Head Check Detection

Head  checks  (UIC  2223)  are  cracks  which  are  open  towards  the rail surface and which occur at a high frequency per metre. They are  encountered  primarily  at  the  gauge  face  of  the  outside  rails on a curve. The cracks running in parallel are located, depending on the on-site structural condition, rail quality and profile, at a distance of approximately 1 mm up to several centimetres in close proximity to each other. They spread at an angle of approximately 25° into the inside of the rail head and subsequently often continues parallel to the wheel pattern or tilt downwards. In the process, the periodically occurring head checks band together with the result of chipping at the gauge face of the rail or multiple fractures  of  the  rail  over  a  length  of  several  metres. Thus,  at  an  advanced stage the head checks have to be ranked as a particularly dangerous rail defect. In the last few years, the number of derailed trains,  some  very  seriously,  as  a  result  of  head  check-damaged rails has increased dramatically.
For this reason, many railway infrastructure companies rely on the experience of EURAILSCOUT in the testing of head checks by means of the inductive eddy current process which we have operated  on  an  international  level  since  2002. Working  in  partnership with our clients we are able to explore new avenues in the area of maintenance planning. The eddy current data recorded in the test is analysed by us and serves as an objective basis to plan rail maintenance. We also have the ability to develop complete grinding plans where we combine the data from the eddy current test with the results of the profile and corrugation measurement. This combined  analysis  serves  as  the  basis  for  a  cost-  and  time-optimised  maintenance  regime.  This  approach  enables  the  transition from a reactive to a proactive maintenance regime generating considerable efficiency improvements in the maintenance of your railway infrastructure.1.) Eddy current signal image of a head check- damaged rail  2.) Head check-damaged rail