Dry ice pellet solution blasts slippery leaves off railway lines

In a new Network Rail-funded project, the researchers plan to install their leaf-busting technology underneath passenger services run by train operator Northern.

Developed by researchers from the University’s Department of Mechanical Engineering, the cleaning system fires dry ice pellets in a stream of air at supersonic speed at the railhead, which freezes any leaves on the line. The frozen leaves are then blasted away as the dry ice pellets turn back into a gas. 

Expected to be installed and ready for testing on the live rail network in 2023, it will enable passenger services to clean the track when needed, particularly in autumn and winter months when falling leaves form slippery layers and make it more difficult for trains to stop and start.

In 2021, Sheffield University worked with Northern to test the technology onboard an empty passenger train on the live rail network. The trials ran throughout autumn and winter 2021/2022 at speeds of up to 60mph and found that the dry ice system is more effective at removing leaves from the line, cleaning the track and reducing stopping distances, than methods currently used by the rail industry.