HS2 has announced that its tunnel boring machines (TBMs), Florence and Cecilia have reached the Little Missenden ventilation shaft on their journey to dig HS2’s longest tunnels.
Since their launch in 2021, the 2,000-tonne machines have been excavating twin tunnels between the M25 and South Heath in Buckinghamshire. During their journey, the machines are digging the tunnels, lining them with concrete segments and grouting them into place.
They have now reached a 35-metre deep shaft near Little Missenden, which will provide ventilation and emergency access to the tunnels. With this achievement, Florence and Cecilia are now 75% of the way through boring the 10-mile Chiltern tunnel.
The two TBMs are operated by Align, which is a joint venture formed of Bouygues Travaux Publics, Sir Robert McAlpine and VolkerFitzpatrick.
“HS2 will transform rail journeys between London the midlands and the north, and free up space on the existing network for more freight and local services. We’re seeing great progress on the tunnel, which will take our trains deep under the Chiltern hills, safeguard the woodlands and wildlife habits above and significantly reduce disruption to communities.”
Currently, HS2 has five TBMs in the ground, with a further five due to be launched in the future.
In total, they will create 64 miles of tunnel between London and the West Midlands, including major tunnels on the approach to London and Birmingham.
