Skanska Costain Strabag joint venture (SCS JV) has launched an 847-tonne tunnel boring machine (TBM) from its Atlas Road site in North Acton, from where it will build an 853-metre tunnel to the Old Oak Common station site.
But this tunnel will not be used by HS2 trains. Instead it will be used to deliver materials and remove spoil from the northern portal where HS2’s Euston twin bored tunnel will be constructed, getting trucks off the roads.
This tunnel drive should be completed in around six months, with the tunnel constructed from 4,264 concrete segments forming 533 tunnel rings. The segments, each weighing more than three tonnes, have been cast by Pacadar in Kent.
When complete, the logistics tunnel will be used to transport 8,010 tunnel segment rings to construct the main HS2 Euston tunnel. These segment rings are being cast by Strabag in Hartlepool and will never be transported by public road – using only the rail network and the logistics tunnel.
The logistics tunnel will also have a conveyor system that connects to an existing conveyor at Atlas Road, taking the London clay being excavated to construct the Euston tunnel to the HS2 London logistics hub at Willesden Euro Terminal. From there, the spoil will be taken by train for re-use at sites in Kent, Cambridgeshire and Rugby.
Malcolm Codling, HS2’s project client for the London tunnels, said: “The Atlas Road logistics tunnel is key to how we will be constructing the Euston tunnel between Old Oak Common and HS2’s Euston station. The logistics tunnel allows us to take 70,000 lorry journeys off the local roads that would otherwise have been required and will reduce the impact of HS2’s construction on the local community.”
The TBM being used to construct the tunnel has been repurposed using components from TBM Ellie that was previously used on the Crossrail project. Ellie dug two sections of the Crossrail tunnels in the capital – from Limmo Peninsula in Canning Town to Royal Victoria Dock, and between Pudding Mill Lane and Stepney Green – boring a total of 2.23 miles.
Its manufacturer, Herrenknecht, has remanufactured components including the shield and the cutting wheel specifically for HS2’s requirements. Following the transition, Ellie has been renamed Lydia, after a local primary school teacher.
SCS JV managing director James Richardson said: ”This is our third TBM to launch in London and later this year we will have five machines operating. Four of these will be boring the HS2 tunnels, linking West Ruislip and Old Common. Today’s launch is significant as it is not used for the operational railways, but will create a direct link to between our logistics hub and Old Oak Common, allowing us to transport tunnel segments and spoil without using local roads.”
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