Recycled rubber and plastic on track for innovative railway sleepers
An EU-funded project is helping to green the railway sector and promote the circular economy by using sleepers made from recycled plastic and old tyres, which can also incorporate solar panels and smart technology.
© Greenrail Group SRL, 2017
Railway sleepers across the world are commonly made of concrete. However, the EU-funded GREENRAIL project has come up with a novel, green idea for sleeper materials that will help the EU rail sector boost its environmental and circular economy credentials, as well as improving rail sleeper technology.
Every day, 4.8 million tonnes of waste the equivalent to 478 Eiffel Towers is produced in urban zones around the world at a rate that is growing faster than urbanisation itself. The World Bank estimates that the global daily production of city waste will rise by 71 % by 2025. GREENRAIL hopes its innovative idea will contribute to reducing urban waste by becoming part of the circular economy.
The sleepers being developed by GREENRAIL are made from a blend of rubber from old vehicle tyres that have reached the end of their lives and recycled plastic from urban waste. The sleepers can be designed to meet the technical requirements of any railway track worldwide.
For more than 50 years, concrete railway sleepers have been the standard, despite their many disadvantages including a relatively short lifespan and high levels of noise vibrations. Our project will ring the changes for the sector and help tackle the growing problem of urban waste, says project coordinator Maura Saltimbanco, head of EU projects at the Greenrail company in Italy.
The GREENRAIL sleeper has an inner core of pre-stressed concrete a compressed form of ultra-strong concrete often used in construction and an outer shell made of a mix of rubber from old tyres and recycled plastics. The pioneering sleeper requires up to 35 tonnes of recycled urban waste per kilometre of railway track.
Moreover, rubber and plastic materials increase the average lifespan of a railway sleeper by reducing its maintenance needs and costs by two to two and a half times compared to concrete. The outer shell creates less noise and fewer vibrations as the train passes over it, reducing noise pollution for nearby residents. Another advantage of the projects technology is its greater resistance to fracturing problems caused by freezing and thawing.
GREENRAIL is following the principles of a circular economy using waste as a resource by giving used rubber and plastic a second life. However, the project team is aiming higher by incorporating smart technology into the outer shell of the sleeper. The shell has been developed to include green technologies such as photovoltaic solar panels that could provide electricity to railway lines and smart communication systems.
GREENRAIL sleepers will renovate railway infrastructure by making it more innovative, energy efficient and sustainable, while also making a significant contribution to environmental issues, says Saltimbanco.
In December 2017, Greenrail sealed its first licensing agreement with a US-based company to commercialise and produce its sleepers. The company is also in talks with several public and private entities in Europe, the Middle East and Central Asia. The sleeper has been patented in 80 countries worldwide and was demonstrated at the EXPO 2017 in Astana, Kazakhstan.
GREENRAIL is now working on further research into the inbuilt smart technologies.