Abstract: A system for detecting the presence of a rail end in a rail of a railway track includes a support structure mountable to a component of a rail vehicle. At least one magnetic field generator is carried by the support structure to generate a remanent magnetic field in the rail. A sensor arrangement is carried by the support structure in spaced relationship to the magnetic field generator to detect magnetic flux leakage associated with the remanent magnetic field. The sensor arrangement includes at least one pair of longitudinally spaced sensors, each sensor generating a measured signal based on the magnetic flux leakage detected by that sensor. A signal processing module is responsive to the measured signals to calculate a differential signal from the measured signals of the sensors of the at least one pair of sensors. The differential signal is indicative of the presence of a rail end in the rail.

Abstract: A system for detecting the presence of a rail end in a rail of a railway track includes a support structure mountable to a component of a rail vehicle. At least one magnetic field generator is carried by the support structure to generate a remanent magnetic field in the rail. A sensor arrangement is carried by the support structure in spaced relationship to the magnetic field generator to detect magnetic flux leakage associated with the remanent magnetic field. The sensor arrangement includes at least one pair of longitudinally spaced sensors, each sensor generating a measured signal based on the magnetic flux leakage detected by that sensor. A signal processing module is responsive to the measured signals to calculate a differential signal from the measured signals of the sensors of the at least one pair of sensors. The differential signal is indicative of the presence of a rail end in the rail.

Abstract: A method and apparatus for high speed magnetic detection of surface fatigue cracks in railway rails. The magnetic material of the rail is magnetized by touch magnetization using a permanent magnet (31), leaving a remanent magnetic field. A sensor head (30, 50) having a plurality of Hall effect sensors (32) senses stray flux generated in the vicinity of surface fatigue in the rail head by the remanent magnetic field. The sensor head (30, 50) may incorporate a proximity sensor (60) to compensate for variations in sensor height. The apparatus may be mounted on a conventional track recording vehicle (TRV) for use in routinely monitoring the surface fatigue severities in rail along a railway.