|Link to Crossrail web site|
"There will be a total of 42km of bored tunnels located below the busy streets of London. The tunnels will weave their way between existing underground lines, sewers, utility tunnels and building foundations from station to station, at depths of up to 40m.
"In the second quarter of 2012, the first two tunnel boring machines (TBMs) will start out on their journey from Royal Oak, towards the west of Farringdon station.
"This will be followed later in the year by the launch of two further tunnel boring machines in Docklands, that will head under central London towards the east of Farringdon. Further shorter tunnel drives will take place in the Royal Docks and east London.
"Teams of dedicated construction workers will be working 24 hours a day to complete the tunnels for Europe's largest civil engineering project ,with thousands of others employed to upgrade the existing rail network, and build major new stations along the central section of the route.
"Tunnel portals will be constructed at Royal Oak, Pudding Mill Lane, North Woolwich, Victoria Dock, and Plumstead."