The Connaught Tunnel and similar sites are being checked for unexploded bombs from World War Two before Crossrail works begin.
The 550m tunnel, which runs underneath the old Connaught Passage linking the Royal Albert and Victoria Docks and formerly used by the North London Line, suffered a hit in 1940. Experts want to make sure no other devices buried themselves in the soil before they start repairing and reinforcing walls. The middle section of the tunnel was narrowed in 1935 when the Passage was deepened; original 1878 brickwork was taken out and replaced with steel.
Crossrail contractors will dredge a section of the Passage next year and lay a reinforced concrete slab. This will allow the steel to be removed and a foam concrete (which sounds fun) added to the walls. And all this is just to prepare the tunnels for boring!
As well as checking for old bombs, archaeologists will have time to explore the Crossrail sites to see if they can find artefacts from London's buried past.
London Reconnections had a look round the Connaught Tunnel in 2010. Didn't spot any bombs, though.
Photo courtesy of London Reconnections.