On 18 December, Florence, Align’s first TBM, reached the half-way point (8km) on its drive north under the Chiltern hills. With Cecilia, its second TBM, reached the half-way point in early January, this is a fantastic achievement for all those involved, especially when you consider that the Chilterns tunnel at 16km, is by far the longest tunnel on HS2 Phase One. 

By reaching the half-way point, in total approximately 1.4 million cubic metres of spoil has been excavated from both tunnels and processed by the Align slurry treatment plant, with the resulting chalk cake landscaped in Pynesfield Quarry, a dedicated area on Align’s South Portal site. Combined within both tunnels, 56,000 segments forming 8,000 rings have been installed.

On 16 December, our teams reached another milestone: the Align cross-passage and shaft teams came together to celebrate the first breakthrough via an adit at their shaft at Chalfont St Peter.

Congratulations to our teams, along with its supply chain partners for these accident-free performances.