High Speed 2 contractor Skanska Costain STRABAG Joint Venture has awarded the first of two contracts for production of precast concrete tunnel sections for the London tunnels to Pacadar UK.
The company will produce the tunnel lining at its Isle of Grain factory and be shipped from there to HS2’s West Ruislip site, from where a pair of Tunnel Boring Machines (TBMs) will be launched in early 2022. This is where the twin-bore, five-mile-long Northolt Tunnel West will start from.
More than 160,000 cubic meters of concrete will be used to make the segments, which will form a 9.5 metre external diameter tunnel with the lining 35cm thick. Each ring will be made of seven segments each weighing about seven tonnes.
The TBMs are being built by Herrenknecht, Germany, and will operate non-stop for 22 months, except for Christmas Day and other bank holidays. The first is due to be delivered later this year and assembled for launch in 2022.
Total length of the tunnel bores from West Ruislip to London will be 26 miles, the same length as those bored for Crossrail. The first tunnel is due for completion in 2024.