HS2’s first two giant Tunnel Boring Machines, named Florence and Cecilia, have arrived in the UK. Work on the project’s first tunnels, which are being constructed by our Align joint venture, starts early next year. The two enormous 2,000 tonne machines will now be meticulously reassembled, tested and commissioned by an expert team of tunnelling engineers, before they start work on the project’s first tunnels, which are being constructed by our Align joint venture.
The 10-mile-long ‘twin bore’ Chiltern tunnel will be the longest on the project, with the TBMs set to be underground, working 24/7 for more than three years.
Designed specifically for the mix of chalk and flints under the Chilterns, the two identical TBMs will dig separate tunnels for north and southbound trains, with Florence set to launch first and Cecilia to follow a few weeks behind.
Each machine operates as a self-contained underground factory, which as well as digging the tunnel, will also line it with concrete wall segments and grout them into place as it moves forward at a speed of 15 meters a day.
Each tunnel will require 56,000 segments, which will all be made on site. A crew of 17 people will operate each TBM, working in shifts to keep the machines running around the clock. They will be supported by more than 100 people on the surface, managing the logistics and maintaining the smooth progress of the tunnelling operation.
Built by Herrenknecht at its factory in Germany, the two 170m long machines were transported to the UK in more than 300 separate shipments over the course of two months, with the parts now safely delivered to the Align Chiltern tunnel site, to the west of London just inside the M25.