First TBM breaks through at HS2 in London

London’s High Speed 2 (HS2) rail project celebrated its first tunnel breakthrough with the 2 kt (2,200 st) tunnel boring machine broke through on the London to Birmingham route in July.

The TBM began boring its 1-mile journey in 2021 underneath an ancient Warwickshire wood and became the first project of HS2 to breakthrough. Work is being done in a bid to preserve the ancient woodland, officials say.

Sky News reported that the TBM, Dorothy, named after Dorothy Hodgkin – the first woman to win a Nobel Prize in chemistry in 1964 – is the first tunnel breakthrough on the London to Birmingham route.

HS2 minister Trudy Harrison described it as “quite literally, a ground-breaking moment” for the scheme.

She said it demonstrated the government was “getting on with delivering on our promises and progressing our transformative plans to boost transport, bring communities together and level up the North and Midlands.”

However, the scheme is opposed by environmental activists including Stop HS2, which criticized the destruction of woodland and argues more investment in short commuter rail services is needed.

Long Itchington Wood is classified as a site of special scientific interest (SSSI) and has ecosystems that have taken hundreds of years to establish, the HS2 team behind the work said.

Nearly 400 people working for HS2’s main works civils contractor Balfour Beatty VINCI (BBV JV) have delivered this important milestone on the HS2 project.

The tunnelling team have been working around the clock in shifts for seven months to operate the TBM, which has put 790 concrete rings in place, with each ring made from eight, 2-m long segments.

HS2 Ltd’s CEO Mark Thurston said: “This is a historic moment for the HS2 project, and I’d like to congratulate everyone involved in delivering it. The 400-strong team, including tunnelling engineers, TBM operators and the construction workers at both portal sites, have pulled out all the stops to achieve this fantastic milestone.

“This milestone demonstrates the significant momentum behind Britain’s new zero-carbon railway, creating thousands of jobs and apprenticeships, along with hundreds of opportunities for businesses right across the country, helping fuel our economic recovery.”

Over the next four months, the cutterhead and front section of the TBM will be dismantled and transferred back to the north portal, while the bulk of the machine will be brought back through the tunnel. It will be reassembled, ready to launch for the second bore of the tunnel.