System to Detect Truck Hunting on Freight Railroads

Railroad cars can be subject to a lateral instability called hunting while running at relatively high speeds on tangent track. Hunting causes car, lading and track damage, and as a worse case scenario, possibly leads to derailment. This Innovations Deserving Exploratory Analysis (IDEA) project investigated a wayside truck hunting detection system that consisted of an array of paired displacement measurement sensors (DMS) placed along a section of tangent track on which trains operate at relatively high speeds. Speed, wheelset alignment, and lateral position relative to the track are established at each non-end sensor pair in the array to determine a particular wheelset’s path through the array to identify, among other things, trucks with poor lateral stability. In July of 2004, Norfolk Southern (NS), in conjunction with the Equipment and Operating Practices Research Division of the Office of Research and Development at FRA, conducted a comparative test of truck hunting detection systems as part of their ongoing cooperative agreement for wayside component inspection demonstrations. Transportation Technology Center, Inc. (TTCI) was allowed to participate in the evaluation using the Lynxrail prototype. The Lynxrail prototype performed reasonably well when compared with onboard data. Additionally, the prototype performed comparably to the other systems evaluated at the NS/FRA hunting test in July of 2004, according to an NS presentation at the Wheel/Rail Interaction Conference at Chicago in May of 2005. In the interim between the end of testing and the production of this report, Lynxrail completed several prototype enhancements needed to better support the operations of the North American railroad industry. These enhancements include: incorporation of Automatic Equipment Identification (AEI) interface capabilities, ruggedization of track-mounted system components, and protection of all system components so they can successfully function in all North American climates. Furthermore, the data from this evaluation was provided to Lynxrail, who was encouraged to continue optimizing its algorithms for improved detector performance at higher vehicle speeds. The Lynxrail system, now sufficiently mature, has been offered in several proposals to North American freight railroads. If desired, the Lynxrail system could equally serve to detect hunting for passenger railroads as well.