Rails and parts of turnouts in the track can be non-destructively tested by ultrasonics for internal defects. This should prevent failures or accidents occurring due to the non-detection of defects in a timely manner.
The Ultrasound Test Procedure:
The pulse-echo technique is used for the railway permanent way. The short ultrasonic pulses are sent from the probe into the component and after reflection at an obstacle received back. In order to avoid an air gap, water or oil is applied between the probe and test item. In the ultrasonic testing device, the received pulses are amplified and displayed on the screen as echoes.
The rail testing train:
Defects in rails are detected by ultrasonic testing trains, so that they can be eliminated before they cause a rail fracture which might have a significant impact on the operation. The ultrasonic test runs are done with a test speed of between 40 up to a maximum of 110 km/h at specified intervals. The ultrasonic testing trains are equipped with several ultrasonic probes.
In addition, a hand-held testing device can be used for checking turnouts, tracks and other small parts. The probes are individually used in turnouts to collect readings from all areas of the turnout linkage, in particular, the crossings.