Overturning and Equilibrium Speeds and Speed Safety Margin—A Sensitivity Analysis

Abstract

Two critical speeds viz., the equilibrium speed and the overturning speed, are recognized to play an important role in defining operational and safety characteristics of railroads. An analysis of the sensitivity of the critical speeds to important operating parameters is presented. Two parameters called the ‘Speed Safety Margin’ and the ‘Speed Factor’ are defined to assist in evaluating the severity of a set of operating conditions. It is concluded that degree of curve has the most drastic effect on safety followed, in decreasing order of effect, by height of CG, superelevation, and track gage. Some comments are offered as a possible guide to safe and economical operation of railroads.