HS2‘s 1600-tonne tunnel boring machine (TBM) has now completed half of the excavation and building work for the Bromford Tunnel in Birmingham.

The tunnelling machine, named ‘Mary Ann’, started boring at Water Orton and is scheduled to break through at Washwood Heath in 2025.

The tunnel will be a total of 3.5 miles long and pass under Park Hall Nature Reserve, the River Tame, Castle Vale and the M6.

There is also a second tunnel boring machine, called ‘Elizabeth’, which is currently working on the tunnel’s second bore and is expected to finish by the end of 2025.

Both of the machines build the tunnel whilst they excavate, and in total will remove 1.87 million tonnes of material.

This excavated material is being sifted on site and then transported for further use to Delta Junction, where a series of viaducts is being built in order to take trains from the tunnel through to Curzon Street Station.

‘Mary Ann’ is being manned by a round-the-clock group of tunnelling engineers who are supervising the building of the 2,971 concrete rings which will form the tunnel.

News that the Bromford Tunnel has reached its halfway point follows on from the Northolt Tunnel in London reaching the same milestone in July of this year and the Thame Valley Viaduct in Buckinghamshire achieving this in May.

The project is being carried out by specialist UK-based tunnelling firms Tunnelcraft and Rorcon.

We’re now at peak construction in the West Midlands, and it’s great to celebrate the halfway point for the ‘Mary Ann’ tunnel drive into Birmingham. By the end of next year, both of these tunnels will be built, marking a significant step in HS2’s construction in the region.

Around 31,000 people are working on HS2, with around a third of these in the West Midlands including 615 apprentices and over 1,650 people who were previously unemployed, providing a unique opportunity for local people to learn new skills while delivering the UK’s largest construction programme.

Steve Powell, HS2’s Head of Delivery