Stainless Steel AVA Footbridge Set to Revolutionize UK Rail Accessibility and Sustainability

To address the challenges the UK’s ageing rail infrastructure poses, the AVA consortium has developed an innovative modular footbridge and lift system that promises to transform accessibility at small and medium-sized stations across the country.

The AVA (Adaptable, Versatile, Accessible) footbridge, made from stainless steel using state-of-the-art manufacturing techniques, is quicker to install, more cost-effective, and more sustainable than traditional footbridge designs.

The UK’s rail network, much of which dates back to the 19th century, presents various challenges for engineers tasked with maintaining and upgrading the infrastructure to meet modern standards. One pressing issue is the lack of accessible footbridges at many smaller stations, making travel difficult or impossible for passengers with reduced mobility. Network Rail, the infrastructure owner, has been seeking solutions to this problem that can be deployed quickly and efficiently across the network.

The AVA footbridge represents a fundamental rethink of how railway footbridges are designed and constructed. Unlike traditional bespoke designs that require extensive on-site fabrication, the AVA bridge is based on a modular system that can be largely pre-assembled off-site.

The bridge’s structural elements are made from laser-cut and CNC-formed stainless steel plates bolted to create standard 1.2-meter modules. These modules can then be combined to create a bridge of the required length, up to a maximum span of 20 meters. The modular design allows the bridge to be easily adapted to the specific requirements of each station, with minimal modification required.

The use of stainless steel offers several critical advantages over traditional materials. The grade of steel used, Forta LDX 2101, is highly corrosion-resistant and has a design life of 120 years, far longer than painted carbon steel. This durability means the bridge will require minimal maintenance over its lifetime, reducing costs and disruption.

One of the most significant benefits of the AVA footbridge is its speed of installation. Traditional footbridge projects can take up to a year to complete, causing prolonged rail services and passenger disruption. In contrast, an AVA bridge can be installed in weeks, thanks to the extensive use of off-site fabrication.

The bridge modules, complete with cladding, glazing, and internal services, are delivered to the site ready for assembly. The supporting foundations can be prepared in advance without disrupting rail traffic, and the bridge itself can be assembled during a single 36-hour possession of the tracks (a period when trains are not running). This represents a significant reduction in on-site time compared to traditional builds.

Alongside the bridge itself, the AVA system includes a new lift design that offers improved reliability and ease of maintenance. Developed by SCX, a specialist in motion control systems, the lift features innovations such as a dual-drive system for redundancy and a more robust door mechanism.

The lift is designed as a series of modules that can be pre-assembled and thoroughly tested off-site before being delivered to the station for installation. This plug-and-play approach reduces the time required for on-site commissioning and helps to ensure reliability from day one.

The bridge and lift create a step-free route across the railway, greatly enhancing accessibility for passengers with reduced mobility, prams, or heavy luggage. The bridge’s open design, with glazed sides and integrated lighting, also helps to create a sense of space and security for all users.

The use of stainless steel not only extends the structure’s design life but also reduces the embodied carbon compared to a conventional painted steel bridge. The modular design and bolted connections mean that the bridge can be disassembled and moved to a new location if required, while the stainless steel components can be easily recycled at the end of the bridge’s life. This approach aligns with Network Rail’s ambitions to reduce the carbon footprint of its infrastructure.

Over the 120-year design life of the AVA bridge, the reduced maintenance requirements are expected to deliver significant savings in whole-life costs compared to traditional designs. Using standardized components and manufacturing processes also offers the potential for economies of scale as the design is rolled out across the network.

The AVA footbridge is the result of a collaboration between the AVA consortium members, including Network Rail, design consultants Expedition Engineering and Hawkins\Brown, construction contractor Walker Construction, and specialist manufacturers Xtreme Systems and SCX. The prototype bridge was funded by Network Rail and Innovate UK as part of the TIES Living Lab program, which aims to accelerate innovation in the transport infrastructure sector.

Following successful prototype testing, the first production AVA bridge will be installed at Stowmarket station in Suffolk in 2025. Network Rail is considering a batch procurement approach for future AVA bridges, which could enable further cost savings and shorter lead times.

The AVA team is also continuing to refine and optimize the bridge design based on the lessons learned from the prototype. Future iterations could incorporate new materials and manufacturing technologies to reduce costs and environmental impact further.

The AVA footbridge should help improve the design, manufacturing, and installation of railway footbridges in future. By using the latest in design and manufacturing technology, the system promises to deliver a step-change in station accessibility while also reducing costs, environmental impact, and disruption to passengers