‘Hedgehog’ sleepers last longer than concrete with less carbon

Network Rail’s Wales and Western region has developed a new type of sleeper that has far less embedded carbon than existing types and is expected to have double the service life.

The region worked with Network Rail’s Technical Authority, responsible for safety and engineering, to create the ‘hedgehog’ sleepers – so nicknamed because the ends look like hedgehogs nesting under the rail.

The polymer sleepers contain 90 per cent less embedded carbon than wooden models and 78 per cent less than those made from concrete.

Research has found that sleepers account for 30 per cent of the carbon embedded within railway infrastructure, so Network Rail looked for technology to reduce the carbon emissions generated by manufacturing them and to make sleepers more resilient to climate change.

NR developed the new design with Lankhorst Engineered Products, a Dutch firm that already offers a range of hybrid polymer railway sleepers. The hedgehog sleepers are made up of 90 per cent recycled materials and are themselves fully recyclable.

As well as reducing carbon emissions, the new composite design means that hedgehog sleepers will last at least twice as long as their concrete counterparts, reducing the need to close parts of the railway to install replacements as they near the end of their working life. The sleepers can also be laid mechanically, which will make replacement quicker and easier.

Nick Matthews, Network Rail’s programme engineering manager, said: “I’m delighted that we’ve been able to work with Lankhorst Engineered Products to develop a new type of sleeper technology that will reduce the carbon impact of the railway quite significantly.

“We demonstrated the hedgehog sleeper at this year’s Rail Live event in June in the Network Rail village and the attendees were as excited as we are about a new product with excellent practical value as well as environmental benefits.”

Aran van Belkom, Lankhorst Engineered technical director, added: “This project is a good fit with our purpose: think limitless, act sustainable for future generations. We appreciate Network Rail’s engagement to set a new industrial standard.”