New tread could extend the service life of rails
Trafikverket, the Swedish Transport Administration, is the first authority in the world to test a new innovation for track maintenance on operational tracks.
The concept is based on the idea of replacing only the outer surface of the rail instead of the entire rail. The method is both economical and climate-smart.
The product is called Rerail, and has been developed together with Luleå Railway Research Centre and Luleå University of Technology. The idea is simple. The tread is that part of the rail which is subject to wear caused by the wheels of trains. When the surface is worn out, the tread itself is replaced by a steel band. At present, entire rails have to be prized up and replaced by new ones.
– The product can save time and money in that it prolongs the service life of the rails and reduces the need for maintenance. It also has a positive impact on the environment because it is unnecessary to replace the entire rail. And the fewer the number of rails that are manufactured, the lower the emissions of carbon dioxide. Manufacturing a ton of railway rails generates carbon dioxide emissions of one ton, says Matthias Asplund, track specialist at Trafikverket.
The testing carried out by Trafikverket is conducted on a track at Luleå Rail Yard. An 8m-long rail is provided with a new tread in the form of a steel flange and is then welded in place. The test track is only used by goods trains. At the same time, rail traffic is sufficiently heavy for Trafikverket to be able to analyse the extent of degrading. The test is measured and continuously monitored.
The test shall indicate what kind of resistance the new surface has against fatigue, wear, deformation and corrugation. Furthermore, it is important for Rerail to have the right conduction capacity because the rails are used for returning the current that drives the locomotives.
The testing begins in June and continues for three years. After this, the test pieces will be dismantled and analysed.
Only after this will Trafikverket decide on whether or not the product can be used.
About Rerail
- The steel is tempered and extremely resistant against wear. The same material is used for armoured plating and as wearing plates in construction plant, but also in cars in order to protect passengers against injury in connection with crashes.
- It is possible to save large quantities of rails, since the method means that only 12 per cent of the rails are replaced instead of 100 per cent.
- The need for track grinding decreases since the material in Rerail does not display the same surface cracks (headchecks) during loading and is at the same time subject to less wear than today's rails.