Maximum Curving Speed

Abstract

Full equilibrium superelevations are rarely installed on tracks. Consequently, trains run on unbalanced superelevations. Currently, the maximum curving speed is modeled with blanket unbalanced superelevations. Blanket unbalanced superelevations are not desirable for all actual superelevations, regardless of their values. In this paper, the maximum curving speed is modeled to ensure comfort and safety, considering two primary parameters: the curve parameters and the vehicle characteristics. The curve parameters include radius and actual superelevation, and the vehicle characteristics include the height of the center of gravity (c.g.) on top of the rail and the suspension factor. The proposed model has interesting features. It suggests that unbalanced superelevation is proportional to actual superelevation. The maximum curving speed is evaluated against the normal operating speed as the base reference. The model is applied and validated from the point of view of both comfort and safety. The paper suggests a method to divide equilibrium superelevation into actual and unbalanced superelevations.