HS2 launches first of 10 TBMs

The 170m-long ‘Florence’ TBM

HS2 has lunched the first of 10 giant tunnel boring machines (TBM) that will dig 64 miles of tunnel on phase one of the new high-speed railway.

The first 170m-long TBM, named Florence, is the largest ever used on a UK rail project. It will dig 10 miles of tunnel under the Chilterns, operating 24/7 for the next three years

Named after nursing pioneer Florence Nightingale – a name suggested by local children due to her residence at nearby Claydon House in Bucks, and chosen in a public vote – the TBM will dig the first of a pair of 10 mile long tunnels under the Chiltern Hills.

A second machine ‘Cecilia’ will launch next month to excavate the second tunnel at the South Portal site.

The first two TBMs, built by German firm Herrenknecht, 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 will dig the tunnel, lining it with concrete wall segments and grouting them into place at a speed of around 15 meters a day. Each tunnel will require 56,000 fibre-reinforced 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 the logistics and maintaining the smooth progress of the tunnelling operation.

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.

Align project director, Daniel Altier, said: “Align is very proud to be launching the first two TBMs on the HS2 project. The TBMs include a number of innovations to improve efficiency and the safety of the environment in which the crew will be working, that have never before been introduced on any previous TBMs, worldwide.

“I would like to thank everyone in our integrated project team that includes Align, our design partner Align D and HS2, working closely with our suppliers, for all their hard work that has enabled us to get to where we are today, culminating in the launch of Florence.”

Story for CM? Get in touch via email: [email protected]


  1. HS2 reassurances of reinstatement of habitat are disingenuous.
    You can’t just replant ancient woodland and hedgerows or replace mature chalk meadows. The entire infrastructure of flora, fauna and fungi and how they integrate in ancient land cannot simply be replicated – it is going to simply be lost. And this isn’t just some esoteric concern of nature lovers and Countryfile – it will have an impact on the ecosystem of agriculture and essential wildlife for generations to come.

Leave a comment

Your email address will not be published. Required fields are marked *

Latest articles in News