Staff Research by Jurjen Hendriks
02/01/2014 - ongoing
autumn leaves, friction measurements, lrc, railtribometer,
NS, ProRail, University of Twente
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Autumn leaves are a reoccurring problem on the Dutch railways (and in many other countries as well). Their residue on the rails can significantly reduce the friction between wheel and rail, and thus make it harder for trains to accelerate and brake. In extreme cases trains can overshoot stations, and get wheel flats when the brakes lock. Due to this reduces friction, trains are not able to stay on schedule resulting in accumulating delays at busy tracks.
In order to reduce the problems several systems have been suggested and tested over the last years. The most recent one is the laser railhead cleaner, which is an idea originating in England. In order to get a clear idea of the effectiveness of this system, ProRail preferred to have independent, accurate measurements of the friction coefficient of the track, both before and after treating it with the LRC.
In order to do these measurements a trainmounted tribometer is being developed by a partner under the supervision of TU Delft and University of Twente. By being mounted directly on one of the axles of the train, this system will have the unique capabilities of doing direct measurements of the friction coefficient between rail and wheel, without any needed adjustments for scale.
In the coming year, this tribometer will be used to test the effectiveness of the LRC and possibly other methods for increasing the friction as well. These tests will lead to direct recommendations to ProRail and NS on which measures can be deemed effective enough for large scale use, and at which frequency they will need to be used on track. This will lead to a better understanding of the problems in the autumn, and possibly reduce the number of autumn-related delays in the future.