Manfred Bauer

Last modified: 2017-02-28


In principle, any rolling load generates vibrations. When passing switches, there is an increase of vibration emission caused by railway traffic. Especially at high speeds and high axle loads, significant vertical forces occur due to dynamic loads at the tips of rigid frogs. Additionally, wheels striking the check rails induce jerky horizontal forces. In switches with movable frogs, compared to types with rigid frogs, the gap at the frog is closed. On the basis of numerous measurements on simple switches with rigid or movable frogs, the differences of the vibrations are investigated and compared with literature references. The measurements of the selected switches show that, especially within the frequency range of 30 Hz and poor track quality, trains passing a switch generate a significant increase of vibration emissions. Furthermore, the vibration gain between switch and open track decreases with the distance from the switch to the observer. In one measurement, all regional trains passed a switch with rigid frog with changing directions. Independent from the direction of travelling, these regional trains caused similar vibrations. Movable frogs, however, are suitable for vibration reduction: They amplify the vibration emissions less than switches with rigid frogs.


vibration; switch; rigid frog; movable frog; vibration gain

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