A kit of parts for the two enormous 2,000 tonne machines – named Florence and Cecilia – has been set out for assembly at contractor Align joint venture’s Chiltern tunnels site.

The parts will now be meticulously reassembled, tested and commissioned, by an expert team of tunnelling engineers, before they start work on the project early next year.

The 10-mile-long twin-bore Chiltern tunnel will be the longest on the project and the first to start construction. Both TBMs will be operated 24/7 by a crew of 17 people for more than three years moving at 15m a day.

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.

Preparations are well advanced at the Chiltern Tunnels portals

Each tunnel will require 56,000 segments, all to 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 the logistics and maintaining the smooth progress of the tunnelling operation.

Align Project Director Daniel Altier: “Now that the parts have arrived the detailed job of assembling and commissioning the machines has begun.

“There are also considerable other activities continuing on our site to prepare for the launch of Florence and Cecilia next year. This includes the construction of a factory that will manufacture the concrete segments to be used to line the tunnel and a slurry treatment plant that will process material from the tunnels.”

The Align Joint Venture expects to recruit for 1,200 vacancies, with over 100 opportunities for apprentices.

They plan to target their recruitment and investment in upskilling local people who are currently unemployed, with a particular focus on women, under 25s and those with disabilities.