Dynamic Reactions in Hop Dampers for Bogie Undercarriages: Calculation of the Effects of Sudden Application of the Wheel Brakes Available to Purchase

THE function of hop damper units as fitted to modern multi‐wheel bogie undercarriages is to dissipate the kinetic energy of the bogie, wheels and brakes due to their rotation about the bogie attachment pin. This rotation of the bogie may be caused by impulsive application of the wheel brakes, and the purpose of the hop damper is to reduce the angular velocity of the bogie, so that when it comes up against itsstops, the angular velocity is substantially zero, thereby reducing the mechanical shock which may be felt in the undercarriage as a whole.