The first Tunnel Boring Machine (TBM) was launched by HS2 yesterday and it’s named as Florence. This 2,000-ton TBM will work on over a £100m project from the Chilterns tunnel south portal site which is located next to the M25 in Hertfordshire.
This is the first of 10 TBMs that will dig 64 miles of tunnels between London and Birmingham. Florence and Cecilia were named after nurse Florence Nightingale and astrophysicist Cecilia Payne-Gaposchkin respectively.
Both the TBMs will each dig a bore of the 10-mile Chilterns tunnel. Cecilia will launch next month to excavate the second tunnel at the south portal site. The TBMs are designed specifically for the mix of chalk and flints under the Chilterns, and built by Herrenknecht in Germany.
Each TBM operates as a self-contained underground factory, digging the tunnel, lining it with fibre-reinforced concrete wall segments and grouting them into place at a speed of around 15 metres a day. Each tunnel will require 56,000 segments, which will all be made on site.
A crew of 17 people on board will operate each TBM, working in shifts to keep the machines running 24/7. More than 100 people on the surface will support by managing the logistics and maintaining the smooth progress of the tunnelling operation.
After the completion of construction, chalk excavated from the tunnels will be used for landscaping at the south portal site. Florence and Cecilia are operated by HS2’s main works contractor for the central section ‘Align.’
Align is a joint venture of Sir Robert McAlpine, Bouygues Travaux Publics, and VolkerFitzpatrick. Besides, it is notable that Florence and Cecilia are the most advanced TBMs ever used in the UK.