A fast simulation approach to assess draft gear loads for heavy haul trains during braking

Train traction and brake dynamics simulations can be used to improve the safety and efficiency of heavy haul transportation. Virtual models can be used to analyze many operational conditions that are expensive or inviable to be measured due to costs and security risks. This paper presents a low computational cost simulation model that encompasses the longitudinal dynamics equations and the pneumatic brake system behavior. The model is used to evaluate the effects of the locomotive traction/dynamic-brake and of the pneumatic brake delays in the draft gear forces. A real-world scenario was analyzed, in which a standard train control procedure was applied for 168 ore freight cars propelled by two locomotives. For this analysis, the model was able to perform up to 8 simultaneous parallel simulations with a processing time of 607 s to conclude a route of 2884 s, which is very suitable for this kind of investigation.