HS2’s contractor delivering the London tunnels, Skanska-Costain-STRABAG Joint Venture (SCS JV), has signed the first of two contracts for the production of concrete precast tunnel segments that will be used to construct HS2’s London tunnels. Pacadar UK will be manufacturing the tunnel lining at their factory in the Isle of Grain, Kent. It will be the largest contract the company has ever delivered in the UK.
The segments will be used in the first TBM drives in London, when two machines will be launched in early 2022. The production will begin in January next year at the factory and the materials will then be delivered to HS2’s TBM launch site in West Ruislip by rail, reducing HGV movements on the road, where the construction of the twin bored, 8km long, Northolt Tunnel West will begin.
Malcolm Codling, Project Client for HS2 Ltd, said, “We are making exciting progress across London and are gearing up to start our immense tunnelling work underneath the capital. It is great that the first of our precast tunnel segments are being manufactured here in the UK, providing UK jobs at a time when it is most critical as the country recovers from the pandemic.”
Over 160,000m3 of concrete will be used to make the segments which form a 9.5m outside diameter tunnel 0.35m thick. Each complete ring is made of seven segments and a key. Each segment weighs approximately seven tonnes. They will be used by the first two of six 2,600 tonnes TBMs that are currently under construction by Herrenknecht, in Germany. They will operate for 22 months non-stop, except for Christmas Day and other bank holidays. The first TBM for the London tunnels will be delivered later this year and will be assembled for launch in 2022.
James Richardson, Managing Director of Skanska-Costain-STRABAG joint venture (SCS JV) said, “This is an important milestone in the programme as we get closer to launching our first two TBMs next year. We’re building 41.6km of twin bore tunnels, covering the 21km distance between West Ruislip and Euston, tunnelling up to 50m below ground. Using rail to deliver all our segments required for our tunnelling programme will help us to remove one million lorry journeys from the road over the lifecycle of our programme.”
The construction of the first tunnel will be completed in 2024.