National Grid is an electricity and gas company that connects consumers to energy sources through its networks. In Britain, National Grid runs the gas and electricity systems that society is built on, delivering gas and electricity across the country. In the North Eastern US, it connects more than seven million gas and electric customers to vital energy sources, essential for our modern lifestyles.

The Woodhead Cable Tunnel is a disused Victorian railway tunnel under the Pennines, used to carry 400kV HV cables, forming a strategic link in the UK’s electricity network. With these older cables reaching the end of their lifespan, Balfour Beatty Utility Solutions was awarded the contract to install new cables in another, parallel disused tunnel, originally built by the company in the late 1950s.

Traditionally, a cable installation of this nature would be extremely labour intensive, involving dozens of operatives using conventional bond methods pulling the cable down the tunnel. This means exposing operatives to wire bounds under tension. The challenge for Balfour Beatty Utility Solutions was to find an innovative new way of cable installation increasing safety, quality and productivity.

An innovative new technology was developed by Balfour Beatty Utility Solutions to meet these challenges. The widely acclaimed Tunnel Cabling Machine (TCM), allowed a team of 10 to conduct the installation, automating the cable pulling and placing process (a process which would usually require 40 operatives) whilst providing a stable working platform for working at height. By automating the process, quality of installation could be guaranteed with no stress put on the cable during the pulling process.

The Woodhead Tunnel project represents not only an essential upgrade to this vital piece of the UK’s electricity grid, but also a step change in the cable installation process for tunnel projects. The TCM used at Woodhead has given rise to a family of machines for other projects, including the Croydon Tunnel and the future London Tunnels project.