Power cables TBM breaks through at Willesden in London

23 January 2013

J Murphy & Sons has completed breaking through on the Willesden to Taylors Lane Deep Cable Tunnel Project in north London for UK Power Networks, it was announced last week. The 2.59km tunnel where the 56t TBM arrived will house four new 132,000-volt cable circuits, linking between two substations upgrading electrical supplies in the area.

The completed 1271m of tunnel saw the TBM excavating through London clay at a depth of some 28m deep prior to arriving into a 7.5m reception shaft that had been previously constructed within the National Grid Sub Station, Acton Lane. The tunnel passed underneath eleven Network Rail lines with the drive averaging 16m for every 10 hour shift. Bernice navigated several challenging 70m radius bends along the route, requiring sections of the TBM belts to be shortened to manoeuvre around the tunnel curves.

"This is a major milestone for our tunnelling team," Darren Ramsay, Murphy Tunnelling, Civils & Power managing director, said. "The tunnel has been delivered safely, on time and budget in close collaboration with UK Power Networks."