCSE news to you, but the area of the
shaft of a cylinder increases *linearly* with increasing radius, not as the
square of it so the cost of the lining will not go up like that. The formula
you want incidentaly is 2*pi*r*h. So before you post anymore bull****
pretending your in-the-biz you might want to revisit your school books first.
As for the cost of the TBM - an extra metre diamater of the boring plate
would make no difference to the machinary required behind it.

B2003