By Lynda Myer
The third TBM in HS2 Ltd projects, which is TBM Emily and named after Emily Sophia Taylor who helped establish the Perivale Maternity Hospital in 1937 before becoming Ealing’s first female mayor in 1938, was launched by HS2’s London Tunnels contractor, Skanska Costain Strabag (SCS) joint venture; and it is due to dig almost half of the 13.5km Northolt Tunnel.
The drive path of this machine will be 5.5km beneath Ealing from Victoria Road Crossover Box, near HS2’s new Old Oak Common station, to Greenpark Way in Greenford.
With 1,700 tonnes weight and a 9.11m diameter cutterhead, this Herrenknecht EPBM has been designed for the soft London clay.
As HS2 client director Malcolm Codling stated, in order to starting up the TBM Emily,the preparation process had been complex but the project remained on schedule to complete the Northolt Tunnel in 2025.
Carrying HS2 trains in and out of London will be up to the Northolt Tunnel that is extending between the new Old Oak Common superhub and the outskirts of the capital at West Ruislip.
While this twin-bore tunnel is being built in two sections, already construction of its eastward between West Ruislip and Greenford is undergoing by two TBMs, named Sushila and Caroline; and TBMs Emily and Anne are being used to bore the tunnel in the opposite direction from Victoria Road Crossover Box to Greenford.
Considering that digging of 5.5km of the tunnel in total is up to Emily and Anne and is slightly less than those being used on the other section, the date of commissioning Emily was 25 February and Anne as the fourth and final Northolt TBM is slated to be launched next month.
Following that the TBMs will be extracted from the ground through shafts at Greenpark Way in 2025, they are all set to complete their journeys.
In order to removing the London clay extracted to build the tunnel from Victoria Road Crossover Box the conveyor will be used, and this amaount is going to be transported 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.
After the breakthrough on the Atlas Road Logistics Tunnel in January, HS2 is also making progress on preparations on the separate tunnel between Old Oak Common and Euston, that is the line’s ultimate central London terminus. The logistics tunnel runs from the Old Oak Common Station box to Atlas Road logistics site and will facilitate the tunneling operation to construct the Euston Tunnel.
Later this year two further TBMs are due to be delivered to Old Oak Common and will be stored in the underground box until the government gives the go-ahead for 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.
