A £7 million high-voltage cable replacement project in South London has used horizontal directional drilling to install new electricity infrastructure beneath active railway and tram lines while services continued above.
The project, running from Sydenham Park to Churchfields, has installed nine kilometres of new 33,000-volt underground cables to upgrade critical electricity infrastructure and help ensure reliable power supplies for the local community.
One of the most significant parts of the route involved installing cables underneath the railway and tram lines at Avenue Road Station.
The project team used horizontal directional drilling (HDD), a specialist technique that allows cables to be installed safely beneath railway infrastructure without major excavation. A 50cm tunnel was created beneath the railway, allowing ducts and cables to be installed while rail and tram services continued to operate above.
By using an underground bore, the technique also helped reduce disruption for passengers, road users and the local community.
The new cross-linked polyethylene cables will upgrade the local electricity network, helping to provide safe and reliable electricity supplies for thousands of customers.
The project also supports UK Power Networks’ commitment to environmental stewardship, aligning with the Groundwater Regulations 2009 and relevant industry standards. Spare ducts are also being installed to future-proof the network and facilitate further upgrades.
The work is being closely coordinated with the £20 million Beddington-Sydenham 132,000-volt project to maximise efficiency and minimise disruption for residents and businesses.
Jason Callaghan, Project Manager at UK Power Networks, says, “We’re installing modern cross-linked polyethylene cables, future-proofing the network and delivering a more resilient supply for our customers.
“The main driver for the project is to upgrade the cable circuits between Sydenham Park and Churchfields. It’s a major step forward for local network reliability. There has been close liaison with Transport for London, Network Rail and the council to carry out the HDD effectively.”
Claire Sheridan, Portfolio Manager, says, “We’re investing around £30 million to replace 132,000-volt and 33,000-volt cables between Sydenham Park and Churchfields and Beddington and Sydenham. It’s an extremely busy route with lots of other utilities’ equipment underground, and above ground we are squeezed between residential streets, tramlines and an active railway.
“The HDD is a complex engineering operation that keeps the trains running and the streets open while the works take place. First, we drill a small pilot hole, then we progressively widen it four times in order to achieve the correct diameter to pull the ducts through. We pulled the ducts through beneath the railway, keeping a safe distance from homes and track.”
Fintan McCusker at McCormack Drilling says, “This was a challenging project given the tight suburban location, railway infrastructure and utilities to be negotiated by HDD. Our team worked closely with UK Power Networks and Clancy to develop a workable solution to the many engineering challenges at this location. It required meticulous attention to detail right through from feasibility, design and planning to installation.”
Richard Fisher, Client Delivery Lead within the Savills Utilities and Infrastructure team, says, “Working alongside UK Power Networks Major Projects Consents and Stakeholder Engagement teams in a complex urban environment, Savills Land Assembly and Building & Project Consultancy teams provided a suite of services to support the successful delivery of this project.
“Close coordination between teams across UK Power Networks, Savills and delivery contractors was essential in securing the necessary consents and maintaining relationships with stakeholders throughout the project.”
