HS2 Viaducts: Low-Carbon Innovation

The HS2 project, a major high-speed rail initiative in the UK, is pioneering new methods for creating low-carbon infrastructure. Building on lessons learned from European high-speed rail projects, the HS2 team has implemented a more efficient design for viaducts, resulting in significant reductions in carbon emissions.

Following the early success of HS2’s first double composite viaduct at Wendover Dean, this innovative design has been rolled out to four more viaducts across Buckinghamshire, Oxfordshire, and West Northamptonshire. The double composite approach involves adding a concrete bottom to the usual steel beam and reinforced concrete deck structure, forming a hollow box-like structure. This design significantly enhances efficiency, reducing the overall thickness of both concrete and steel.

The benefits are substantial. By optimising the structure in this way, the amount of embedded carbon in these viaducts has been cut by between 52% and 66%. This not only supports the UK’s environmental goals but also sets a new standard for sustainable infrastructure projects.

The design and construction of these viaducts have been a collaborative effort. HS2’s main works contractor, EKFB (a joint venture of Eiffage, Kier, Ferrovial Construction, and BAM Nuttall), worked closely with design partners ASC (comprising Arcadis, Setec, and COWI) and architects Moxon to bring these innovative structures to life.

This project exemplifies how the construction industry can embrace sustainability without compromising on functionality or safety. The success of these low-carbon viaducts demonstrates the potential for similar approaches to be adopted in future infrastructure projects, both within the UK and internationally.