Sui Generis International provide bespoke FRP components for first-in-the-UK railway footbridge solution on behalf of Network Rail

Network Rail have led a new innovative project to develop and deliver the UK’s first fully modular, FRP (Fibre Reinforced Polymer) footbridge.

The new footbridge was officially opened in January 2023 and the location of the prototype was decided on Wistantow, north of Craven Arms in Shropshire. The footbridge replaces an extremely high-risk level crossing that closed a number of years ago after it was deemed unsafe for use.

The project was driven by Network Rail Wales and Borders Programme Manager, Andy Cross, who secured early development of the prototype and funding for the bridge. Andy advocated for the FRP bridge for over 10 years, and his original concept for the crossing has ultimately become what is now known as the FLOW bridge.

 

Faster, more sustainable and affordable option

Designed and funded by Network Rail’s Research and Development (R&D) team, the bridge aims to provide a faster, more sustainable, and affordable option to dangerous rural railway crossings across the UK. These crossings are shown to pose a significant public risk, spanning across over three tracks with obstructed visibility.

Turning the traditional methods on their head, the vision for the FLOW bridge was modernised by using a modular system made from FRP composites, a polymer matrix (typically a resin) reinforced with fibres made of glass, carbon, or aramid.

The modular system offers the benefit of adapting the footbridge to specific site requirements using a wide variety of possible configurations, rather than standardising a one-fits-all solution which cannot take all environmental factors into account, causing building and site delays.

The modularised system also allows for most of the materials to be manufactured off-site, reducing the pressure on installation teams and disruption of passenger services and track closures. Installation of the footbridge can be done in half the amount of time it would take for a traditional in-situ produced steel structure.

 

FRP has significant advantages over traditional building materials

The composite structure also gives the project significant advantages over traditional building materials such as steel or concrete. In comparison to steel, composites are highly cost effective, up to 70% lighter than steel and have a high strength-to-weight ratio. This considerably reduces transportation and installation costs, making FRP an ideal solution for the footbridge.

Composites also offer new opportunities for designs that would be hard to achieve with traditional materials. In this instance, the lightweight structure of the FLOW bridge allowed for the use of hand-driven ('RapidRoot') foundations in place of concrete. This new type of foundation further reduces costs and contributes to the reduction of carbon emissions.

Overall, the use of composite materials contributed to an estimated cost reduction of 40% over that of a traditional made footbridge. Additionally, by eliminating the use of concrete and lowering the overall weight, the carbon footprint was also improved from 102 tonnes CO2e to 98 tonnes.

With bridge monitoring technology installed, Network Rail will be able to track the performance and usage of the footbridge in efforts to drive further improvements and provide efficient maintenance. Certainly, one of the top features of the bridge is that if at any stage the bridge is found to no longer be required, the modules can easily be dismantled and moved to a new location.

 

Sui Generis involvement

Sui Generis, known for their bespoke GRP capabilities, first got involved with the project after Project Manager, Eddie Blacket of Foflo reached out to Managing Director, James Luckham, and invited him to express an interest in the project. Eddie had previously seen and appreciated a set of GeoMet furniture at a flower show and had retained the company’s details.

Following a comprehensive tender process, Sui Generis were invited to join the project team which comprised of 9 UK based SMEs (Small Medium Enterprises) with little to no experience with bridges or the rail industry.

With a rough concept in mind and specific deliverables, Programme Manager, Andy Cross tasked his new project team with refining the design in real terms. The team collaboratively embarked on a research & development (R&D) centred design-environment to create the innovative bridge prototype.

Following the design and development stage, Sui Generis were selected to manufacture and supply the main bridge structure, including the modules that form the bridge walkways, the stair inlays, and sidings. This meant very close collaboration with KS Composite, the company responsible for the delivery of spine. The moulded components and deck units from Sui Generis were carefully designed to clamp to the spine to create the smooth flowing form. Within just 11 months, the team went from concept to building the prototype.

The project was also complimented by the inclusion of the Safe Tread non-slip flooring and stair tread product range, a key product within the Sui Generis portfolio. Glass Reinforced Polymer (GRP or fibreglass) non-slip floor sheets and anti-slip stair treads were installed across the entirety of the bridge structure to ensure the longevity of the footbridge and to improve all-weather public safety.

 

Looking Ahead

From the beginning of the tender process, this project required a significant level of resource commitment from the business. While a long and challenging undertaking, it has been a welcome opportunity for the team which has seen the business take a bold step into experiential engineering solutions, supported by the highly skilled operatives and managers within the business who provide decades of experience.

To undertake the project, the business has taken a strategic view of operations to maximise capacity and balance the additional pressure on resource by implementing extensive planning across its product portfolio. With the potential for further work within the rail industry, the business is anticipating some key investments into its operations and resources to continue to pursue projects within the bespoke fabrication space.

Managing Director, James Luckham shared his view of the experience, saying “Building a full scale FRP bridge isn’t something we get asked to do every day and it has been a privilege to work alongside Network Rail and other expert SME businesses. Sui Generis has played a major role in consulting, designing, manufacturing, delivering, and installing this incredible piece of architecture. The result is a testament to our exceptionally skilled workforce, and we are proud to be part of bringing safe, sustainable solutions to landscapes and communities.”

 

Serving the Local Community

The launch of the FLOW bridge prototype has understandably gained a lot of attention and interest, both from within the rail industry and from various industries across the world who can see the benefits of incorporating composite solutions into their projects as an alternative to traditional building materials.

The Network Rail Research and Development team have expressed intention that the FLOW bridge prototype will be developed into the rural networking solution for high-risk rail crossings or pedestrian walkways across the country

Network Rail Wales and Borders Programme Manager, Andy Cross said: “The flow bridge was designed, first and foremost, as a safety solution but our teams have also gone above and beyond to create a quicker and more sustainable option for the future of the railway.

“Its versatile design means we have already started looking at fully accessible versions, with lifts and ramps, for other locations where that would be a suitable option.”

With the success of the prototype, there has been a high demand expressed for these types of rural footbridges, with over 500+ potential sites already being identified.

With two new sites being green lit for development, the team are hoping to continue to develop the FLOW bridge through the learnings of the prototype bridge in Wistantow.

The Sui Generis team have been engaged to continue their work with the project team to research and develop the next iteration of the bridge, coined as ‘FLOW Bridge 2.0’. The next design phase will focus on the same fundamental key enablers and deliverables but will look to develop the bridge even further. Current design updates include improving the speed of installation through enhancements which offer a more ‘plug-and-play’ approach, improving stair access points for engineers and the addition of ramp accessibility.

 

 

 

Related articles

Going with the FLOW: Innovative ‘first-of-its-kind' railway footbridge opens to the public replacing dangerous level crossing - Network Rail

Flow - An innovate approach to composite bridges - Flowbridge

Innovative Flow footbridge - Network Rail

 

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