Eddy Current inspection may be a technology whose time has come.
Gage Corner Cracking (GCC) of rail and wheel from Rolling Contact Fatigue (RCF) has been historically difficult to measure due to technology limitations in quantifying the length and depth of such cracks. Even though ultrasonic inspection of rail takes place on a daily basis in North America, the technology of ultrasonics is limited to internal rail defects and does not lend itself to detect surface defects in most cases. Other technologies for detecting surface defects have been trialed with little real world success due to implementation limitations, accuracy concerns, and scaling issues.