The first HS2 tunnel boring machine to work on the high-speed line in the Midlands launched on 2 December.
The TBM – Dorothy – will dig a one-mile tunnel under Long Itchington Wood in Warwickshire. During its construction and assembly, around 170 engineers worked on the tunnel boring machine, which weighs 2,000 tons and measures 125m in length. Now, an expert team will work in shifts around the clock for a period of five months until the tunnel bore is excavated.
“This is yet another vital landmark in our journey towards a better connected Britain and with the launching of Dorothy today in Warwickshire, shows real progress in helping transform journeys from across our country.”
This tunnel will be the first on the high-speed line to be completed. The TBM is scheduled to break through the first bore in spring 2022. It will then be disassembled and taken back to the north portal to dig the second bore, which is set to be completed at the start of 2023.
The purpose of putting HS2 in a tunnel along this section is to preserve the ancient woodland above, which is classified as a Site of Special Scientific Interest (SSSI).
“Today 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.”
Dorothy will remove 250,000 cubic metres of mudstone and soil. These will go to the on-site slurry treatment plant, where the material will be separated and then used on embankments and for landscaping along the line.
The final section at the tunnel’s southern end will become a cut and cover tunnel, where a soil roof is built around the tunnel entrance to allow it to be integrated in the natural landscape.
In total, ten tunnel boring machines will bore 64 miles of tunnel during Phase One of HS2.
This TBM was named after Dorothy Hodgkin, who became the first British woman to win the Nobel Prize in Chemistry. She confirmed the structure of penicillin and her work with insulin paved the way for it to be used on a large scale for the treatment of diabetes.
