Railroad bridge condition evaluation using onboard systems

Transportation Technology Center, Inc. (TTCI) is investigating the feasibility of using vehicle-based systems to detect railroad bridge impairments to supplement regular bridge inspections. Test results show that an onboard track deflection measurement system and two different track geometry measurement systems are capable of detecting changes in pier elevations, and some of the systems can detect changes in bridge span deflection in an open-deck trestle. A series of tests detecting weak stringers and pier elevation changes in an open-deck trestle bridge was performed at the Bridge Deflection Test Facility (BDTF). This paper presents results from three vehicle-based systems in different test setups: (1) A track deflection measurement system and a track geometry measurement system were tested on a Federal Railroad Administration (FRA) track measurement vehicle, (2) another track geometry measurement system was tested on a lightweight passenger car, and (3) a track deflection measurement system was tested on a conventional hopper car.