News on HS2 in Bucks & Oxfordshire

World-leading onboard robot technology is being harnessed to improve safety and efficiency on our first two giant tunnelling machines, set to launch early next year.

The 'Krokodyl' robot, pioneered by main works contractor, Align, is the first of its kind in the world and will be installed in the two tunnel boring machines (TBMs) used to bore the 16km-long Chiltern tunnels. Similar to robotic arms used on car factory production lines, Krokodyl will perform simple repetitive tasks, removing wooden spacers between tunnel segments and inserting connection dowels – something people would normally do.

As the TBM moves forward, tunnel segments are erected to form a structural watertight ring designed to support the ground loads. Each segment weighs up to eight tonnes and is delivered to the TBM with wooden spacers between them, generally removed by hand. By fully automating this process, the Krokodyl removes the need for people to work in this potentially hazardous area and helps with the installation of the 112,000 tunnel segments. A second feature of the robot, known as the Dobydo, then places the dowels into position ready for the segment to be slotted into place. Automating this process also reduces risk to people and improves safety and efficiency.

The Krokodyl in action

Both 170m-long machines are specifically designed for the mix of chalk and flint they will encounter under the Chilterns. Operating a pioneering ‘continuous boring’ technique, they are expected to take around three years to excavate the 9.1m diameter tunnels which will be lined with a concrete ring made of seven separate segments as they go. They will convert the spoil into slurry which will then be treated before being used for landscaping on-site, removing the need for additional HGVs on local roads.

The 'Florence' TBM

If you have a question about HS2 or our works, please contact our HS2 Helpdesk team on 08081 434 434 or email hs2enquiries@hs2.org.uk .