Technical Reports

Validating Electromagnetic Walking Stick Rail Surface Crack Measuring Systems

  • 28
  • Jun
  • 2016
AUTHOR: Federal Railroad Administration
OFFICE: RPD
SUBOFFICE: RPD-31
REPORT NUMBER: DOT/FRA/ORD-16/23
KEYWORDS: electromagnetic walking stick systems, surface breaking cracks, crack depth measurement
ABSTRACT: A series of field studies were undertaken to evaluate electromagnetic walking stick systems and their ability to measure the depth of damage from surface breaking cracks. In total, four railroads, and four suppliers participated in the project. The walking sticks were able to determine whether cracks are present and, after multiple runs, whether crack length is increasing or declining. None of the evaluated units were able to accurately quantify crack depth. While the crack depth predictions most often exceeded the “measured/real” values, sometimes by 200 or 300%, the systems can determine where along the track (and where across the railhead) that cracking is present. This information may be useful for planning of rail grinding, monitoring and trending the progress in reducing and eliminating cracks, identifying clusters of damage at high resolution and point to localized problems with track geometry or other errors. Lastly these tools could be used to qualitatively evaluate the effectiveness of, for example, friction management, improved profiles and steels in mitigating surface fatigue.

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