HS2 buys an ex-Crossrail tunnelling machine for Old Oak Common …

A tunnel boring machine that was used to dig part of the Elizabeth line is now being used to build a logistics tunnel for HS2[1] in west London.

The construction site at Old Oak Common[2] is spread over several locations and to avoid road trips between them, HS2 is digging a huge logistics tunnel underneath Willesden Junction to link them up. And to dig that tunnel, they’ve got hold of an old Crossrail TBM to do the job.

Atlas Road logistics tunnel map – from HS2 presentation

The TBM has been repurposed using components from the machine used by Crossrail to dig tunnels from Limmo Peninsula in Canning Town to Royal Victoria Dock, and between Pudding Mill Lane and Stepney Green.

That TBM was called Ellie.

After she finished with Crossrail, the components were sent back to the manufacturer, Herrenknecht in Germany, where it was refurbished for the slightly different soil conditions in west London, and will now be used to dig an 853-metre tunnel linking the Old Oak Common station building site with a large site at Atlas Road.

The refurbished TBM has been renamed, this time Lydia, after Lydia Gandaa, a former teacher at nearby Old Oak Common Primary School and a founding member of the Bubble & Squeak social enterprise in the area.

Assembly of HS2 TBM ‘Lydia’ at Atlas Road (c) HS2

The tunnel is needed because the Atlas Road site[3] is the holding centre for deliveries to the HS2 construction site, and also to remove spoil from the area via the railway that runs right past it.

However, the Atlas Road site isn’t next to the Old Oak Common station, and as the tunnel boring machines will launch from the station, they need to get the huge tunnel rings that will be used in the tunnel from Atlas Road to Old Oak Common.

Hence a third tunnel — to link the two sites.

It’s an indication of how large the HS2 tunnels and trains will be, that a tunnel boring machine used to dig the impressive Elizabeth line tunnels[4], is a mere logistics tunnel for HS2’s needs. The main railway tunnels being built for HS2 are a quarter bigger than the Elizabeth line tunnels.

Engineers assemble HS2 TBM ‘Lydia’ at Atlas Road (c) HS2

Once it has been completed, this logistics tunnel will be used to transport over 8,000 larger tunnel segment rings to construct HS2’s Euston railway tunnel. The segment rings are being manufactured in Hartlepool and will be sent to London via the West Coast Mainline, and once delivered at the Atlas Road site they will be sent down the logistics tunnel to the HS2 tunnels being constructed to link Old Oak Common to Euston.

A conveyor system will also run through the logistics tunnel, and will connect to an existing conveyor at Atlas Road, taking the London clay being excavated to construct the Euston Tunnel to HS2 London Logistics Hub at Willesden Euro Terminal. From there, the spoil will be taken by train for use in landscaping sites in Kent, Cambridgeshire and Rugby.

Now that construction of the logistics tunnel has started, it will be completed in around six months, with the tunnel ring segments, each weighing over 3 tonnes, being supplied by Pacadar on the Isle of Grain in Kent.

Tunnel segment rings for the logistics tunnel (c) HS2

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.”

Interestingly, thanks to the route the logistics tunnel has to take, it will pass right underneath the Elizabeth line depot at Old Oak Common — which seems quite apt as it’s an ex-Crossrail machine digging the tunnel.

References

  1. ^ HS2 (www.ianvisits.co.uk)
  2. ^ Old Oak Common (www.ianvisits.co.uk)
  3. ^ Atlas Road site (www.ianvisits.co.uk)
  4. ^ Elizabeth line tunnels (www.ianvisits.co.uk)