HS2 unveils the Bromford Tunnel TBM named 'Mary Ann'.

Bromford Tunnel

Bromford Tunnel is a 3.5 mile (5.6km) twin-bore high-speed rail tunnel. Two huge tunnel boring machines (TBMs) are being used to dig it between Water Orton in North Warwickshire and Washwood Heath in Birmingham.

The TBM that is being used to dig the first bore is called ‘Mary Ann’ after Mary Ann Evans, better known by her pen name George Eliot, who was an English novelist, poet, journalist, translator and one of the leading writers of the Victorian era. The name was suggested by the Warwickshire community. TBM Mary Ann was launched in August 2023.

The TBM that is being used to dig the second bore is called ‘Elizabeth’ after Dame Elizabeth Cadbury, who spent her life campaigning for the education and welfare of women in Birmingham. Pupils from Paget Primary School in Birmingham chose the name and TBM Elizabeth was launched in March 2024.

The tunnelling operation is being delivered by around 450 people working for HS2’s contractor Balfour Beatty VINCI. The expert tunnelling team will operate the TBM 24/7, with each bore taking around 16 months. 1.87 million tonnes of material will be excavated and sifted at the on-site slurry treatment plant to be reused on nearby sites at the Delta Junction viaduct.

Watch on YouTube - Huge HS2 tunnelling machines digging towards Birmingham

HS2 tunnelling in West Midlands

Infographic map showing a below ground view of the HS2 tunnels in the West Midlands.

Bromford Tunnel Transport and Works Act Order Application

We are applying for some additional consents for specific, technical aspects of the plans. In particular, we are seeking to amend the wording in the Act to remove the requirement for the construction of the railway, ‘partly on viaduct’, in this location, as part of work no 3/157 (please see attached plan in appendix A). This will no longer be applicable, as the railway will now be in tunnel.

This specific change involves applying for an Order under the Transport and Works Act 1992, as part of the design change from viaduct to tunnel.

On 20th January 2022, HS2 Ltd. submitted a Transport and Works Act Order application for the High Speed Rail (London – West Midlands) Act 2017 (Amendment) (Bromford Tunnel) Order 202[X].

The Order would make a minor amendment to the High Speed Rail (London – West Midlands) Act 2017 (“the 2017 Act”) which authorises the construction and operation of Phase One of the proposed high speed railway between London and the West Midlands which is approximately 230km (143 miles) in length.

View our Bromford Tunnel Transport and Works Act Order Application documents.

Benefits of the Bromford Tunnel extension

Reduction of construction

Increasing the length of the tunnel from 2.8km to 5.7 km will remove the need for complex engineering above ground in an already built-up and environmentally sensitive area, including a series of retained cuttings, retained fills and a viaduct
Park Hall Nature Reserve will have a significantly reduced level of construction as we will no longer need to clear ancient woodland or divert the River Tame at this location

Less land required

There will be less land required in the Castle Bromwich Business Park area, meaning that fewer properties and businesses will be affected by the new railway line. This will save a number of jobs in the area

Reduction of construction traffic

Extending the tunnel reduces construction traffic on the road network in Birmingham. Instead of transporting spoil from Bromford along the local road network, we will transport it from Water Orton along purpose-built construction haul routes. These materials will be used locally near the Water Orton Flyover and along the Marsh Lane embankment
There will be up to 260,000 fewer HGV movements over the course of construction, which will help to minimise our impact on the environment

The eastern portal (Water Orton)

The eastern portal of the tunnel will be located off Attleboro Lane in Water Orton. The design of the portal is ongoing. We will keep local communities up to date as the design progresses.

A compound will be used to construct the tunnel, to store materials and serve as a base for our workforce. It will be accessed via purpose-built haul roads. The previously proposed substation is now being progressed at a different location off the Birmingham Road.

To minimise the noise of trains as they exit the tunnel, we will be constructing a porous portal. On high-speed railways, the purpose of a porous portal is to ensure that the waves produced by the ‘piston effect’ of the train moving at speed, which can otherwise result in noise as the train exits the tunnel, are kept at a level which does not adversely affect the surrounding area. A porous portal is generally achieved by providing perforated structures, usually of concrete, at the tunnel entrances.