Network Rail has developed a striking and innovative footbridge that has the potential to improve safety, drastically cut construction costs and transform rail crossings.
The curved, modular ’flow’ bridge, made of lightweight Fibre-Reinforced Polymer (FRP), has been named to reflect its modern, flowing design.
Flow footbridge side view
A Network Rail-led project, the bridge has been delivered and developed by in-house teams. Including from the Research and Development Portfolio and Network Rail Design Delivery. As well as the Wales and Western region.
Over just 11 months, we’ve worked with small and medium-sized businesses to design and manufacture a prototype. The bridge will cost considerably less than traditional steel structures to produce and install. No concrete has been used in the structure or its foundations. And it’s less than half the weight of a traditional footbridge.
The new-look bridge will initially be used to replace high-risk rural footpath crossings. This will form part of our ongoing drive to make the railway safer and easier for pedestrians to cross.
The adaptable, modular design means it is well suited to a variety of locations. And its low cost will enable us to also replace existing bridges which might otherwise be temporarily fixed or refurbished.
The 21m long bridge has an in-built monitoring system to record how it performs and is used. This allows future improvements to the design and more efficient maintenance.
Flow footbridge steps close up
The prototype has been trial built at a test centre in Long Marston, Warwickshire. It’s on show there at the 2021 RAIL Live event on Wednesday 16 June and Thursday 17 June, 2021.
Work is planned to develop a ramped version of the bridge. And we’ll listen to the views of stakeholders and the community as we continue to work on the design.
Flow footbridge construction time-lapse video
The time-lapse video shows construction of the prototype Flow footbridge over five weeks at a test track in Warwickshire. The team took necessary precautions to keep each other safe and prevent the spread of Covid-19 by working within current Government guidelines.
Why Flow?
The name reflects the bridge’s curved, open design and sums up its attributes:
F – Fibre Reinforced Polymer, incorporating natural and sustainable materials.
L – Lower cost and lighter weight, in comparison to traditional steel bridges.
O – Optimised design to incorporate both architectural forms and functional needs to maximise operational use.
W – ‘Working’ bridge with monitoring bult in to support asset management.
More information about the footbridge’s development
Demand for a new style of footbridge has been underpinned by two key factors; the drive to improve safety at level crossings and the need to find an alternative to the standard, heavy steel footbridge commonly used on the railway.
In 2010, we embarked on a landmark level crossing risk reduction programme. Its objective is to close and upgrade crossings across the network, which will improve safety for everyone and reduce risk.
Around 2,250 of our 6,000 level crossings are footpaths over the railway. They are a challenge to manage; open to misuse; and pose a safety risk to pedestrians, cyclists and horse riders.
Most of these crossings rely on users to stop, look and listen out for trains. Around 60 percent have insufficient sighting and are equipped with whistle boards, which direct drivers to sound the horn so that pedestrians know a train is coming. A much smaller percentage are protected by miniature stop lights and audible warning devices.
Even those crossings with protection are still at risk from incidents and accidents. The safest solution is to replace footpath crossings with footbridges.
When considering building a new footbridge or replacing an old one, Network Rail currently has just one option; the standard non-station footbridge design that is heavy, unattractive and expensive to deliver.
This project challenged us to find a way to deliver a modern footbridge that is not only cheaper but also quicker to produce that would be suitable for a number of locations.
We face a number of challenges when building or replacing footbridges on the rail network, including:
Objections to the appearance of heavy, steel footbridges by communities and stakeholders.
The average cost of a standard footbridge can be more than £1m.
The time taken to install a standard footbridge, which often requires a closure of the railway.
Based on the benefits and the potential cost savings, £1.5m of Network Rail Research & Development funding was secured to develop new designs.
A collaborative and innovative approach was used to deliver the project, allowing it to progress from concept to trial build in just 11 months.
A design contest was launched to encourage small and medium-sized businesses and alternative suppliers to put forward their ideas. The scope was flexible, allowing for innovation in the design and development.
A design contest was launched to encourage small and medium-sized businesses and alternative suppliers to put forward their ideas. The scope was flexible, allowing for innovation in the design and development.
The footbridge is made from Fibre-Reinforced Polymer (FRP) – a lightweight material that is widely used in other industries, including the manufacture of aircraft and cars. The material is very strong but lightweight, leading to lower transport and installation costs.
The footbridge has been designed to be flexible to build and can be customised to suit different needs and locations. It has two key elements – a load-bearing structural spine, and deck units that clamp onto the spine with a common design for the stairs and span.
The stairs and floor panels are inserted into the deck – as are the parapets, or sides, of the bridge, allowing different materials and styles to be used. There is potential to offer some level of customisation to suit the needs of the community.
The parapets for the prototype are made from toughened laminated glass, showcasing what is possible with the design. The materials create a very open feel for users of the bridge, making the railway a positive part of the journey.
FRP is a combination of strong fibres set in resin; effectively like a man-made wood. This bridge mainly uses glass fibres, with carbon fibres for high-stress components. Natural ‘flax’ fibres have also been tested to explore future low carbon sustainable materials.
The new footbridge has a wide range of benefits, including:
Reduced time and cost to produce and install. The aim is to install it in days rather than weeks for traditional bridges with much shorter lead-in times.
An opportunity to improve safety by replacing foot crossings over the network.
An alternative to replace rather than repair existing bridges or foot crossings
Modern, flowing and open design that is adaptable and modular to suit different rural locations.
Reduces the environmental impact of a new bridge, with the use of natural composite fibre in the materials and reduced impact from the installation on the surrounding land.
Exciting and novel design which encourages public support for installation in local communities.
Built-in monitoring to assess usage and maintenance needs.
This project has taken a different approach to working, with Network Rail taking the lead for design and construction. This has allowed us to work with a number of small and medium-sized businesses, many of whom haven’t worked on railway projects before but have the skills and expertise to bring the concept of a lightweight, low-cost footbridge to life. They are:
Foflo – who have provided virtual working platforms and new approaches to team working and monitoring the risks and opportunities of the project.
Knight Architects – specialist bridge architects who were able to come up with an exciting new concept that the team could turn into reality.
Jacobs – who provided design expertise and independent checking of the Network Rail design.
KS Composite – a UK-based manufacturer whose usual clients include F1 teams and prestige car manufacturers. They manufactured the bridge spine.
Sui Generis – another UK based manufacturer who specialise in moulded components, including tractor bodywork. The made the deck units that clamp to the spine.
Epsilon Optics – UK specialists in fibre-optic monitoring, who designed, manufactured and installed the monitoring system.
Q-Railings – a UK-based glazing company, who usually install structural glazing and parapets to buildings.
JT Consulting – who designed, manufactured and installed the Rapid Root foundation system.
For more information or to get in touch with us, please contact us by visiting our contact us page or by calling our 24-hour national helpline on 03457 11 41 41.