Adhesion Considerations in Safe Braking Distance Calculations

The main objective in optimizing train control is to eliminate the waste associated with the use of “worst case” assumptions to calculate Safe Braking Distances (SBD). Worst case takes the most conservative approach to the determination of train stopping distance in order to provide adequate stopping distance under virtually all conditions. This leads to stopping distances that could be far more than actually required under the circumstances at the time the train is attempting to brake. Several factors are considered in SBD; however one variable that influences a great portion of this distance is adhesion. This paper investigates adhesion to illustrate this influence on SBD and uses empirical data from Light Rail Systems with various test conditions. The interaction of the train control and other vehicle borne systems with SBD calculation will also be investigated including slip/slide control and brake assurance.Copyright © 2015 by ASME