Engineers working on HS2 have retrieved TBM Caroline from below ground at the Green Park Wy site in Greenford, west London.
The 9.48m diameter cutterhead, front and middle shield, weighing 850 tonnes, were lifted using a large gantry crane on Sunday, May 25. TBM Caroline finished the 8km drive from West Ruislip in April, arriving in an underground reception chamber. It excavated more than 1.2 million tonnes of earth and installed 4,217 tunnel rings.
Named by a local school after the astronomer Caroline Herschel, TBM Caroline was used to construct part of the Northolt Tunnel – a 13.5km tunnel being built by four TBMs that will take HS2 trains from Old Oak Common Station to the outskirts of the capital. TBM Sushila, the first machine to arrive at Green Park Way, was removed in March.
TBM Emily, launched in February last year, and TBM Anne launched in April last year, are building the eastern section of the tunnel from HS2’s Victoria Road Crossover Box just outside the Old Oak Common station site.
HS2’s London tunnels contractor, Skanska Costain Strabag joint venture (SCS), is responsible for building the route through London. In total, this involves 20.7km of twin-bore tunnels, including the Northolt Tunnel and the Euston Tunnel, which will eventually take the railway from Old Oak Common station into HS2’s central London terminus at Euston.
