London Banter - View Single Post

Bruce[_2_] · May 27th 10, 11:44 AM posted to uk.transport.london

On Thu, 27 May 2010 02:09:07 +0100, Basil Jet
wrote:

On 26/05/2010 15:04, Paul Terry wrote:
In message , d writes

Tunnels arn't dug with
picks and shovels any more - a TBM won't care if it has to dig the whole
tunnel itself or theres a small tunnel already there , it will take
more or
less the same time. The only difference will be in the amount of spoil
needing to be carried away.

Which reminds me that there were several proposals to use the Post
Office Railway to remove spoil from the central area. I haven't heard
anything more of the suggestion, though.

Wouldn't it be easier to remove the spoil by the Crossrail tunnels they
had just dug?

Not necessarily. In most tunnelling projects you have conflicting
movements of excavated spoil coming out and lining segments going in,
with workers going in and out. If the spoil comes out via a separate
route, it reduces conflicts and might improve progress.