Thread: EU lending for Crossrail
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Old September 9th 09, 03:06 PM posted to uk.railway,uk.transport.london,misc.transport.urban-transit
Basil Jet Basil Jet is offline
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First recorded activity at LondonBanter: Jun 2009
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Default EU lending for Crossrail
wrote:
On Wed, 09 Sep 2009 14:41:14 +0100
Bruce wrote:

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.

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.


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