System to Detect Truck Hunting on Freight Railroads. Final Report for Safety IDEA Project 06

摘要

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. Railroads are currently deploying different wayside devices to assess car performance and car component condition as a means of reducing car and track damage and reducing the 'stress state' of the railroad. If successful, a wayside truck hunting detection system could provide valuable information to the railway industry by monitoring the dynamic lateral stability performance of all passing freight car trucks. The Transportation Technology Center, Inc. (TTCI) proposed and 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. The proposed system was developed using two stages. The first stage (Stage 1) was a laboratory stage, and the second stage (Stage 2) was on-track testing. During Stage 1, fiber-optic DMS were selected and tested for the performance characteristics necessary for truck hunting detection. Test results indicated that the selected sensors were unable to perform well in this application. An expert review panel recommended that an alternative DMS-based truck hunting detection prototype be evaluated in Stage 2 of the project. This prototype, developed by an Australian company known as Lynxrail, is based on an approach that uses inductive proximity DMS in an array along a section of tangent track.