Engineers working on HS2’s London tunnels have begun the complex process of lifting the last of four giant tunnelling machines (TBMs) to the surface. The first section of the machine, named ‘Anne,’ including its 9.11-metre diameter cutterhead, was lifted out of a shaft at Green Park Way in Greenford, west London, over the bank holiday weekend.
The massive TBM weighs 1,700 tonnes and is 150 metres long. It will be dismantled and lifted out of the shaft in sections using a large gantry crane. Anne is one of four TBMs that have successfully completed the excavation of the 8.4-mile-long Northolt tunnels, which run between West Ruislip and the new station at Old Oak Common.
The four TBMs launched from West Ruislip and Old Oak Common and met in the middle, excavating more than 4 million tonnes of London Clay and installing nearly 100,000 concrete segments to form the tunnel walls.
The TBM ‘Anne’ is named after Lady Anne Byron, a 19th-century educational reformer and philanthropist. She established England’s first co-operative school in 1834, which provided education for working-class children in west London.
