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