HS2 has revealed the first images of the TBM that contractor Balfour Beatty VINCI JV will use to bore the 5.6km long Bromford Tunnel, between Water Orton in North Warwickshire and Washwood Heath in Birmingham. This is the fourth twin bore railway tunnel to start construction on Britain’s biggest infrastructure project. The tunnel will take high speed trains into Birmingham as they approach Curzon Street Station in the heart of the city.
The tunnelling team will operate the TBM 24/7, with each bore taking around 16 months.
Neil Johnson, Balfour Beatty VINCI’s Health, Safety, Wellbeing and Tunnels Director, said:
“The excitement among the tunnelling team at our Bromford site has been growing for months as we’ve worked hard to prepare for yet another huge moment on the HS2 project. The whole team is proud to reach this next big milestone.
“We were particularly pleased that our new tunnelling apprentices will be able to develop their skills as the TBM progresses – what an amazing opportunity for them.”
After final testing, the Herrenknecht TBM will launch from a 160m x 30m wide x 15m deep underground structure which forms the east portal of the tunnel. Over the last few months, sections of the machine – including the 8.62m diameter cutterhead – were lowered into the box where it was assembled.
A total of 20,797 segments will be put in place by the TBM, making 2,971 concrete rings to form the tunnel. Each segment is 2m wide and 35cm thick, with each completed ring weighing around 49 tonnes.
The TBMs will remove 1.87M tonnes of excavated material, which will be sifted at the on-site slurry treatment plant and reused on nearby sites at the Delta Junction.