Research Finds Discarded Tyres Can Make Train Tracks More Durable And Cut Maintenance Costs

Hyderabad: Train tracks go through a lot, posing an engineering challenge in the form of high cost of maintenance. However, new research addresses the problem while also countering another persistent issue—the tyre waste. Researchers showcased a world-first system of rubber shock absorbers made from recycled tyres and their effectiveness in protecting railway tracks from damage.

They installed track sections with the rubber underlay to monitor vibration, track settlement, and ballast degradation under real-world conditions. Compared to the conventional track sections, it showed significantly less degradation and greater stability.

The recycled rubber grids on a stretch of test track laid at Chullora NSW (Photo: Ecoflex via University of Technology Sydney)

Published in the Canadian Geotechnical Journal, the research paper “Effects of Rubber-Intermixed Ballast on Train Loading Response Through Field Monitoring in Western Sydney” details the technology validated over a two-year period by a collaborative team from the University of Technology Sydney (UTS), Sydney Trains, Transport for NSW, and industry partners EcoFlex and Bridgestone—following extensive monitoring at a live Sydney Trains freight line in Chullora, New South Wales, Australia.

The patented technology utilises a strategically arranged layout of tyre cells, constructed from recycled tyres and infilled with waste materials such as spent ballast and coal wash. Additionally, recycled rubber grids, cast from worn-out conveyor belts sourced from mining sites, are placed directly beneath the primary load-bearing layer of the rail track, known as ballast.

A stretch of test track was laid at Chullora NSW (Photo: Ecoflex via University of Technology Sydney)

UTS researcher Buddhima Indraratna, the original inventor of this technique and Director of the UTS Transport Research Centre, explained that the rubber-based underlay serves to protect the ballast, preventing it from being pulverised and thereby extending the lifespan of the entire track structure.

"Additionally, the underlay controls the way the train load is distributed to the deeper, softer and often wet soil beneath the track, preventing unacceptable soil settlement and weakening of the overlying track," he said. "This translates directly to lower maintenance costs, fewer track closures for the public, and improved network reliability."

In addition to saving the rail industry millions of dollars annually by reducing the demand for freshly quarried rock for ballast, it could also provide a solution for end-of-life tyres, which Australia alone generates in millions a year.

Going forward, the research team will test the technology in more demanding locations, such as at bridge approaches and junctions, where abrupt changes in track stiffness create high-impact zones prone to rapid degradation.