HS2 launches first TBM at site close to London

As part of the largest infrastructure project in the UK, HS2 Ltd will launch the 2,000 tonne tunnel boring machine (TBM) ‘Florence’ from the South Portal site next to the M25 motorway in Buckinghamshire.

 Florence, the first of 10 TMB hat will work on the UK’s HS2 high-speed rail network, being launched from the South Portal site next to the M25 motorway in Buckinghamshire

Florence, the first of 10 TMB hat will work on the UK’s HS2 high-speed rail network, being launched from the South Portal site next to the M25 motorway in Buckinghamshire

This is the launch of the first of 10 giant tunnelling machines that will dig 64 miles of tunnels between London and the West Midlands on a project that will transform transport links between Britain's major cities, freeing up space on the rail network for more freight and local services and support the UK's transition to net-zero carbon emissions.

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 and help to safeguard the woodland and wildlife habitats above ground. A second machine ‘Cecilia' will launch next month to excavate the second tunnel at the South Portal site.

HS2 Ltd chief executive Mark Thurston said: "The launch of our first tunnelling machine is a major moment of progress for the HS2 project as we work to deliver a high-speed railway that will offer low-carbon alternatives for long-distance journeys across the UK.

"With more than 16,000 jobs already supported by the project and thousands of companies big and small benefiting from contracts, HS2 is providing a major boost to the economy in these difficult times. The start of tunnelling is a moment of genuine excitement for everyone involved, and I hope the entire country will get behind this truly transformative project."

The first two TBMs 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.

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.

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 15m a day. Each tunnel will require 56,000 precision-engineered, 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, commented: "Align is very proud to be launching the first two TBM on the HS2 project. The TBM 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 TBM, 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."

Built by Herrenknecht, at its factory in south-west Germany, the two 170m long machines were transported to the UK in more than 300 separate shipments last year, before being reassembled, tested and commissioned by an expert team of tunnelling engineers at the Chiltern tunnel south portal site, near the M25 to the north-west of London.

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