Limitations in size and type of detectable defects in rail flaw inspection

Rail flaw data from commercial railroad rail inspection systems is analyzed. The data is based on experimental work performed at the Transportation Technology Center Inc. Major US railroads provided defective rail that had been removed from service. The rail, containing a variety of defects, was placed into a test track. The test track was used to test and compare the performance of commercial rail flaw detection systems. While 49 defects were present in the test track, 44 defects were used for sizing studies. Data is shown for six test runs from which probability of detection curves are obtained. Data regarding the types of defects that were not detected also provides research needs information for the NDE community.