Effects of top-of-rail friction modifiers on the friction, wear and cracks of railway rails
The goal of the research conducted for this project has been to investigate the effect of top-of-rail friction modifier on the wear, RCF and friction of rails and calculate the life cycle cost of a TOR-FM system.
Goal
Deliver new knowledge to Trafikverket and LKAB, so they are able to conclude if and how the implementation of the Top of Rail lubrication system will result in net savings and other possible advantages for rail
and wheel, respectively.
Projects status and results
Naturally Trafikverket want to prolong the lifetime of rails as much as possible. One methods to do this is by lubricating the top of the rail with friction modifier (TOR-FM). A friction modifier is a sort of lubricant which by the suppliers are argued to ensure that the friction will not be too low (which can cause unacceptable braking distances) and at the same time will reduce both cracks and wear. Also the supplier argues that not much TOR is needed and that the carrying distance is long enough from economical point of view. However, the experiences from other places over the whole world using TOR-FM differs a lot, which was the motivation for the present project.
Thus the overall goal was formulated to deliver new knowledge to Trafikverket and LKAB, so they are able to conclude if and how the implementation of the Top of Rail lubrication system will result in net savings and other possible advantages for rail and wheel, respectively. In order to solve this goal a comprehensive field test was conducted as well as theoretical simulations in GENSYS software and friction and wear test in CBM Lab. The most important results are that the potential for TOR-FM to reduce both wear and cracks are substantial, but way side TOR equipment is not recommended since the total costs due to maintenance issues of these equipment will be too high. Mobil TOR-FM equipment on locomotives seems to be a much better solution from LCC point of view. Also the performance of different types of TOR-FM shows large variations, for instance too short carrying distance or uneven friction characteristics. The main conclusions are:
- Way side TOR equipment is not recommended
- TOR-FM show an impressive potential to reduce both wear and cracks on rail
- Mobile TOR-FM equipment on locomotives should be investigated further and a sort of Win-Win agreement between Trafikverket and operators should be discusse
- Be sure to use the correct type of TOR-FM
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