March 2024

HS2's Tunnelling Boring Machine Completes 10-Mile Journey

Rendel’s HS2 team were on site to celebrate Friday’s breakthrough by TBM Cecilia, following a 10-mile journey beneath the Chiltern Hills, nearly three years since its commencement. This breakthrough signifies the completion of the primary excavation work on the 16 km twin-bore tunnel, the longest on the 190 km route.

Cecilia's arrival occurred just weeks after the first machine, TBM Florence, broke through the tunnel on February 27th. Together, Cecilia and Florence have established a 10-mile twin-bore tunnel network spanning from Rickmansworth, Hertfordshire, to Wendover, Buckinghamshire. These tunnels are poised to serve as critical passages for HS2 trains commuting between London and Birmingham.

Rendel Limited and Ingerop, as part of the Align JV consortium, have played instrumental roles in advancing the Chiltern Tunnel project since 2016, delivering a range of services.

Our dedicated team of engineers had the privilege of witnessing the historic moment as TBM Cecilia joined forces with Florence, marking the culmination of years of hard work and dedication.