Construction of major underground tunnel, 3km in length to link substations between South East London, the City and East London.
The construction of the 3.5km underground tunnel was completed on programme and through improved innovation, provided cost savings of c. £4m to the project. Despite the tight urban environment and sensitive nature of works, we were able to deliver the project safely and with minimal disruption to the public and other key stakeholders, TfL and Network Rail. The project was a major milestone in UKPN’s continuous capital programme to develop and meet the capital’s increasing energy needs and to improve resilience across the network.
Despite challenging geological conditions, the tunnel was constructed successfully through a refurbished Earth Pressure Balance (EPB) Tunnel Boring Machine (TBM). Further challenges presented due to the small size of the site (70m x 20m) and the close proximity to private housing.
We developed a bespoke methodology where the cable reeler stand was lowered into shaft and placed on the bottom. The cable drum was then lowered and positioned onto the cable reeler and was electrically power fed from a local power point via leads. The cable end was attached to steel arm fixed to a battery operated tunnel tug vehicle to pull the cable. It was then fed through a series of rollers from the bottom of the shaft through to the chamber and into the tunnel. To ensure that the pulling of the cable was never exceeded during the installation process, a tension meter was used to monitor force. This achieved benefits to project through increased productivity and a safer, more controlled installation.
Project of the Year (up to £50M) and ITA Tunnelling Awards 2017.
Kilometres of power cables installed
Man hours accident and RIDDOR incident free
Metres below ground the tunnel shaft was constructed
Murphy is a multi-disciplinary specialist in the Transportation sector, working across rail, highways, aviation and ports to deliver sustainable solutions. From renewals to electrification, bridge building, highways and aviation, our award-winning team has extensive experience.