TBM Elizabeth will dig the second bore of HS2’s Bromford Tunnel, between the east portal at Water Orton in North Warwickshire and the west portal at Washwood Heath in Birmingham.
The 3.5-mile twin bore tunnel will take high speed trains in and out of Birmingham, with a series of viaducts between Washwood Heath and Curzon Street Station taking trains to the city centre.
The first TBM, named Mary Ann – the real name of Warwickshire-born author George Eliot – launched in June 2023 and has completed around one third of her journey towards Birmingham. So far, Mary Ann has tunnelled under the Park Hall Nature Reserve, is currently near the River Tame, and will continue adjacent to the M6 at a depth of 27 metres before breaking through at Washwood Heath later this year.
TBM Elizabeth set out on Tuesday 5th March and is scheduled to finish her journey in autumn 2025. Elizabeth is named the philanthropist and reformer Dame Elizabeth Cadbury, who married into the Birmingham chocolate family.
Both TBMs will put a total of 41,594 concrete segments in place, creating 5,942 rings to make the twin bore tunnel, with each ring weighing 49 tonnes. The segments are produced at BBV’s pre-cast factory at Avonmouth near Bristol.
The full Bromford Tunnel programme is being delivered by around 450 people working for HS2’s contractor Balfour Beatty Vinci (BBV). A specialist tunnelling team working for BBV’s subcontractors Tunnelcraft and Solihull-based Rorcon are operating both TBMs 24/7, with each bore taking around 16 months.
BBV tunnelling director Jules Arlaud said: “Today marks Balfour Beatty Vinci’s fourth and final TBM launch – an incredible moment for our tunnelling team who have worked tirelessly to achieve this milestone. As Mary Ann continues her journey towards Washwood Heath in Birmingham, we’re now looking forward to having two machines underground, as this fascinating and complex stretch of the HS2 route inches another step closer to completion.”
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