Testing of Fastenings
Both elastic and rigid fastenings
are tested in the laboratory for their suitability in the field. The vibrogir
and pulsator are used to test these fastenings.
The vibrogir is used in
laboratories for checking the effectiveness of various fastenings. With the
help of this equipment it is possible to produce high-frequency vibrations in
the laboratory, very similar to those produced on a real track. By applying a
frequency of 50 Hz, the rail and sleeper are made to vibrate at a rate of
700-800 Hz with an acceleration of 70 g and an amplitude of the order of 0.1-
0.3 mm. One hour of working of a vibrogir corresponds to almost 4.05 GMT of
traffic and 300 hours of its working creates the same effect on a fastening as
20 years of service under normal track conditions.
The pulsator not only simulates
vibrations just like the vibrogir, but also applies vertical and lateral
pressure on the rail fastening at a frequency of 250-500 cycles/ minute.
carried out with the help of vibrogirs and pulsators clearly establish the
superiority of elastic fastenings over rigid fastenings.