Technical Reports

Wheel Rail Forces Measured Under Severe Track Geometry Alignment Variations

  • 01
  • Jan
  • 2001
AUTHOR: M. Coltman, H. S. Lee, H. Weinstock
SUBJECT: Track/Train Interactions
KEYWORDS: Rail Vehicle Response, Track Perturbations, Lateral/Vertical Wheel/Truck Forces
ABSTRACT: This report describes a series of vehicle track interaction tests conducted from October 1984 to December 1984, under the Federal Railroad Administration (FRA) Improved Track Safety Research Program, at the Department of Transportation, Transportation Test Center (TTC) at Pueblo, Colorado. The test results provide a base of measured data on a broad range of track geometry irregularity amplitudes and wavelengths, over a range of operating speeds for three types of freight cars, in loaded and empty conditions,' with two types of wheel profiles. The types of rail cars tested included 100-ton open hopper cars, 70-Ton Flatcars and 100-Ton Tank Cars. The rail cars were tested over specially constructed track test sections which had sinusoidal alignment perturbations with 39 foot, 50 foot, 75 foot and 90 foot wavelengths. The amplitudes of the perturbations were selected, using the results of analytical simulation studies to provide approximately equal dynamic severity at the critical operating speed for the most critical train consist for that section. The cars were tested in both loaded and unloaded conditions and with AAR new wheel 1/20 profiles and with a Heumann worn wheel profile. The results of the tests are presented as plots of peak wheel rail force as a function of speed for each of the cars and test sections.