The HSRCA is an instrument that is designed for corrugation surveys of a complete and fairly large railway system at relatively high speed (typically 80km/h or more). It is extremely robust and reliable: the earliest version of our system has been used routinely in Australia since 1987, without significant need for maintenance. The most recent version is used routinely by the state railways in Italy (FS), while other versions have been used in Poland and in Israel. Calibration of the HSRCA is typically verified by using both it and the CAT to measure the same length of track.

One of the most useful forms of output from the HSRCA, taken from measurements made over a 35km length of track in Italy, is illustrated here. The upper and lower parts of this Figure show data for the left and right hand rails respectively. The data shown are the so-called "percentage exceedences" for corrugation in different wavelength ranges as functions of the corrugation amplitude in microns SQM (i.e. RMS or root-mean-square). For example, for the left hand rail in the 30-100mm wavelength range, corrugation exceeded 20 microns RMS over about 50% of the 35km stretch of track, and 40 microns RMS over about 10% of the track length. Presentation of data in this format helps to establish simple objective criteria for grinding such as, "Any 200m length of track should be ground when corrugation on either rail in the 30-100mm wavelength range exceeds an amplitude of 10 microns RMS over at least 50% of the site, or 20 microns RMS in the 100-300mm wavelength range."

Further information on the accuracy and repeatability of our corrugation measurement products is given here.

A comparison of our product specifications and use is available here.