On Sunday, 25th May, engineers working on the HS2 project successfully lifted the 9.48-metre diameter cutterhead, front, and middle shield of Tunnel Boring Machine (TBM) Caroline. Weighing an impressive 850 tonnes, the components were hoisted using a massive gantry crane in a significant engineering feat.
This operation marks the end of TBM Caroline’s 5-mile journey from West Ruislip, which concluded in April when the machine arrived at an underground reception chamber. Over the course of its drive, Caroline excavated more than 1.2 million tonnes of earth and installed 4,217 concrete tunnel rings.
Named by a local school in honour of astronomer Caroline Herschel, TBM Caroline was one of four machines constructing the 8.4-mile Northolt Tunnel. This tunnel will eventually carry HS2 trains from Old Oak Common Station to the outskirts of London. The first TBM to complete its section of the tunnel, Sushila, was removed from the Green Park Way site in March.
This milestone highlights the continued progress of HS2’s tunnelling operations and the remarkable engineering behind one of the UK’s largest infrastructure projects.
Image credits: HS2
