High-tech safety boost for train axles A set of new instruments promises to help assess cracks and corrosion in train axles, streamlining maintenance and upgrading safety. This promises to enhance train operation and bring benefits to rail users. Industrial Technologies © Thinkstock Europe's rail infrastructure for passengers and cargo is growing considerably, demanding increased reliability and safety in rail vehicles and equipment. Train axles in particular are prone to damage from constant cracking and corrosion that increases with distance travelled. The EU-funded project 'Whole life rail axle assessment and improvement' (WOLAXIM) worked on upgrading the efficiency of axles by extending their shelf life and improving inspection technologies. The project developed three promising methods to detect cracks and evaluate corrosion. The first involves a portable microscope and software tools to pinpoint corrosion more efficiently and improve decision making on scrapping axles. The second method involves shortening overnight inspection of hollow axles for high-speed trains from 20 minutes to 5 minutes, while the third verifies axle strength as wagons pass through the station. The project designed and tested an instrument that detects cracks 2–3 mm deep on the axles of trains passing through inspection stations at 5–10 km/h. It also built an instrument to assess corrosion damage, including risk of fatigue crack growth within an area of 10 cm2 over a 10-second measurement period. The third instrument that was produced inspected hollow axles using a non-rotating probe and could detect cracks up to 3 mm deep within 5 minutes. Lastly, the project team developed software to help calculate inspection intervals for crack growth caused by corrosion fatigue, providing yet another analysis tool for axle life estimation. With the European Commission considering rail as the greenest transport mode and working towards its propagation, the project results could help enhance safety and efficiency significantly. This is especially important since there are currently around 250 000 passenger carriages and over 1.2 million freight wagons in circulation with a total of 3.5 million axles. The project will particularly help small- and medium-sized enterprises in the sector to build on these results and cater to this enormous market. This will bring benefits not only to the transport sector but to the economy as well, while underlining rail as a safer, greener and leaner transport mode.
