UK Power Networks has partnered with Barhale to build a micro-tunnel under the Grand Union Canal in West London to deliver power for HS2.The tunnel will be used to carry power cables for HS2’s Tunnel Boring Machines (TBMs) set to build the high-speed rail line to Euston. UK Power Networks is providing HS2 with 45MVA of electricity supply to facilitate the construction of the high-speed railway.

Three new high voltage cable circuits around 3km in length will be energised to the Distribution Network Operator’s nearby substation which feed into the network that will power the manned TBMs. Each of the Euston TBMs weigh over 2,000 tonnes and measures 140m in length. They will be delivered to HS2’s Old Oak Common station site later this year and assembled ready for launch in the underground box.

To connect the circuits to its Old Oak Common substation, UK Power Networks appointed civil engineering, infrastructure and tunnelling specialist Barhale to drive a 125m long tunnel beneath the Grand Union Canal, reaching the company’s substation on Atlas Road.  6m diameter and 15m deep caissoned launch and reception shafts were constructed before an Akkermann TBM  was deployed to drive the 120m long tunnel beneath the canal. The 1500mm concrete tunnel was constructed from pipe jacked, pre-cast concrete sections.

The completion of the micro tunnel is a significant milestone for UK Power Networks and HS2 allowing for the final section of the 33,000-volt cable route to be completed. Works are expected to be completed in spring 2024.

Pamela Ali, programme manager, Capital Programme at UK Power Networks, said: “It has been a huge achievement to successfully and safely construct the micro-tunnel which will enable to install our circuits across the Grand Union Canal. A huge thank you to the HS2 and the Canal & River Trust for their support throughout.”

Niki French, head of utilities, HS2, said: “The delivery of this power tunnel is a critical part of our programme to build the new high-speed railway into the heart of London.  Through close collaboration and great teamwork, we have worked together to ensure the HS2 programme is maintained. It has been a pleasure working with the dedicated UK Power Networks team, who are always professional, helpful, and genuinely do care.”

Barhale’s regional manager Ovi Frunza said: “This microtunnelling project is another key piece in the HS2 jigsaw. “We are pleased to be able to continue to play our part in the continuing construction of HS2. We are involved in works at several sites along the route, including essential diversionary work at Ruislip and enabling works at the London terminus. “This will be the first time that we have worked with UK Power Networks and we are delighted to have secured the contract for this essential work. We are looking forward to building a long-term relationship.”

Jaione Echeveste, SCS Utilities, said: “HS2, UK Power Networks, and their contractors have been working collaboratively and relentlessly with key stakeholders to design and deliver this scheme. “The commitment and responsibility demonstrated by all parties throughout the project have stood out which have allowed us to achieve successfully this critical outcome.”