Battersea cable tunnel: powering regeneration in central London, UK.

A new primary electrical substation is being provided to support regeneration of the Battersea Power Station and surrounding Nine Elms area in central London. Due for completion in 2019, it required tunnelling 330 m under rail tracks to connect to an existing 132 kV cable tunnel. As described in this paper, the new spur tunnel was constructed using an open-face tunnelling shield beneath rail viaducts and a Victorian sewer. Through careful sequencing and close monitoring, a volume loss of just 1% was achieved during construction of the complex junction chamber connection with the existing wedge-block tunnel.