Contracts signed for HS2’s first giant tunnelling machines

Press release 15/10/2020 10:57 CET

Two 140-metre-long tunnel boring machines for the HS2 project are set to arrive on the Skanska Costain STRABAG joint venture (JV) site next year.

The London tunnels for HS2 are twin bored and will be 13 miles each way.


Contracts have been signed for HS2’s first two giant tunnelling machines, which will be arriving on our JV site late next year.

The tunnel boring machines (TBMs) are being built by world leading manufacturer Herrenknecht. They are being designed and manufactured specifically to deal with the London clay and chalk ground conditions they will bore through. Each will weigh approximately 2,050 tonnes, roughly the weight of 20 blue whales, with the cutter head measuring 9.84 metres in diameter. Once built, both machines will be transported by sea before being delivered to site at the end of 2021.

The London tunnels for HS2 are twin bored and will be 13 miles each way and, with a combined total of 26 miles, the London tunnels will be the same length as Crossrail. This programme of tunnelling between central London and the M25 will be undertaken by the Skanska Costain STRABAG JV. Overall there will be 10 TBMs purchased to construct the 64-miles of tunnelling along the HS2 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.

James Richardson, Managing Director for the Skanska Costain STRABAG joint venture, said: “As the construction partner responsible for the majority of tunnels on the HS2 project, our contract for the first two TBMs is a major milestone for us. 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.

“Work is already well underway to prepare for the first tunnel launch in 2022. Throughout these and all our activities, we are committed to involving local communities and stakeholders and supporting social development and employment through the 4,500 jobs that will be created.”

Malcolm Codling, Client Director at HS2 Ltd, said: “Building HS2 will showcase Britain’s world class capabilities in tunnelling. The procurement of these incredible machines is an exciting step towards the construction of the London tunnels, which will involve them working 24 hours a day, seven days a week.”

When assembled, the TBMs will begin the tunnel drive from mid-2022, until completion at the beginning of 2024. They will be launched from a portal at West Ruislip and will travel five 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 tunnels between the two HS2 stations.