Tread Metal Buildup on Railroad Freight Car Wheels: Dynamometer Simulation

The occurrence of tread metal buildup in service is infrequent. However, its presence can influence the performance and safety of the vehicle. Positioning may be a problems the wheel travels through curves on the rail. Additionally, the metal buildup on the tread produces an out-of-round condition, which can lead to high impact loads into the track structure as well as the rolling stock. The impact loading can produce premature failure of these components also imposing a safety risk. The objective of this research was to produce tread metal buildup on wheels tested with Transportation Technology Center, Inc.'s dynamometer, while simulating conditions by which it forms in service. In an attempt to simulate these conditions, a test matrix was created that included a range of brake pressures to simulate proper and improper brake operation. Additionally, a water spray was added to the wheel intended to influence the friction between the wheel and brake shoe to emulate wet conditions. The ability to produce tread metal buildup in the laboratory during dynamometer tests was intended to allow modifications to equipment and/or train handling to reduce the occurrence of this phenomena in service. The conditions under which tread metal buildups have been consistently observed to occur in service include rain and/or snow at times in combination with improper brake operation.


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Test Report
  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 94p

Subject/Index Terms

Filing Info

  • Accession Number: 01002675
  • Record Type: Publication
  • Report/Paper Numbers: DOT/FRA/ORD-03/25
  • Contract Numbers: DTFR53-93-C-00001, Task Order 136
  • Files: NTL, TRIS, USDOT
  • Created Date: Jul 28 2005 9:55AM