A 2,000 tonne tunnel boring machine (TBM) that is paving the way for the HS2 London-Birmingham high-speed line has made its first breakthrough after eight months of drilling underground.
Emerging in Long Itchington Wood near Stratford-on-Avon in Warwickshire late last week, the tunnel boring machine nicknamed Dorothy has completed the first of 64 miles of intermittent tunneling between London and Manchester.
The 125m-long machine and its 400-man tunnel-digging crew have been busy installing 790 concrete rings underground since they began their journey at the tunnel’s north portal in December 2021.
The work is being carried out by Civil Main Works Contractor HS2 Balfour Beatty Vinci (BBV JV)
The machine, one of 10 custom-built for the project, is named after Dorothy Hodgkin, who in 1964 became the first British woman to win the Nobel Prize in Chemistry.
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The tunnels were designed with the aim of protecting ancient forests and their ecosystems, integrating with the natural landscape by reusing excavated materials as an earthen roof around the tunnel entrance.
A 254-meter-long conveyor at the North Portal removes remaining excavated material from the site above the Grand Union Canal.
Long Itchington Wood is listed as a Site of Special Scientific Interest and the plan is contested by environmental activists who have criticized the destruction of some forests.
HS2 Minister Trudy Harrison described the news as “literally, a groundbreaking moment” for the scheme. She said it demonstrated the government ‘continues to deliver on its promises and advance our transformation plans to boost transport, bring communities together and level the North and Midlands’.
Over the next four months, the cutterhead and front end of the machine will be dismantled and brought back to the North Portal.
The bulk of the TBM will be brought back through the tunnel to be reassembled ready to be launched on the second borehole of the tunnel.