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

Increased dwell times would mean longer journeys at /any/ tph and and
lower tph would mean longer wait times too.

Any designs for double decker /platforms/ to go with double decker
trains ?

"Plenty of room on top" (VBG).

--
Mike D

On Wed, 9 Sep 2009 15:20:50 +0000 (UTC), 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.


You are truly, profoundly ignorant, because if there is one thing that
London Clay demonstrably is not, it is "self-supporting".

A lot of good science has gone into the manufacture of sophisticated
unbolted concrete linings that not only support the far from
"self-supporting" London Clay, but deform in a controlled way to offer
greater support where needed.

These concrete linings require great precision in manufacture, with
tolerances that are much tighter than those usually achieved in
precast concrete manufacture, being more comparable to the manufacture
of precision cast and ductile iron linings.

Of course, as a time-served and fully qualified ****wit you couldn't
possibly have known any of this, which is why it would have been a
sensible idea for you to STFU in the first place. But you are Boltar,
and Ignorant always beats poor old Sensible, and Knowledgeable and
Expert never get a look in.

"Michael R N Dolbear" wrote in message
news:01ca31a0$aa1aec60$LocalHost@default...
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. But this is britain, planning for unforseen future
needs is
frowned upon as we all know.

Increased dwell times would mean longer journeys at /any/ tph and and
lower tph would mean longer wait times too.

Any designs for double decker /platforms/ to go with double decker
trains ?

"Plenty of room on top" (VBG).

--
Mike D



Sorry to have caused some "heat", guys.

I said 'twas a pity they aren't to make provision for this as a stage 3, for
future capacity growth. I know Stage 1 will be fitted for 200m single deck,
triple-door-openings per-side trains at Day 1, and they say Stage 2 will be
fitted for 240m trains. The platform tunnels will be built at Stage 1 to, I
suspect 250m total length - but not fully fitted. The trains will have to be
dedicated to XRail at first, though later builds for Overground and Inner
London TOC services might also be built to the same dimesions and door
positions and thus be potentially Xrail compatible.

The increase in size needed to achieve well-type DD in OHLE lines in UK is
actually fairly modest - the main thing being room for "hips" and
"shoulders", so a non-circular shape would be best. I believe X-Rail are
mooting non-circular tunnels. The normal height of 3965mm is almost
sufficient, perhaps 4000mm to 4050mm would give scope for further increases
in median tallness of the British railway commuter population. It's the
shoulders and hips where the designs would be cramped for kinematic envelope
in current loading gauges. One wouldn't need any of the UIC gauges as such,
just sufficient to accommodate a 2895/2900-ish mm width from about 200mm
above rail to about 3300mm above rail.

As regards tunnelling costs, when I put the case in Perth, Western Australia
for using 3rd rail through the underground and Narrows Bridge sections - the
first to allow smaller diameter tunnels and the 2nd for aesthetic reasons -
I was informed by a Mr Mann, the project's chief engineer, that the cost
differential between bored 4.6m tunnels and bored 6m tunnels was negligible.
This is in an area of saturated dune sands, clays and silts with little
sedimetary rock and no hard rock - so tunnel lining performance parameters
would be critical. IMHO, I was served bureaucratic claptrap, but if he is
correct then XRail could future proof without blowing their business case.

I was also informed that the cost of dual voltage stock was an order of
magnitude more expensive. The implication being that whatever might be saved
in tunnelling cost would be blown by higher rolling stock cost - which is a
periodically recurring cost rather than a one-off. Bombardier won the
contract to supply the traction equipment for them. As these trains have
been built and delivered this decade, how does that assertion match with
UTL/UKR contributors' knowledge of the comparative cost of AC-only, AC/DC
and DC-only versions of the same base model UK EMU in the same period?

Again, I put this idea into play as a future-proofing concept, such that
when the "overground" sections are cleared to the let's call it UK "X2"
loading gauge, then the capability can be exploited to buffer growth in
numbers (and median size) of pax.

Cheers all

DW downunder

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

On Thu, 10 Sep 2009 00:17:02 +0100
Bruce wrote:
On Wed, 9 Sep 2009 14:20:42 +0000 (UTC), 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.


But as someone with [no] experience of tunnel lining design, manufacture
and installation I can tell you with authority that the larger the
diameter of the tunnel, the thicker the lining needs to be.

There , fixed it for you.

B2003

On Thu, 10 Sep 2009 16:11:59 +0800
"DW downunder" reply@newsgroup wrote:
I was informed by a Mr Mann, the project's chief engineer, that the cost
differential between bored 4.6m tunnels and bored 6m tunnels was negligible.
This is in an area of saturated dune sands, clays and silts with little
sedimetary rock and no hard rock - so tunnel lining performance parameters

Cue Bruce on how you must also be a profoundly ignorant ****wit as this
clearly is impossible. Obviously an extra 1.4m would raise the price so high
no one in their right mind could state the cost difference was negligable?

Isn't that right Mr Fantasy Tunnel Designer Bruce? (Though I suspect the
only "tunnel" he's ever been involved in building is making one out of
a rolled up newspaper)

B2003

On 2009-09-09 15:20:42 +0100, said:

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

But the volume of material being excavated /does/ increase as the
square of the diameter. If the tunnel diameter is increased from 6.5
metres to 7.5 metres, a 15 per cent increase, the volume of spoil
increases by 33 per cent. (All numbers rounded).

This is not insignificant. The machinery driving the 'boring plate'
would have to be scaled up to cope and the extra spoil disposed of.
--
Robert

Robert wrote:

But the volume of material being excavated /does/ increase as the
square of the diameter. If the tunnel diameter is increased from 6.5
metres to 7.5 metres, a 15 per cent increase, the volume of spoil
increases by 33 per cent. (All numbers rounded).

It's actually more, because, as mentioned elsewhere, the tunnel lining gets
thicker as well.

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.
--
http://gallery120232.fotopic.net/p9683684.html
(53103 (Class 116) at Lichfield City, 13 Jun 1985)

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