posted on 11th Aug 2020 15:04
On 11 August 2020 HS2 revealed the first images and publicly-chosen names of the first two completed Tunnel Boring Machines (TBMs) that will excavate the twin-bore Chiltern tunnel on the first phase of the UK’s new high speed line between London and the West Midlands. The names - Florence and Cecilia - were suggested by students at Meadow High School in Hillingdon and The Chalfonts Community College, Buckinghamshire, inspired by female scientific and medical pioneers.
Around 4,500 people from across the UK took part in the poll to select the final names, with Florence taking 40 % of the vote and Cecilia a close second with 32 %. The schools that suggested the names are close to HS2’s South Portal site, from where the first tunnel boring machines will launch early next year. The first two TBMs will be operated by HS2’s main works contractor, Align JV - a joint venture formed of three international infrastructure companies: Bouygues Travaux Publics, Sir Robert McAlpine, and VolkerFitzpatrick.
The Herrenknecht-built 2,000 tonne machines will be shipped in pieces to the UK and arrive at Align's main site to the west of London just inside the M25 later this year. ‘Florence’ is set to be launched early next year to begin digging the 10-mile-long Chiltern tunnel. ‘Cecilia’ will launch around a month afterwards and dig the other half of the ‘twin bore’ tunnel.
Both 170 m long machines are specifically designed for the mix of chalk and flint they will encounter under the Chilterns. Operating a ‘continuous boring’ technique, they are expected to take around 3 years to excavate the 9.1 m diameter tunnels which will be lined with concrete as they go. The TBMs will mix the spoil with water to form a slurry which will be pumped back to the main site where it will be treated before being used for landscaping on-site, removing the need for additional HGVs on local roads.