David Walters wrote:
That's the old plan. A new one was announced today: http://www.crossrail.co.uk/news/pres...nnaught-tunnel
Crossrail originally planned to strengthen the central section
of the tunnel by removing the existing steel linings and back
filling the entire section with concrete foam. These tunnels
would then have been enlarged by boring through the concrete to
create tunnels that are large enough for Crossrail trains to pass.
Crossrail will now place cofferdams in the Connaught Passage
between the Victoria and Royal Albert Docks, pump out the water
and create a dry construction site allowing workers to dig down
to the tunnel to undertake the enlargement work through a .cut
and cover. approach.
Oh, well. That's blown the budget. ;-)