On 13/05/2021 HS2 Ltd launched the 2,000 t TBM Florence from HS2’s South Portal site next to the M25 in Buckinghamshire. It’s the first of 10 TBMs that will collectively dig 103 km (64 miles) of tunnels between London and the West Midlands. The new high-speed railway will offer low-carbon alternatives for long distance journeys across the UK.
The 170m-long TBM will dig the first of a pair of 16 km (10 miles) long tunnels under the Chiltern hills, operating 24/7 for the next three years . Cecilia, the second TBM will be launched next month to excavate the second tunnel at the South Portal site.
The first two TBMs - designed specifically by Herrenknecht for the mix of chalk and flints under the Chilterns - will be operated by HS2’s main works contractor, Align – a joint venture formed of three international infrastructure companies: Bouygues Travaux Publics, Sir Robert McAlpine, and VolkerFitzpatrick.
Each machine operates as a self-contained underground factory - digging the tunnel, lining it with concrete wall segments and grouting them into place at a speed of around 15 m a day. Each tunnel will require 56,000 fibre-reinforced segments – which will all be made on site.
Chalk excavated from the tunnels will be used for landscaping at the south portal site once construction is complete, creating wildlife-rich chalk grassland habitats across 127 hectares of the southern Chiltern hills.
The names of the two TBMs were suggested by students at Meadow High School in Hillingdon and The Chalfonts Community College, Buckinghamshire, which are close to the tunnel launch site. They were inspired by Florence Nightingale, the founder of modern medicine, and pioneering astronomer and astrophysicist, Cecilia Payne-Gaposchkin. 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%.
For further information on the project please click here and uk/65 for the tunnelbuilder archive and visit https://www.hs2.org.uk/. 20/21.
