The first huge 2,000 tonne tunnelling machine passed the one mile mark last week on the HS2 , the new Britain’s high speed rail link construction between London, Birmingham and the north. The 170m long Tunnel Boring Machine (TBM) was launched in May and has covered the first mile cutting in a mix of flint and chalk beneath the Chiltern hills outskirts London. The TBM was named ‘Florence’ by the local school children, after Florence Nightingale, the founder of modern nursing, who lived for long in Claydon, Buckinghamshire. It is one of two identical machines digging the two ten-mile-long tunnels. The other machine is called ‘Cecilia’ and is a short way behind. The TBMs are expected to break out Britain’s high speed rail tunnel like three years’ time.
Made specifically for Chiltern’s geology, the machines have self-contained underground factory, excavating, lining a concrete wall segments on the tunnel and grouting them into place while moving forward. Operation of the first two TBMs is done by HS2’s main works contractor, Align. Align is a Bouygues Travaux Publics, Sir Robert McAlpine, and VolkerFitzpatrick joint venture. Seventeen crew who work in shift keep the machines running and are supported by over 100 workers on the surface, who manage the logistics and the smooth progress of the tunnelling.
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The scope.
The separate northbound and southbound tunnels will each require 56,000 precision engineered, fibre-reinforced concrete wall segments segments. The segments are being made at the tunnel’s south portal, next to the M25. On the first mile, Florence and her crew have installed over 5,500 separate segments, weighing around 8.5 tonnes each. Materials of around 2.7 million cubic metres excavated during the construction of the tunnels will be used for landscaping at the south portal site. Upon completion, it will help create wildlife-rich chalk grassland habitats of around 90 hectares.
There will be ten TBMs in total on the HS2 Britain’s high speed rail which will be creating a 64 miles tunnel from London to the West Midlands with major tunnels while approaching London and Birmingham. The scheme is supporting over 20,000 jobs and more than 650 apprenticeships and is set to change transport links between Britain’s major cities, freeing up space on the rail network for additional freight and local services. HS2 Will also support transition to net zero carbon emissions in the country.
