The role of the Kingsway Tram Tunnel in the construction of the Elizabeth line is now complete and it has been returned to the London Borough of Camden.
Since 2012, Crossrail Ltd has been in control of the section owned by Camden, because of the tram tunnel’s location directly above the Elizabeth line tunnels that go through Holborn.
Owned by Westminster City Council as well as the London Borough of Camden, possession of the Kingsway Tram Tunnel allowed those engineers working on the Crossrail project to pump grout – a cement-like substance – into the ground so that tiny ground movements could be corrected which occurred because of the construction of a 30-metre deep temporary access shaft nearby.
This correction of any movement was possible because an eight-metre deep, five-metre wide shaft was excavated within Kingsway Tram Tunnel so engineers were able to pump in the grout, which also proved useful when the tunnel boring machines passed.
A 40-tonne dry cement silo and two bore holes were then used to pump water, air, electricity and cement into the railway six storeys below ground.
Now more than 90% complete, handing back the tram tunnel is another milestone in the whole project, which will see the first use of the Elizabeth line in December 2018.
The next step is removing visible evidence of its use to support the Elizabeth line’s construction, with temporary protection fixtures and fittings set to be removed, and the whole site repaired.
Iron rails will be put back into place as the site is returned to the London Borough of Camden.
Bill Tucker is Crossrail’s Delivery Director. He believes the tram tunnel’s place in the history of London’s transport network makes it fitting that it has contributed so significantly to this fantastic new infrastructure project.
He said: “The Kingsway Tram Tunnel holds a special place in London’s transport heritage. Built to connect one of London’s earliest transport networks, it is fitting that the tunnel helped us build the capital’s newest railway.”