Innovative axle-end design to enhance in-service UT

The new axle-end design – blind hole – has been developed and patented to increase the coverage on ultrasonic inspection of solid axle.
The inspection can be performed in-service (5’/axle) without the need of disassemble the wheelset from the train, only need to remove axle-end cap and axle-box lid.
The best results are obtained using a phased array UT system with 2 complementary probes (4MHz) so that inspects the entire axle volume inspection form each axle-end.
The scanning is performed automatically: once the probe holder is placed in the blind hole, the integrated motor rotates the probes while an encoder provides the reference angle position.
The result of the inspection is a map (longitudinal direction and angle on main axes and magnitude on hysometric coloring) with the position of the indications.
Most of the existing axles may be re-designed to incorporate the blind-hole improvement. The phased array system could be used to inspect each type of axle with blind-hole of the fleet.
With the LAx®141 the ESFA-based design is being further developed in order to increase the advantages offered by the phased-array technique.