Breakthrough for HS2 as first Birmingham tunnel section dug

HS2 has hit a major construction milestone with the breakthrough of its first Birmingham tunnel, completing the initial 3.5-mile bore of the Bromford Tunnel.

Giant tunnel boring machine Mary Ann smashed through at Washwood Heath today, marking the end of a 652-day drive beneath the M6, River Tame, and critical National Grid infrastructure – all completed without disruption.

The 125m-long TBM was launched in July 2023 by Balfour Beatty Vinci.

Its crew of 450 specialist tunnellers worked around the clock to steer the 1,600-tonne machine through complex ground conditions at depths of up to 40m.

At peak, Mary Ann advanced 30m per day, installing nearly 3,000 concrete rings made up of segments cast at BBV’s Avonmouth factory.

BBV tunnelling director Jules Arlaud said: “It’s been a challenging drive beneath critical live infrastructure. I’m incredibly proud of our entire team, whose dedication made this possible.”

Around one million tonnes of spoil has been reused on HS2’s Delta Junction viaduct complex, helping cut lorry movements via dedicated haul roads.

HS2 CEO Mark Wild stands in front of the TBM Mary Ann at breakthrough in Birmingham

HS2 chief executive Mark Wild said: “Today’s breakthrough is a significant milestone for the project. Washwood Heath is set to become one of the most important sites on the entire HS2 network.”

The site will house HS2’s train depot and Network Integrated Control Centre. It’s also at the heart of a wider £10bn wave of regeneration and investment across the West Midlands.

More than 10,000 people in the region are now working on HS2, including 710 apprentices and 1,870 previously unemployed recruits. Over 400 local businesses are supplying the project.

Second TBM Elizabeth is now advancing through the parallel bore, due to complete later this year.