Final breakthrough for HS2’s longest tunnel

The second tunnel boring machine (TBM) digging the future HS2 railway tunnels under the Chilterns has finished its job – meaning the two 10-mile tunnels have been completed and are now ready for fitting out.
Cecilia TBM breakbrough (c) HS2
Named Cecilia, the TBM has driven for 10 miles underground from just inside the M25 motorway to a site near the Buckinghamshire town of Wendover, and is the second TBM to complete the tunning work.
Between them, the two 2,000 tonne machines have built th