Technical Reports

Evaluation and Service Testing of Prototype Empty/Load Brake Device to Reduce Wheel Spalling Due to Slide

  • 01
  • Aug
  • 2007
AUTHOR: Scott Cummings, Larry Vaughn
SUBJECT: Braking Systems
KEYWORDS: Spall, Wheel Slide, Empty/Load Device, Brake Ratio
ABSTRACT: The Transportation Technology Center, Inc. and New York Air Brake evaluated a prototype three-step graduated empty and load (E/L) brake device to reduce wheel spalling due to wheel slide on intermodal double-stack railcars. Analysis of the results showed an increase in the rate of wheel spalling on the test wheelsets compared to a control group of wheelsets. There is no logical reason why the three-step graduated ElL device would cause more wheel slides than a conventional ElL device, possibly indicating that other factors influenced the test results. One test wheelset location produced two tread damaged wheelsets during the course of the test. Brake shoe force measurements during the initial inspection indicated poorly distributed brake shoe forces, although the wheelset position which developed tread damage twice during the test had lower than expected brake shoe forces. Brake shoe force measurements during the final inspection showed more evenly distributed forces. No other spalling developed on the test wheelsets. Two additional cars are currently equipped with graduated ElL brake devices to increase the sample size and hopefully produce a statistically meaningful result.