wrote:
On Wed, 09 Sep 2009 19:19:24 +0100
Arthur Figgis wrote:
deckers, because of cost and not being able to send the trains somewhere
else and/or sell them second-hand afterwards.

So they wouldn't be able to sell 2nd hand UIC gauge 25Khz trains? Have they
not heard of this place called "Europe"?

Not unless Johnny Foreigner adopted our platform heights and things, or
we rebuilt to match their standards, which would be a big job unless
Crossrail is completely separated from the rest of the network.

--
Arthur Figgis Surrey, UK

wrote:
On Wed, 09 Sep 2009 19:19:24 +0100
Arthur Figgis wrote:
deckers, because of cost and not being able to send the trains
somewhere else and/or sell them second-hand afterwards.

So they wouldn't be able to sell 2nd hand UIC gauge 25Khz trains?
Have they not heard of this place called "Europe"?

There'd certainly be no capacity problems running at that frequency...

Paul S

On 9 Sep, 12:46, Bruce wrote:
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.

Don't forget the loss of capacity due to increased dwell times loading
a DD train...

On 10 Sep, 10:38, wrote:
On Wed, 09 Sep 2009 19:19:24 +0100

Arthur Figgis wrote:
deckers, because of cost and not being able to send the trains somewhere
else and/or sell them second-hand afterwards.

So they wouldn't be able to sell 2nd hand UIC gauge 25Khz trains? Have they
not heard of this place called "Europe"?

B2003

25KHz? thats one helluva service frequency

On Thu, 10 Sep 2009 17:33:10 +0100, Tom Barry
wrote:

wrote:
On Wed, 9 Sep 2009 16:06:03 +0100
"Basil Jet" wrote:
wrote:
*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.
It's a good job you didn't write those schoolbooks, otherwise they'd say
that a one-inch diameter pipe and a five-metre diameter pipe need walls
which are the same thickness.

Remind me how a 10% increase in diameter size required to fit UIC gauge trains
in the tunnel in mostly self supporting london clay is going to cost so much
more because of huge extra lining thickness apparently required.

B2003


I hate to leap to the defence of either of you, but I suspect Bruce's
comment about the costs of *excavation* is more relevant than the costs
of lining. The area of lining is proportionate to the radius of the
bore, but the weight of excavated material is proportionate to the
square of the radius, as are transport and disposal costs. Add in the
strengthening required for the greater load borne by the lining for a
bit more £ on top, this obviously includes transport costs for whatever
they're using for the lining.

What's missing in this back-and-forth ranting is an estimation of the
proportion of Crossrail costs that are directly related to the
tunnelling rather than the station fit-out, land acquisition,
electrification, trains etc. If it's only 5% of the costs, then going
large won't break that much of the bank. If it's 50%, then you're
talking in £billions.

One other benefit of double-deck trains, by the way, is shorter train
lengths for the same capacity (which saves money on station lengths, but
not in the capacity of escalators etc.). That's at the expense of dwell
times, though, unless you do something really clever like having
double-height platforms with doors on the upper deck too (I like the
sound of that, actually).

Tom

Would there be sufficient space to build larger tunnels, or will they
be so deep as to avoid other tunnels, foundations etc. ?

In message
Chris Tolley (ukonline really) wrote:

Robert wrote:

The machinery driving the 'boring plate'
would have to be scaled up to cope

One suspects that since tunnels are already routinely bored to the
larger dimensions on the mainland, such kit is readily available,
whereas the factory in Liliput making the UK-sized kit went out of
business ages ago through lack of orders.

I got the impression that TBMs were custom made for each job.

--
Graeme Wall

This address not read, substitute trains for rail
Transport Miscellany at www.greywall.demon.co.uk/rail

rail wrote:

In message
Chris Tolley (ukonline really) wrote:

Robert wrote:

The machinery driving the 'boring plate'
would have to be scaled up to cope

One suspects that since tunnels are already routinely bored to the
larger dimensions on the mainland, such kit is readily available,
whereas the factory in Liliput making the UK-sized kit went out of
business ages ago through lack of orders.

I got the impression that TBMs were custom made for each job.

I'm sure they are. But I do imagine that whoever makes them keeps the
blueprints.

--
http://gallery120232.fotopic.net/p9632845.html
(33 043 at Exeter St Davids, 1985)

GazK wrote:

Don't forget the loss of capacity due to increased dwell times loading
a DD train...

Dwell time issue only become significant if the train a significant
percentage of the passenger carrying capacity of the DD train
boards/alights at every stop on the route.

In most systems that doesn't happen, with large boarding/alighting
flows only occurring at a relatively small number of stops along the
route.

Bill Bolton
Sydney, Australia

In message
Chris Tolley (ukonline really) wrote:

rail wrote:

In message
Chris Tolley (ukonline really) wrote:

Robert wrote:

The machinery driving the 'boring plate'
would have to be scaled up to cope

One suspects that since tunnels are already routinely bored to the
larger dimensions on the mainland, such kit is readily available,
whereas the factory in Liliput making the UK-sized kit went out of
business ages ago through lack of orders.

I got the impression that TBMs were custom made for each job.

I'm sure they are. But I do imagine that whoever makes them keeps the
blueprints.


Since tunnels come in various different sizes all over the world I suspect
the manufacturers have more than one set of blueprints in the drawer.

--
Graeme Wall

This address not read, substitute trains for rail
Transport Miscellany at www.greywall.demon.co.uk/rail

Bill Bolton wrote on 11 September 2009
09:20:55 ...
GazK wrote:

Don't forget the loss of capacity due to increased dwell times loading
a DD train...

Dwell time issue only become significant if the train a significant
percentage of the passenger carrying capacity of the DD train
boards/alights at every stop on the route.

In most systems that doesn't happen, with large boarding/alighting
flows only occurring at a relatively small number of stops along the
route.

Bill Bolton
Sydney, Australia

This isn't "most systems". It's London, and all 6 of the central area
stations on Crossrail (the ones where 24tph are currently planned)
*will* have heavy boarding/alighting flows.

--
Richard J.
(to email me, swap 'uk' and 'yon' in address)