HS2 has released the first picture of one the two TBMs that will spend around three years digging the longest and deepest HS2 tunnels – from just inside the M25 to South Heath in Buckinghamshire.
The TBMs are 170m in length and weighs roughly 2000 tonnes. The size of the TBM cutterhead, which is still to be added will be 10.26 metres diameter.
Behind the cutterhead, the long tail of the TBM will be installing the concrete tunnel lining rings, made up of segments weighing an average 8.5 tonnes each. 112,000 of these concrete segments will be required to complete both tunnels.
The machines are being built by Herrenknecht in Germany, the same company that made the Crossrail tunnel boring machines.After completion the first two machines will be disassembled before beginning their journey to Britain. Once they have arrived on site, each TBM will be reassembled, ready for launch and to begin their life underground.