A giant cantilever structure has been used to build the first section of HS2’s 472 m River Tame West viaducts.
This method will be used to build nine viaducts in HS2’s Delta Junction in the West Midlands, totalling 6,500 m in length.
The River Tame West viaducts carry three rail tracks with one single-track viaduct and one double-track viaduct. The process installs pre-cast concrete segments produced at HS2’s nearby factory, with the construction of the 20 piers to support the viaducts starting in 2023 and the first spans of the three-track section completed this Spring.
The first process saw the two segments placed onto two 42 m truss beams, moved into place using a skidding trolley and then secured by post-tensioning techniques.
A 22 m mast which includes a temporary post-tensioning cable stays and a 14 m swivel crane was used to build the giant cantilever structure.
The crane lifts and installs one concrete segment into place at a time. The permanent post-tensioning tendons are then strained to allow the removal of the temporary cable stays, leaving the permanent structure firmly in place.
2,500 concrete segments will be moved into place using this method and all deck segments are set to be in place by August 2026. Balfour Beatty Vinci (BBV) is HS2’s main works contractor for the West Midlands, constructing 90 km of HS2 in the region.
