UK Power Networks has partnered with tunnelling specialists Barhale to dig a micro-tunnel under the Grand Union Canal in West London, delivering power for the London end of the HS2 rail link.
The tunnel will carry power cables for HS2’s Tunnel Boring Machines (TBMs), engaged on building the high-speed rail line to Euston. UK Power Networks is providing HS2 with 45MVA of electricity supply to facilitate the railway’s construction.
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 engaged tunnelling specialist Barhale to drive a 125 metre tunnel beneath the Grand Union Canal, reaching the company’s substation on Atlas Road.
Shafts six metres wide and 15 metres deep were dug and reinforced. Then 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 coming weeks.
Pamela Ali, a capital programme manager for UKPN said: “It has been a huge achievement to successfully and safely construct the micro-tunnel. It will enable to install our circuits across the Grand Union Canal”
Niki French, head of utilities at the rail company, said: “The delivery of this power tunnel is a critical part of our programme to build the new HS2 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.”
