INFRASTRUCTURE

UK Power Networks and Barhale build tunnel to power HS2 construction to Euston

Micro-tunnel under the Grand Union Canal in West London to support HS2 main tunnelling completed

One of the launch and reception shafts constructed by Barhale to allow an Akkermann TBM to be deployed to drive a 120m long tunnel beneath the Grand Union Canal in London Credit: Barhale

One of the launch and reception shafts constructed by Barhale to allow an Akkermann TBM to be deployed to drive a 120m long tunnel beneath the Grand Union Canal in London Credit: Barhale

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 new UK high-speed rail network.

The tunnel will be used to carry power cables for HS2's 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 feeds into the network that will power the manned TBMs. Each of the Euston TBMs weigh over 2000t and measures 140m in length. They will be delivered to HS2's Old Oak Common station site 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. The 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 33,000V cable route to be completed.

This microtunnelling project is another key piece in the HS2 jigsaw

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 us 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."

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."