London Power Tunnels

London accounts for 20% of the UK's energy use and demand is steadily rising

The background

In 2013, Balfour Beatty began to install high voltage electricity cables for National Grid's London Power Tunnels project.

This project will rewire the capital via deep underground tunnels, in order to ensure London’s electricity needs continue to be met and to ensure the city can access the renewable energy sources of the future. It will connect several substations around the city via tunnels up to 60 metres below the surface.

Putting power cables in tunnels also means that future maintenance and network expansion operations can be carried out with minimum disruption. Electricity cables in cities are traditionally buried in ducts just below the road surface, so fault repair or cable upgrades often cause lengthy delays for road users.

The challenge

We are investing in training in order to grow a sustainable, long-term workforce, at the same time as developing innovative new technologies to ensure our people stay safe.

The measures

Working with the Tunnelling and Underground Construction Academy in Ilford, East London, we are helping to address the resource challenges facing the power industry by offering local unemployed people training in tunnelling and the opportunity to work on this important infrastructure project.

Our patented Tunnel Cabling Machine (TCM) technology is another vital part of our approach to cable tunnel projects. The TCM has revolutionised the process of installing high voltage cables within tunnels by - driving out risk and vastly increasing the speed, efficiency and quality of installation. On previous projects, this technology has reduced project timescales by a third and has carried the longest single-length cable-pull in Europe – 1.2km.

The benefits

The London Power Tunnels project reaffirms Balfour Beatty's position as one of the world's leaders in tunnel cable installation, a sector which is likely to grow as developing economies continue to invest in new approaches to infrastructure.

London Power Tunnel 2

In 2021, Balfour Beatty was awarded the second phase of this ambitious scheme to rewire London and connect with the capital. The £52 million contract will include installing 200km of 400kV cables within a 32.5-kilometer tunnel network, deep below the ground between Wimbledon and Crayford.