The TBMs are being built by world-leading manufacturer Herrenknecht and will be delivered to site by the end of 2021.
They are being designed and manufactured specifically for the London clay and chalk ground conditions they will bore through.
The London HS2 tunnels are twin bored, and will be 13 miles each way, and with a combined total of 26 miles, equivalent to the Crossrail drive.
Once assembled, they will begin the tunnel drive from mid-2022, until completion at the beginning of 2024.
SCS JV has the tunnelling job between central London and the M25.
Overall there will be 10 TBMs purchased to construct the 64 miles of tunnelling along the phase one route between the West Midlands and London.
The London tunnels will begin just outside of Euston station and will be below ground until they emerge in West London at Old Oak Common station.
The route will continue underground from Old Oak Common to the outskirts of West London.
Key facts
- TBMs will run for 22 months non-stop except for Christmas day and bank holidays
- Each machine will be 140m in length
- The cutter head will be 9.84m in diameter, slightly smaller than the machines boring through the Chilterns
- They each weigh 2,050 tonnes, roughly the weight of 20 blue whales
- 1.2m cubic metres of excavated material will be removed, weighing 2.46m tonnes
Malcolm Codling, Client Director at HS2, said: “The procurement of these incredible machines is an exciting step towards the construction of the London tunnels.”
These first two London TBMs will be launched from a portal at West Ruislip and will travel 5 miles east, creating the western section of the Northolt Tunnel.
Once they arrive at Green Park Way in Greenford the machines will be extracted from the ground and the site will then be used as a vent shaft.
The 8.4 mile tunnel will be completed with a 3.4 mile tunnel drive from Old Oak Common using two further TBMs which are yet to be procured.
A second tunnel between Euston and Old Oak Common will complete the remaining 4.5 miles of London tunnel between the two HS2 stations.
James Richardson, Managing Director of Skanska Costain Strabag joint venture, said: “This partnership with Herrenknecht has brought together leading expertise in both our organisations and together we are constructing some of the most advanced TBMs in the world to efficiently drive the tunnels under London.”
Earlier this year, HS2 revealed images of two TBMs that have been made to construct the tunnels through the Chilterns.
The names of the machines were suggested by local schoolchildren and subject to a public vote with Florence and Cecilia being the chosen names. The process for naming the first two London tunnelling machined will be revealed in due course.
