The first completed tunnel boring project on the HS2 rail project has been confirmed, after workers broke through the final layer of rock in a mile-long section under the Warwickshire countryside.
HS2 announced on July 26th that the Long Itchington Tunnel excavation had been completed by workers using a boring machine called Dorthy, which was named after Dorothy Hodgkin, who in 1964 became the first woman to win the Novel Prize in chemistry.
The tunnel has been dug in order to protect the ancient woodland above it, a response to a key environmental concern expressed by many of those sceptical of or hostile to the HS2 project. Others will be cut to protect other scenic places like the Chilterns, or to avoid disrupting built-up urban areas such as west London, Crewe town centre and south Manchester.
As the tunnel was cut out, 790 concrete rings were put in place, but this number will be small in comparison with the figure for some of the larger tunnels that will be dug over the course of the project.
Indeed, there will need to be a lot of conveyor belt installation work to transport debris out of the tunnels during the process. Overall, 64 miles of tunnel will be built just between London and Crewe, with 130 million tonnes of earth excavated in the process.
A further release from HS2 has revealed images of one of these tunnels, below Euston Station in London. But this is just the start of the long stretch of tunnel under the capital. Further north will be the longest tunnel of all, measuring 16 miles as it passes under the Chilterns.
While most of these will be dug using huge boring machines, five will be ‘green tunnels’ created through the cut-and-cover method, which will then be covered over by turf and vegetation to reduce the environmental impact.
