National Grid is building a new network of cable tunnels, 32.5km in length, between Wimbledon and Crayford.
This project is the second phase of the scheme to rewire the Capital, called London Power Tunnels. It follows the success of the first phase, which was a seven-year, £1 billion programme, building 32km of tunnels and two new substations in North London.
We made a number of significant achievements on the original scheme including recycling 99% of spoil removed from the tunnel; designing a state-of-the-art substation at Highbury and a development to accommodate new business units and affordable homes; and working with over 30,000 pupils across London schools to promote engineering skills.
The second phase is essential in order to replace existing electricity cables in South London which are coming towards the end of their useful life, the majority of which are buried beneath the road network.
- The three sections we are replacing are:
- Section 1: Wimbledon to New Cross – Operational by: 2025
- Section 2: New Cross to Hurst – Operational by: 2026
- Section 3: Hurst to Crayford – Operational by: 2024.
The tunnel will be up to four metres in diameter and help to ensure a secure supply of electricity for the London in the future. We are building shafts and headhouses at key locations across the route to facilitate access and provide ventilation for the tunnels. The seven new shafts will help build the tunnel and the headhouses will cover the shafts once the tunnel is built.
Construction will start in March 2020 and take approximately six years to complete.
The advantages of building tunnels are:
- Overall disruption to Londoners and road users during construction will be minimal as the majority of the works will take place deep underground
- Future repair and maintenance can be carried out with minimal disruption to traffic, businesses and residents
- Additional capacity can be made available if required in the future to meet increasing demand.
National Grid recently held information events for its Kings Avenue site, Old Kent Road site (New Cross substation), and Hurst site, details of which can be viewed here.