Kim Bowling is Director of Advanced Engineering for CSX Transportation. She received her BE from Vanderbilt University in Mechanical Engineering and later completed an MBA at the University of Florida. She joined CSX as a Management Trainee in 1991 and the following year was hired as a Facilities Engineer in Baltimore, MD. Later in 1992 she was promoted to Mechanical Systems Engineer and moved to CSX Transportation headquarters in Jacksonville, FL. In 1997 she was promoted to Manager AAR Services and from 2002 to 2004 she was a Blackbelt/Six Sigma for CSX. In 2004 she was promoted to Director of Process Engineering and in 2007 became Director of Car Design. Over the last few years in CSX Mechanical Operations she was a member of the AAR's Coupling System and Truck Casting Committee and became CSX's expert in truck performance measurement. In this role she has been performing truck "teardowns" to compare actual truck conditions to detector measurements for two years, and in July this year she moved to her current
The three-piece truck is the standard design used on nearly all freight cars in North America, as well as many other heavy-haul freight railroads worldwide. This design has become popular because it combines low initial cost, ease of maintenance and relatively good performance. However, these trucks are not without their limitations and certain types of wear and defects can dramatically affect their performance causing problems to the railcar, infrastructure, and potentially affecting safety.
In order to better monitor truck condition and performance CSX Transportation has installed eight wayside Optical Geometry Detectors at various points in its network. These detectors monitor the trucks on each railcar passing by the detector site and measure the wheelsets' angle of attack and lateral position with respect to tangent track. In the research to be discussed, the objective was to determine the source of certain extreme truck geometry conditions that these detectors measured. CSX performed 19 "teardowns" of trucks identified by the optical geometry system as having a potential problem. Additionally, many other cars with geometry exceptions have also been inspected at repair tracks. This presentation will summarize how the defects found relate to these exceptions. CSX has primarily looked at trucks with progressive and repeatable tracking problems, which cover 87% of the geometry exceptions. Key truck measurements recorded include: circumferential wheel tape size, digital wheel profiles, side bearing set up height, center bowl dimensions, side frame length and the distance between the thrust lugs. Many of the geometry exceptions seem to have been caused by mismatched (or asymmetrically worn) wheels. Differences in the circumference force the axle to shift laterally and allow the wheel to continually flange on the gauge side of the rail.