Crossrail’s western tunnels contractor, BAM/Ferrovial/Kier (BFK), is making use of the historic central London subway, closed since 1952, to build an 8m-deep, 5m-wide, grout shaft below the floor of the tunnel.
Grout shafts allow engineers to pump grout deep into the ground to firm it and protect nearby buildings from any potential ground movement when tunnel boring machines reach the area in 2013.
The tram tunnel underneath Kingsway once took passengers from Holborn to Waterloo Bridge, providing a link between the north and south London tram networks. For the past 60 years it has been all but abandoned, given over to several uses including local authority storage, and seldom opened to the public.
Crossrail area director west Keith Sibley said: “The Kingsway Tram Tunnel has played a fascinating and unique role in London’s transport history. Now it will play a vital part in helping prepare the ground for the city’s most ambitious transport project to date. As the tunnel is a Grade II listed structure, Crossrail will return the Camden section of the tram tunnel to its prior condition when the works are completed.”
London Transport Museum head of collections Martin Harrison-Putnam said: “The tram tunnel operated for less than 50 years and provided the only link between the north and south London tram networks. Opened in 1906, serving two subterranean stations at Holborn and Aldwych, the tunnel was enlarged in 1929 to accommodate double deck trams. The pioneering decision by London County Council to construct the country’s first tram tunnel was both innovative for its time and now of enduring historical importance.”
The shaft will be completed later this summer before the arrival of Phyllis and Ada, Crossrail’s western tunnel boring machines, in 2013.