After completing its 3.5-mile underground journey beneath North Warwickshire and Birmingham, the massive HS2 tunnel boring machine (TBM) known as Mary Ann is being dismantled for reuse in another project.
The machine finished digging the first bore of the Bromford Tunnel and is now in the early stages of disassembly. On Friday, May 30, 2025, a key milestone was reached as its 8.62-metre wide cutterhead was lifted from the 22-metre-deep tunnel portal at Washwood Heath in north Birmingham. The 120-tonne cutterhead was hoisted into the skyline using a powerful 700-tonne crawler crane. The lift was completed in just 90 minutes.
Over the next three months, a team of 15 engineers will continue dismantling the 125-metre-long, 1,600-tonne TBM. The work is taking place beside the Washwood Heath portal before the machine is sent back to its manufacturer, Herrenknecht, in Germany.
Mary Ann spent 652 days and nights tunnelling through the earth. Now, she will be refurbished and modified to suit the technical needs of her next mission.
Meanwhile, TBM Elizabeth is continuing work on the second bore of the Bromford Tunnel. That breakthrough is expected to happen later this year.
