Examining Wheel/Rail Interaction
Once a year, interested parties convene to discuss the latest research and developments in wheel/rail interaction technology. Delegates from around the world met at the Advanced Rail Management and Interface Journal's 12th Annual Wheel/Rail Interaction Seminar held in Chicago in May to explore issues ranging from "Initiatives to Improve Wheel Tread Performance" to "Advancing Rail Grinding Strategies." They looked at issues ranging from "Truck Detector-Based Car Inspection and Maintenance" to the "Effect of Combined Track Geometry Errors on Vehicle/Track Forces," among others.
"Regardless of our orientation or perspective, our ongoing goal is to come to a better understanding of the forces at work at the wheel/rail interface," said Gordon Bachinsky, President of Advanced Rail Management. And like it or not, there are issues to wrestle and lessons to be learned.
Research, for example, has shown that poorly performing cars introduce high costs into the overall system. They reduce car availability and overall system capacity, and increase (equipment and labor) maintenance costs. The Association of American Railroads (AAR) puts the tab for the current cost of capital and maintenance of poorly performing vehicles at $8.6 billion.
With numbers like that, it should come as no surprise that the Transportation Technology Center, Inc., has been investigating vehicle/track interaction through wayside (and onboard) detection systems that measure vertical and lateral loads. The effort includes interpreting Truck Performance Detector (TPD) data, for example, and relating it the physical condition of the cars. The TTCI has identified bad actors based on performance characteristics such as hunting behavior and warp conditions.
“If you were a car inspector, you wouldn’t think they needed much attention,” said Harry Tournay, a Scientist at the Transportation Technology Center, Inc.
To better understand what causes the poor behavior, the TTCI has torn down a number of cars that were flagged by TPDs. The results sometimes have been puzzling. "We found perfectly good cars that show intermittent behavior," Tournay said. "Other cars that were setting off alarms were torn down and no problems were found."