Abstract
The complexities of the motion of a locomotive are such that accurate solutions of the equations of motion have little engineering value. In previous papers the author has given an energy method of calculating the critical speed, above which the locomotive can sustain steady oscillations. This method is extended in the present paper to cover the effect of wheel coning and to study the possible motions at speeds above the critical. Energy gain from rough track is also estimated. An alternative method of study is outlined in which the flange forces are assumed to be sinusoidal with “equivalent” stiffness factors. A simple case is solved to show how relations between flange forces and frequency of oscillation can be obtained which are of practical value in design.