Detail fracture growth in rails: Test results

Abstract The term ‘detail fracture’ describes a common type of transverse fatigue-crack defect found in rails in U.S. railroad service. Detail fractures tend to comprise the major proportion of defects in continuous welded rail, and thus assume increasing importance as U.S. railroad track is modernized. The frequency at which one should periodically inspect rails to detect detail fractures ahead of rail failures thus has an important bearing on railroad track quality maintenance programs. A recent experiment has established typical growth rates for detail fractures in heavy rail sections in tangent track. This paper summarizes the experiment results and some related field observations. In a separate communication, a simple fracture mechanics model is applied to the data to provisionally extrapolate the results to other situations of interest.