Third giant tunnelling machine launched on HS2

Press release 26/02/2024 11:26 CET

TBM Emily, launched by our Skanska Costain STRABAG (SCS) JV, to construct Northolt Tunnel under the capital.

Front shield of TBM Emily lifted at Victoria Road Crossover box site_cropped

Progress on HS2’s London tunnels programme has pushed forward as the third tunnel boring machine (TBM) constructing the Northolt Tunnel was launched on Friday. 

TBM Emily, named after Emily Sophia Taylor who helped establish the Perivale Maternity Hospital in 1937 before becoming Ealing’s first female mayor in 1938, will bore 3.4miles under Ealing from Victoria Road Crossover Box to Greenpark Way in Greenford.

The 8.4mile tunnel is already under construction, with TBM Sushila currently boring the downline tunnel, which Emily will complete, from West Ruislip. Once both TBMs finish their journeys, they will be extracted from the ground through giant shafts at Greenpark Way. When HS2 is in operation, the tunnel will take HS2 passengers from the Old Oak Common super-hub station to the outer edge of London.

Our Skanska Costain STRABAG joint venture team assembled the TBM underground at the Victoria Road site after being lifted in parts and lowered into a shaft.

Manufactured by world-leading tunnelling experts, Herrenknecht in Germany, TBM Emily weighs 1,700 tonnes and has a 9.11m diameter cutterhead. The TBM is an earth pressure balance machine, which is designed specifically for the soft London clay that will be extracted from the ground.

A second TBM, named Anne, will launch next month, constructing 3.4miles of the upline tunnel, completing the twin bored Northolt Tunnel. The quartet of TBMs are all set to complete their journeys in 2025.

The London Clay, that will be extracted to build the tunnel, will be taken away from Victoria Road Crossover Box by conveyor, and taken to the London Logistics Hub at Willesden Euro Terminal. From there, it will be taken by rail and reused at sites in Cambridgeshire, Kent and Rugby.

James Richardson, Managing Director of Skanska Costain STRABAG joint venture (SCS JV), said: “The SCS JV London Tunnels team are well on the way to delivering a new railway into the heart of London with the launch of TBM Emily today. Next month we will be launching TBM Anne, who together with Emily will form the tunnel from Old Oak Common to Greenpark Way Shaft, where they will meet with TBMs Sushila and Caroline, who are already halfway to completing their journeys from West Ruislip.”

The team are also making progress on preparations to tunnel to Euston, with the Atlas Road Logistics Tunnel breakthrough in January. The logistics tunnel is runs from the Old Oak Common Station box to Atlas Road logistics site and will facilitate the tunnelling operation to construct the Euston Tunnel.

Malcolm Codling, project Client Director, HS2 Ltd, said: “We are working at peak construction on HS2, delivering the tunnels which HS2 trains will travel through under London. The preparation to launch TBM Emily has been complex and we remain on schedule to complete the Northolt Tunnel in 2025.”

Two further TBMs will be delivered to Old Oak Common later this year, and placed into the underground box, ready to begin boring the Euston Tunnel. Following the Government’s Network North announcement in October last year, the funding and delivery arrangements for the Euston Tunnel are being reviewed.