Future Directions in Track Evaluation and Inspection
Association of American Railroads
Research, development and innovation in track evaluation and inspection techniques are very important and necessary, if improvements in track performance are to be made. This area represents one that will pay dividends to the railroad industry, both now and in the future. Although strong track does not always represent a strong railroad, a weak track and structure does, in fact, represent a weak railroad, and seriously limits it's performance abilities. Improvements in the performance of track, or the strength of track, have been sporadic, and, in general, late in coming. Many of our present day "improvements" had their origin in situations in which the existing technology was simply not adequate for the requirements of the day. Example would include the advent of control-cooled rail in the 1930's, to overcome the problem of transverse fissures from hydrogen embrittlement, the development of welded rail to reduce jointed track problems, the development of thermite weld technology for the field welding of rails, the development of alloy and heat-treated rails to reduce the problem of rapid bend wear, the refinement of bonding insulated joints to extend service life and the hardening of manganese steel to provide a longer lasting insert frog structure. Very little has been accomplished in defining, quantitatively, the required strength or performance of track, and the partial vacuum in this area has been filled only by various improvements in the service lives of individual track components. To be sure, research work in the field of track structures has been undertaken, both in this country and in Europe, as, for example, Talbot's work on vertical track modulus in 1918, the French National Railway's (SNGF) work in the late 1940's on their detailer wagon , and the U.S. Track Train Dynamics effort that began in 1972, which consolidated and expanded recent track-related research. In the United States. it has only been in the last ten years that railroads began to take a serious look at measuring the geometric deficiencies in their track by automated means (Figure 1). Even today, less than twelve Class 1 railroads own and operate their own track geometry cars. These cars measure the track irregularities, such as deviations in line, surface, gage and elevation, but not the strength of the track itself. These track geometry cars have probably been worth over one thousand times their initial cost to the railroads because they have been extremely successful in finding track locations that are unsafe, and in need of repairs. To a lesser degree, they have been successful in the statistical evaluation of geometrical data to compare the relative qualities of long segments of track . No definition or measurement of track strength, however, has been undertaken. In this paper, the authors would like to discuss present work and future trends in techniques for the evaluation of track performance and strength.
Track evaluation, Track performance
Lovelace, W. S., & Zarembski, A. M., “Future Directions in Track Evaluation and Inspection”, Track Train Dynamics Conference, Chicago, IL, November 1979.