The team from the National Grid's London Power Tunnels project celebrate their latest breakthrough

National Grid’s £1bn London Power Tunnels project achieves ‘major milestone’

National Grid’s London Power Tunnels (LPT) project has achieved a ‘major milestone’ with its final tunnelling breakthrough at Eltham substation in Greenwich.

The last of the project’s massive tunnel boring machines (TBMs), named ‘Grace’, broke through on Saturday, having tunnelled over 11km eastwards from National Grid’s New Cross substation in Southwark.

All 32.5km of the project’s underground route are now complete, with installation of 200 km worth of high voltage cable, enough to stretch from London to Cardiff, already underway between substations at Wimbledon and Crayford.

In total the project will have shifted 900,000 tonnes of earth, equivalent in volume to half of Wembley Stadium, with 99.98 per cent of waste material diverted from landfill.

The LPT project’s newly installed transmission infrastructure is due to be fully operational by 2026, with the aim of reinforcing and future-proofing London’s electricity network, and supporting Britain’s transition to net zero, as demand in the capital grows.

Construction of the tunnels began in March 2020 with the tunnelling works undertaken by National Grid’s delivery partner HOCHTIEF-Murphy Joint Venture.

Alice Delahunty, President of National Grid Electricity Transmission, commented: “Our London Power Tunnels project has achieved a lot since it kicked off in 2020, but the final tunnelling breakthrough at Eltham is a particularly remarkable moment.

“This complex engineering endeavour is now really taking shape, with completion of tunnelling now physically linking our sites across South London for the first time and meaning we can move on to the next chapter to progress our vital cabling work.

“The outstanding effort by our project teams and suppliers is strengthening London’s electricity network and making sure it safely, reliably and efficiently powers homes and businesses in the capital for years to come.”

Santiago Daniele, HMJV Project Director, added: “It’s been an incredible journey so far, from taking over our tunnel drive sites a week after the Covid lockdown, to sinking eight shafts and undertaking five tunnel drives with four TBMs over the past three and half years.

“With our final TBM drive breaking through at Eltham ahead of the original baseline programme, it’s testament to the collaboration, ingenuity and fantastic joint culture of all involved, despite all of the challenges faced.”

By Matthew Neville – Senior Correspondent, Bdaily