Hamburg/Eschede (dpa/lni), (translated by NDTnet)
- Another expert has blamed the Deutsche Bahn for last week's ICE accident. Although the DB was aware that rail wheels of this type should be tested with ultrasound every 2-3 days, the implementation of such a system was not pursued aggressively enough, Dipl.-Ing. Rolf Diederichs, publisher of an Internet journal about ultrasonic testing (www.ndt.net), told DPA on Wednesday. "Even though the necessity for more stringent testing was known, there seemed to be no sense of urgency to do anything about it, although state of the art equipment and technology were available, " said Diederichs.
Hegenscheidt pioneered a system in 1992, which was integrated into the Hegenscheidt-Diagnostic-systems of Hamburg in that same year, and in Munich in 1994. This system is used to test the wheels of those trains every few days.
The DB had originally planned to establish this system for the ICE train wheels officially. According to Diederichs, "They knew that during operation, defects can occur that can break the wheel, otherwise, why would they even have been considering applying the testing procedures to address that?"
The manager of Hegenscheidt, Klaus-Peter Schwarz, confirmed that the systems have been installed in Munich and Hamburg, in 1994, and 1992, respectively. These systems consist of three modules: roundness measurement, profile measurement and the ultrasonic unit to detect the cracks. However the ultrasonic unit showed evidence of unreliability, because signals coursed by "irrelevant surface cracks could make the important cracks invisible." For that reason the ultrasonic unit was switched off in Hamburg 1993 and in Munich it was not used for continuous testing.
However, according to Schwarz, the unit was undergoing further testing. "From these results a completely new ultrasonic unit for crack detection was developed. It will be tested in the next three weeks in Hamburg."
Currently experts are discussing better solutions in the online-Forum of the professional journal «The e-Journal of Nondestructive-Testing and Ultrasonics» (www.ndt.net).
In addition to other articles, the site has published a lecture given by
DB employee Hartmunt Hintze,
who points out the problems of the Hegenscheidt-system and an outlook on
"Meanwhile the technical modifications have been applied, and the trials are
in preparation," he says.
(dpa/lni hu yy ek) (translated by NDTnet)
Die Deutsche Bahn versucht abzulenken Bessere Lösungen der Ultraschalltechnik wurden jahrelang versäumt einzusetzen.