First HS2 tunnel breakthrough in Birmingham
HS2 has completed its first major tunnelling breakthrough in Birmingham, marking a significant milestone in the construction of the 3.5-mile Bromford Tunnel that connects Water Orton in Warwickshire with Washwood Heath in the northeast of the city.
The 125-metre-long tunnel boring machine (TBM), named Mary Ann after Warwickshire-born author George Eliot, broke through on 9 May 2025 following a 22-month journey beneath major infrastructure including the M6 motorway, the River Tame and Park Hall Nature Reserve. The breakthrough marks HS2’s first completed tunnel bore in the West Midlands.
Civil engineering contractor Balfour Beatty VINCI led the tunnelling works, supported by a 450-strong crew working around the clock to navigate challenging geology and safely steer the 1,600-tonne machine at depths of up to 40 metres. Mary Ann excavated roughly one million tonnes of material, which is being reused for construction works at the nearby Delta Junction.
HS2 CEO Mark Wild hailed the breakthrough as a pivotal moment: “Today’s breakthrough is a significant milestone for the project and I’m immensely proud of the men and women who have worked day and night to bring Mary Ann and her crew home safely.”
The precast concrete segments used to line the tunnel were produced by Balfour Beatty VINCI’s factory in Avonmouth. In total, Mary Ann installed 20,797 segments to create 2,971 concrete rings during the drive. The second bore will be completed by sister TBM Elizabeth later this year.
The Washwood Heath site—where Mary Ann emerged—will become the operational heart of the high-speed railway, housing the HS2 Depot and Network Integrated Control Centre. HS2 is also delivering new stations at Birmingham Curzon Street and Interchange in Solihull.
Balfour Beatty VINCI tunnelling director Jules Arlaud said the achievement reflects years of planning and collaboration: “It’s been a challenging drive beneath critical live infrastructure and through complex ground conditions. I’m incredibly proud of our entire team.”
HS2 reports that around 10,000 people in the West Midlands are now working on the project, including 710 apprentices and nearly 2,000 individuals who were previously unemployed. More than 400 local businesses are also active in HS2’s regional supply chain.
As the UK's largest infrastructure project, HS2 is designed to cut journey times between London and Birmingham to 49 minutes and significantly increase capacity on the rail network. The completed railway will be powered by zero-carbon electricity and monitored via embedded real-time sensors for predictive maintenance and safety.
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