A landmark development in engineering has seen the first UK use of a specialist cantilever process for HS2.
- The 472-metre-long viaduct in the West Midlands is being constructed using innovative techniques.
- Segments are secured by steel cables, showcasing advanced post-tensioning technology.
- This construction method is used globally and is making its debut in the UK through the HS2 project.
- Completion of the first spans marks a significant milestone in the development.
In a groundbreaking move, the UK has witnessed the debut of a specialist cantilever process employed in the construction of the 472-metre-long viaduct for HS2, illustrating a significant milestone in engineering. This innovative technique involves the use of steel cables to secure segments in place, a method pioneered by Campenon Bernard and now being utilised by Balfour Beatty Vinci for the River Tame West Viaducts.
The viaducts, located near Water Orton in north Warwickshire, represent an essential component of the HS2 infrastructure. With a design that comprises a single-track and a double-track viaduct, the River Tame West Viaducts play a crucial role in connecting London, Birmingham, and the north by crossing existing rail lines and waterways.
Construction on the 20 piers began in 2023, with substantial progress marked by the completion of the first spans in spring 2024. The process entails the meticulous placement of segments onto truss beams, which are then manoeuvred into position using a skidding trolley. This sophisticated technique highlights a forward-thinking approach to infrastructure challenges.
The innovative strategy employs a giant 22-metre-high cantilever mast and a swivel crane, pivotal in placing each concrete segment with precision. The permanent post-tensioning tendons are stressed progressively, allowing for the removal of temporary supports, thus securing each 45-metre span robustly.
This method, despite being a recent introduction to the UK, has been applied extensively on global projects, demonstrating its efficacy in overcoming complex engineering hurdles such as those posed by existing watercourses and existing utilities.
The operation, currently engaging a team of 40 professionals, aims for the completion of all deck segments by August 2026. Designed components prepared at HS2’s bespoke factory underscore the intricate planning and execution required, with 2,742 segments being manufactured for the broader development encompassing Delta Junction.
Nicolas Gallone, the Vinci director of works, emphasised the unprecedented nature of this technology in the UK, noting its importance for Balfour Beatty Vinci and the broader construction industry. “We’re using a specialist construction method to build the River Tame West Viaducts – a technique that has never been used in the UK before. It’s a significant moment,” he stated.
Sam Hinkley, HS2’s senior project manager, highlighted the success rooted in collaboration and innovation, marking this engineering feat as a proud moment for all involved. Such statements reflect the intensive collaborative efforts between designers, contractors, and the supply chain in driving forward this remarkable UK-first initiative.
The post-tensioning technology marks a transformative step in UK construction, heralding a new era of engineering capabilities.
