The first HS2’s tunnel boring machine (TBM) in the Midlands has been launched under Long Itchington Wood in Warwickshire as part of the Phase One of Britain’s high speed rail line between London and Birmingham. The TBM will dig a one-mile (1.6 km) in the next five months.
This “is another major milestone for HS2. You can see the real progress the project is making as we launch this TBM on one of HS2’s largest sites in the Midlands, contributing to massive job creation in the region,” HS2 CEO Mark Thurston said when pushed the start button.
This will be the first HS2 tunnel to be completed on 225 km line, with the machine set to break through its first bore at the south portal in Spring 2022. It will then be disassembled and taken back to the north portal to dig the second bore, which is due to be completed in early 2023.
The TBM will remove a total of 250,000 cubic metres of mudstone and soil which will be transported to the on-site slurry treatment plant where the material is separated out before being reused on embankments and landscaping along the route.
The launching of HS2’s tunnel boring machine is another vital landmark in our journey towards a better connected Britain (…). It also underlines how our GBP 96 billion [EUR 113 billion] Integrated Rail Plan – the largest ever investment in our rail network – is instrumental in creating jobs and economic opportunities, and ensuring more people reap the benefits of better rail journey,” HS2 Minister Andrew Stephenson added.
The 2,000 tonne, 125m long TBM Dorothy will preserve the ancient woodland above, which forms a key element in how HS2 is managing environmental impacts through the design of the railway. These woods are classified as a Site of Special Scientific Interest (SSSI) and have complex ecosystems that have taken hundreds of years to establish.
The final section at the south end of the tunnel will become a ‘green tunnel’, also known as a cut and cover tunnel, where a soil ‘roof’ is built around the tunnel entrance to integrate the portal into the natural landscape.
In May, the TBM Florence was launched to dig 16 km of tunnel under the Chilterns to create the connection between London and the West Midlands.