A method to improve draft gear designs for heavy haul trains

This paper introduces a method to improve draft gear designs for heavy haul trains. Improved designs are expected to achieve smaller coupler fatigue damage and lower in-train forces. The method used Longitudinal Train Dynamics (LTD) simulations, coupler fatigue damage calculations and a Genetic Algorithm (GA). An advanced draft gear model was used in this method. The advanced draft gear model has considered all components in the draft gear and their geometries. It is directly related to the structures of the real draft gear design; the developed method can therefore be used to guide future designs. A case study was conducted to show the feasibility and effectiveness of the method. The case study shows that there area number of different designs that can achieve both lower in-train forces and smaller coupler fatigue damage when compared to the original design. The resulting optimised design can double the fatigue life of coupler system components and achieve a 13% reduction in terms of the maximum in-train forces.