National Grid London Replacement Cable Tunnels.

Energy company National Grid has awarded an eight year contract to Costain for the construction of two deep cable tunnels in London.

The new tunnelled cable network that National Grid will build under London will help to meet the increased energy flows across the city.

The contract includes the design and build of two cable tunnels between 3m and 4m in diameter, running between 20m to 60m below ground. The first 20 km tunnel will run from National Grid’s substation at Willesden in North West London via Kensal Green, St. John’s Wood and Islington to the substation at Hackney in East London, close to the new Olympics site. 

The second 12 km tunnel will run south from Kensal Green to the substation at Wimbledon in South West London. 

Works will start later this year, with the tunnelling being completed by the end of 2014 and the full energisation of the new cables anticipated by November 2018.

Herrenknecht Formwork has been awarded the contract for the supply of segment moulds for lining of parts of these two cable tunnels.

Scope of supply:

• 30 sets of segment moulds including vibration 
• 2 demoulding hooks