Critical velocity measurements of freight railway vehicles roll-over in wind tunnel tests as the method to assess their safety at strong cross winds

Railway vehicle roll-over under strong cross-wind action is significant problem considered in the context of vehicle aerodynamics. Train accidents induced by wind occurring in last two decades resulted in safety procedures concerning this phenomenon included in specifications or standards. Assessment of railway vehicle aerodynamic stability is conducted on the basis of roll-over critical velocity, hence velocity causing vehicle overturning. All of the methods concerning this topic suggest to calculate roll-over critical velocity from equilibrium equation, where aerodynamic characteristics of the vehicle are taken into account in the form of aerodynamic coefficients. These coefficients can be mainly obtained from measurements on aerodynamic balance or assessed for specific train. This paper presents different method to define stability of rail vehicles under strong cross-wind action. Presented tests results show that roll-over critical velocity can be obtained directly from wind tunnel model tests. This method seems to be appropriate, more accurate and simpler than indirect determination of the roll-over critical velocity using aerodynamic coefficients by following the common procedures referring to cross-wind assessment of railways.

Automated summary

This study discusses the stability issue of railway vehicle roll-over under strong cross-wind action, and proposes a method to directly obtain the roll-over critical velocity from wind tunnel model tests. Compared to the traditional method of indirectly determining the roll-over critical velocity using aerodynamic coefficients, this approach seems to be more appropriate, accurate, and simpler.