As a direct result of the industry's goal to improve the quality and safety of service to its customers, the Association of American Railroads (AAR) has embarked on a major research project to develop and implement automated inspection methods to effectively measure the available track stength, and to identify and repair the weak spots before further track degradation and increased maintenance are needed. The AAR has designed and constructed a track loading vehicle (TLV) which was used extensively in testing of track lateral restraint. This new vehicle is capable of applying computer controlled loads over a range of track conditions and measure the dynamic response of the track. The TLV is built on the underframe of a diesel-electric locomotive and features a retractable load bogie mounted underneath the center for applying computer controlled loads to the track and measuring the response while stationary or moving. The TLV was successfuly tested over 3,500 miles of revenue track to identify wide gage and weaker tie/fastener conditions. The test results have shown that it is feasible to implement automated inspection methods to effectively measure the available track strength, and to identify and repair the weak spots before further degradation and increased maintenance is needed. Substantial savings could be realized by the industry if positive identification of defective ties can be improved using test devices like the TLV.
Semih F. Kalay,
"Measurement of track strength using nondestructive evaluation techniques", Proc. SPIE 2458, Nondestructive Evaluation of Aging Railroads, (30 June 1995); doi: 10.1117/12.212680; https://doi.org/10.1117/12.212680