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.Atest systemthat 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.