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John Peters

John Peters
Union Pacific Railroad

David Elvidge

David Elvidge
L.B. Foster Company


The Effect of Train Mounted TOR-FM on Wheel Life and Defects

Over the past decade, numerous studies have identified the effects of Top of Rail friction modifier application on key parameters such as lateral forces, rail wear, fuel consumption and RCF. In principal reductions in wheel wear and RCF related defects may be anticipated (and have been suggested by wheel / rail modelling by TTCI), no data has existed to substantiate this effect. Largely this is because TOR-FM has mostly been implemented on freight railroads using wayside application. As such, only a small portion of total wheel rotations on a typical route will experience TOR-FM application.

In this paper we report on wheel life impacts from a fleet of unit coal trains with AutoPilotTM train mounted TOR-FM application that have been operational for more than three years with application of dry film KELTRACK friction modifier. Unlike in wayside application, all wheels on these trains see TOR-FM application on a consistent basis.

Analysis has focussed on:

  1. Car repair data on wheelset changes using appropriate Why Made codes that are expected to be related to TOR-FM
  2. Wayside wheel profile measurements on an individual wheel basis.
  3. WILD site data focussing on vertical load impacts

Comparisons were made between coal train trains running over essentially identical routes to two power utilities, one whose fleet was largely equipped with AutoPilot TORFM, and the other without. Comparisons were also made on a time basis before and after TOR-FM implementation. The analysis focussed on a select pool of cars that had maximum in service time, to allow data normalization based on million ton-miles.

The results showed >40% reduction in flange height development rates (e.g. tread wear) for the TOR-FM treated wheels. In addition reductions, in wheelset changes were documented related to Why Made Codes 75 (shelling), 60 (thin flange), 64 (high flange), and 65 (high impact wheels) on the AutoPilot trains compared with “baseline” coal trains.

These results validate confirm the positive impacts from a dry film friction modifier on wheel wear and in particular RCF, and provide a significant additional impetus for implementation of train mounted TOR-FM especially for car owners and those paying for car maintenance.