Due to the long history of railroad companies around the
world, varying means of examination according to the
specifications for the different railroad components have
been carried out based on the general industrial progress of
the country [1 –3]. For more than 50 years the application
of customized ultrasonic techniques for the examination of
railroad components has increased, in comparison to
conventional ultrasonic techniques used until the end of
20th century. In this traditional atmosphere some accidents
have disturbed the silent harmony of companies involved in
the production of critical parts. More than ever high-speed
modern trains require modern and advanced examination
techniques [4 –11]. For practical application new ultrasonic
and eddy current techniques [12 –14] have been developed
and optimised in cooperation with Die Bahn AG (German
railroad carrier). In the present contribution the inspection
of railroad wheels and the railway track gauge corner will be
described. The ultrasonic technique used for the
examination is based on modern ultrasonic flaw detectors.
Using a rail-inspection train, railroads are continuously
checked for traffic-induced defects because high train speeds
and heavy axle loads are the critical factors affecting the
service life of the rails. Up to the present time, only ultrasonic
inspection was used. In addition, eddy-current inspection
could successfully and efficiently be used to detect and
evaluate certain surface cracks—so-called head checks. There
have already been reports about laboratory tests, which
proved the general suitability of this test method [12,13].
The next step—described here—consisted of practical trials
under real-life conditions. A test system that is able to fulfil the
strict requirements (test speeds of up to 100 km/h, complex
probe guidance, suppression of electrical and mechanical
interference, recording of data, filtering and evaluation of
data) was developed. As part of the rail-inspection train and as
a manual system, this inspection system was successfully
tested on railroads under real conditions.