News on HS2 in Hillingdon

Our first two Tunnel Boring Machines (TBMs) have arrived in the UK ahead of their launch early next year. The two 170m-long TBMs are the largest ever used on a UK rail project and will start to be assembled on site this week, ready to begin digging the 10-mile-long Chiltern tunnels.

TBM Florence during manufacture

The two enormous 2,000 tonne machines, named Florence and Cecilia, will now be reassembled, tested and commissioned at the on site by an expert team of tunnelling engineers, before they start work on the high speed rail project’s first tunnels. Built by Herrenknecht, a world leader in TBM manufacturing, at its factory in south-west Germany, the two machines were transported to the UK in more than 300 separate shipments over the course of two months.

Sections of the TBMs ready for assembly on site

The ‘twin bore’ Chiltern tunnel will be the longest on the project and the first to start construction, with the TBMs working underground 24/7 for more than three years. Designed specifically for the mix of chalk and flints under the Chilterns, the two identical TBMs will dig separate tunnels for north and southbound trains, with Florence set to launch first and Cecilia to follow a few weeks behind.

Each machine operates as a self-contained underground factory, which as well as digging the tunnel, will also line it with concrete wall segments and grout them into place as it moves forward at a speed of 15 metres a day. Each tunnel requires 56,000 segments which will all be made on site. A crew of 17 people will operate each TBM, working in shifts to keep the machines running 24/7. They will be supported by over 100 people on the surface, managing logistics and maintaining the smooth progress of the tunnelling operation.

The TBM seals at the South Portal

These first TBMs will be operated by our main works contractor, Align – a joint venture of three international infrastructure companies: Bouygues Travaux Publics, Sir Robert McAlpine, and VolkerFitzpatrick. Align expects to recruit 1,200 vacancies, with over 100 opportunities for apprentices. Recruitment and investment will be targeted at upskilling unemployed local people, particularly women, under 25s and those with disabilities.

The TBM names 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%.

If you have a question about HS2 or our works, please contact our HS2 Helpdesk team on 08081 434 434 or email hs2enquiries@hs2.org.uk .