HS2’s Mary Ann TBM Begins 3-Month Dismantling After Tunnel Completion

The first tunnel boring machine (TBM) deployed on the HS2 Bromford Tunnel project has completed its excavation assignment and is now being disassembled for refurbishment. Known as Mary Ann, the 125-meter-long, 1,600-tonne machine operated for 652 days to excavate the initial 5.8-kilometer bore between North Warwickshire and Birmingham.

On May 30, the 8.62-meter diameter cutterhead, weighing 120 tonnes, was lifted from the 22-meter-deep portal at Washwood Heath using a 700-tonne crawler crane. This marked the beginning of a three-month dismantling operation carried out by a 15-member engineering team. Once disassembled, the machine will be transported to its original manufacturer in Germany for refurbishment and adaptation to new project requirements.

This development is part of the broader HS2 Phase One, with Bromford Tunnel being a major element of the rail route passing through the Midlands. A second TBM, named Elizabeth, is currently active on the parallel bore and is expected to complete its work later in 2025.

Following is a video footage showcasing the tunnel's (Mary Ann) milestone breakthrough.