HS2, the UK's high-speed railway project, has reached a crucial stage as its Tunnel Boring Machines (TBMs), 'Florence' and 'Cecilia', have advanced 90% through the 10-mile-long Chiltern tunnel. This marks a significant step in constructing HS2's longest tunnel, with a breakthrough expected early next year.
The two colossal machines, each weighing 2,000 tonnes and 170 meters long, will be launched near the M25 in the summer of 2021. So far they have excavated around 2.8 million cubic meters of chalk and flint, lining the tunnel with concrete segments as they progress.
"With our first TBM Florence having reached our fifth shaft at Chesham Road and our second TBM Cecilia due to reach the shaft shortly, this a great achievement for not only the tunnelling team, but also the supporting teams on the surface at the South Portal, manufacturing the concrete segments required to line the tunnels and processing the spoil from the tunnels,” said Didier Jacques, Align’s Underground Construction Director.
The project also focuses on environmental protection. Excavated material from the tunnels will be used to create around 90 hectares of chalk grassland habitat, which is vital for nature conservation.
As HS2 progresses, other tunnelling work is underway in London and Birmingham, with further developments expected next year. The breakthrough of the Chiltern Tunnel symbolizes not only engineering excellence but also HS2's commitment to sustainable development and the improvement of the UK's rail network.