The Bromford tunnel is being delivered by HS2’s main works contractor Balfour Beatty VINCI (BBV).

Two identical machines were used to dig the 3.5-mile long Bromford tunnel that will carry high speed trains under the M6 and eastern outskirts of the city, with the first one – Mary Ann – breaking through earlier this year. Together, Elizabeth and Mary Ann have excavated more than 1.8 million tonnes of material and installed 5,804 concrete ring segments for the twin, eastbound and westbound tunnels. The spoil – made up of various grades of Mercia Mudstone – is being used to landscape the railway on the approaches to the city.

Construction teams are now mainly focused on internal walkways, ventilation shafts and cross passages. The TBM Elizabeth will now be removed from the tunnel to allow work to progress on the concrete finishing works, base slabs, and emergency and maintenance walkways.

HS2’s eight TBMs have now finished excavating the 28 miles of twin-bore tunnel between Old Oak Common in west London and the railway’s terminus at Birmingham Curzon Street with an incredible 9.4 million tonnes of material excavated during their tunnel drives. The longest tunnel – under the Chilterns – stretches for 10 miles, while the Northolt tunnels run for 8.4 miles from West Ruislip to Old Oak Common in west London. Additionally, there is a short 1-mile twin bore tunnel beneath Long Itchington Wood in Warwickshire. A short section of mined tunnel is also being dug between the Victoria Road Crossover Box and Old Oak Common. Alongside these deep tunnels, HS2 is also delivering around 5 miles of shallow ‘cut-and-cover’ tunnels in rural areas such as Burton Green in Warwickshire, Chipping Warden in West Northamptonshire and Wendover in Buckinghamshire.

Two more TBMs are expected to launch next year to begin digging the tunnels from Old Oak Common to HS2’s final destination, London Euston.

For further information click here and  uk/65 for tunnelbuilder archive. Visit https://www.hs2.org.uk/. 42/25.