![]() |
EU lending for Crossrail
|
EU lending for Crossrail
|
Was: ( EU lending for Crossrail) NOW: XRail tunnel diameter
"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 |
EU lending for Crossrail
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 |
EU lending for Crossrail
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 |
Was: ( EU lending for Crossrail) NOW: XRail tunnel diameter
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 |
EU lending for Crossrail
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. |
EU lending for Crossrail
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) |
EU lending for Crossrail
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 |
All times are GMT. The time now is 07:49 AM. |
Powered by vBulletin®
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2006 LondonBanter.co.uk