The announcement of Network Rail’s partnership with the National Composites Centre (NCC) to develop the Futura composite bridge comes at a time where the industry as a whole is keyed in on driving sustainability and delivering social value. Can lessons be applied from other mobility sectors? And what are the real benefits at the passenger level? Tangent sits down with Ian Grimes, senior asset engineer, Network Rail, to find out more
The intriguing partnership of Network Rail and the National Composites Centre (NCC) to develop the composite ‘Futura’ footbridge could be the beginning of leaving a low-carbon legacy for station infrastructure, in the eyes of senior asset engineer, Ian Grimes.
“These [footbridges] can be the first major intervention that some of the local stations in particular are seeing in 100/150 years,” explained Ian. “There’s an unintended consequence if we get that wrong. It might not enhance the community, and we want to lift things up and think about our longer-term legacy.”
The partnership with the NCC, seeing Network Rail join as a Tier One member, will seek to develop the concept footbridge, designed by Marks Barfield Architects & COWI, into a full prototype, to highlight the benefits of using Fibre-Reinforced Polymer (FRP) as a sustainable composite material in new build and replacement structures in rail station environments.
Aside from the sustainability benefits for future builds – previous footbridge builds predominantly used steel– Ian noted how using composite materials for the footbridges could lead to a quicker installation and the prototype can apply learnings from other transport projects.
We want to lift things up and think about our longer-term legacy
“We’ve always struggled with standardisation, because of every site of footbridge installation is slightly different,” Ian said. “The span might be a bit longer, or the steps need to be higher – but what we’re looking at with the NCC is using the same technology they use in aviation, like the wings on different planes being slightly longer or shorter to suit the size of the main body.
“But aviation doesn’t just re-do everything all of the time: they create a template mould that’s set up and can be adjusted. We think we can take that technology, and use it for things like we’ve said: the spans, or the height in the stair flights.” Using modern methods of construction in taking concepts from wet trades such as plastering and brick-laying, the composite bridge can be built off-site in five distinct parts, bolted together in kit form, and constructed entirely in the confines of safer factory conditions.
“At the moment, in a traditional build, [construction times] could be anywhere between six and nine months, sometimes even longer, if we need possessions of the track and we can’t get that,” Ian outlined. “We think if we can do the ground-work and the enabling works on this, which again links to modern methods of construction, we can do this overnight.”
Sustainability as a driver
The greatest benefit of the composite bridge prototype will be the long-term learnings that can be applied to the circular economy and reducing waste material in construction, Ian says. “What we’re doing with FRP is exploring the circularity of it all in terms of the circular economy.” Ian went on to note how a footbridge at a station could last 100 years, but if that station closes in 30, what happens to the footbridge?
“We’re talking to the wind energy sector, for example,” Ian commented. “There’s tons and tons of wind turbines now, coming to the end of their first design life. They’re designed for 20 years, so how do you take a wind turbine, and turn that into a bridge? They use similar materials.”
But now, the conversations are turning. You can almost see progress daily about it being value, rather than cost
Bringing in the benefits of composite in other industries is part of the wider sustainability drive from the sector, which Ian notes is “front-and-centre” with stakeholders like HS2 and the Environment Agency. Ian added that pushing innovations like the composite bridge in rail will help drive construction towards the UK Government’s Construction 2025 sustainability goals.
“In Network Rail we’ve just become the client lead on I3P Zero Carbon World. [Sustainability] is front-and-centre now. I think we’re starting to see the pace now where in the next four or five years, we’ll mainly be talking about carbon. Previously we were getting into things such as option engineering, and cost-value engineering – it was all about cost.
“But now, the conversations are turning. You can almost see progress daily about it being value, rather than cost.”
“The essence of the bridge project is to stop the bridge being a bridge, if that makes sense. It’s to turn the bridge into a product,” Ian said. In reviewing the project, Ian and the Buildings and Architecture teams he is part of at Network Rail will be placing a particular focus on the traceability of the supply chain of materials in a bid to improve safety and standardisation in the composite project.
“If you think back to the Grenfell Fire disaster, and investigations and legal cases are still ongoing, but in the materials process, something was being built, handed back, and being managed, and there was no line of sight between whether what was specified, what was built, and what’s being looked after.”
For this project, safety is the goal: how the composites react in fire and to inclement weather? What is the long-term durability of the materials used? And, continuing to look forward, how can sustainability stay front-and-centre? Ian says these will be the questions asked for the viability of using the bridges in future constructions in stations across the UK.
Holistically, Ian says, the bridge needs to deliver social value: “The old types of footbridges weren’t the best lookers,” he noted. “These [bridges] can be the first major intervention that some local stations in particular are seeing in 100/150 years.
“We’ll know success within three years as a project. But, longer term, in 30 or 40 years, what will people say, looking back? There’s a real test there, on what we’ll do to the built environment.”