SIDELINES
Compiled by Graeme Pickering
Three quarters of tunnel excavated
TUNNEL boring machines (TBMs) Florence and Cecilia are beyond three-quarters of the way through creating the twin bores of the 10-mile tunnel that will take the HS2 route under the Chiltern hills.
The TBMs reached the vent shaft near Little Missenden in Buckinghamshire during early August. Launched in summer 2021, they have already extracted around two million cubic metres of chalk and flint.