Mary Ann started work on the project in July 2023.
The Bromford Tunnel extends from Water Orton in Warwickshire to Washwood Heath in north-east Birmingham. Once completed, it will be the longest railway tunnel in the West Midlands, helping to reduce congestion on the West Coast Main Line. A team of 450 BBV workers completed this phase in under two years, with the second bore,_led by TBM Elizabeth, expected to finish later in 2025.
Jules Arlaud, BBV’s tunnelling director, stated: “Today’s breakthrough is a significant moment for Balfour Beatty VINCI, as we celebrate the arrival of our first tunnel boring machine into Birmingham. It’s been a challenging drive beneath critical live infrastructure and through complex ground conditions. I’m incredibly proud of our entire team, whose expertise, dedication and resilience has made this possible.”
The 1,600-tonne TBM operated at depths of up to 40m, navigating beneath natural reserves, motorways, and the River Tame. It advanced approximately 30m daily, using 20,797 precast concrete segments—each weighing up to 7 tonnes—produced at BBV’s Bristol factory to form 2,971 concrete rings. The excavated one million tonnes of spoil are being reused for the nearby Delta Junction, aligning with HS2’s sustainability goals.
The Washwood Heath site, where Mary Ann emerged, will serve as HS2’s operational hub, hosting the Depot and Network Integrated Control Centre for train servicing, storage, and real-time railway management. The project has also boosted local employment and skills development, contributing to the region’s economy.
Following excavation, the focus will shift to installing infrastructure such as cross passages, concrete finishing, base slabs, and emergency walkways. The Bromford Tunnel is one of three key HS2 sites in the West Midlands, alongside new stations in Birmingham and Solihull, supporting regional connectivity and growth.
