By rosebell
Following excavation of the first bore of the Bromford Tunnel reaching the halfway point, building of HS2’s connection to Birmingham has reached a landmark.
Currently 2.8km of the twin-bore tunnel, that is due to take trains into Birmingham as they approach Curzon Street Station in the heart of the city, has been constructed by TBM Mary Ann, which was commissioned from Water Orton in June 2023.
While this TBM dug almost 30m underground towards Washwood Heath in Birmingham and passed beneath the Park Hall Nature Reserve and River Tame, it is now passing under Castle Vale. Before breaking through at Washwood Heath early next year, it will drive adjacent to and under the M6 motorway.
With125m length and 1,600 tonnes weight, TBM Mary Ann was after named Mary Ann Evans, the real name of Warwickshire-born writer George Eliot, and is operating by HS2 contractor Balfour Beatty Vinci (BBV).
TBM Elizabeth is the second TBM for construction of the Bromford Tunnel and was launched in March this year. Including the gantries and the centre part of the cutterhead, The majority of this machine’s components have been reused from TBM Dorothy which completed the 1.6km twin-bore Long Itchington Wood Tunnel in Warwickshire previous year.
TBM Elizabeth is named after Dame Elizabeth Cadbury who campaigned for the education and welfare of women in Birmingham.
In order to constructing the twin-bore tunnel, Mary Ann and Elizabeth will install a total of 41,594 concrete segments, creating 5,942 rings. Each ring weighs 49 tonnes, whereas the segments are being produced at BBV’s pre-cast factory at Avonmouth near Bristol.
