National Grid is undertaking a seven-year project to rewire London via deep underground tunnels.
Record-breaking tunnelling contract
Skanska is working in a joint venture with Costain (CSJV) on the project, due for completion in 2018. The work includes the completion of the longest-ever single tunnelling contract awarded in London. The scheme will construct a new electricity superhighway far below the capital. This will meet increasing demand and help keep Londoners connected to safe and reliable electricity supplies.
Constructing access tunnels
The CSJV is responsible for the construction of around 32km of a high voltage electricity cable tunnel. This runs between Hackney and Willesden (via Kensal Green) Kensal Green and Wimbledon. Work also includes the construction of 14 access shafts (up to 40m deep and mainly between 12m and 15m in diameter) and associated head houses and culverts. Mechanical and electrical systems, including tunnel ventilation, communications and headhouse building services, are also part of the works.
The CSJV has also managed and co-ordinated the works with other principal contractors, including two main cable contractors, six substation contractors, an over-site residential developer at Earls Court and a third party substation developer.