Specific features of the railcar kinematics causing rolling stock derailment when traversing turnouts

This study focuses on issues of improving train safety on challenging railway track sections, including mountain pass lines and station tracks, with a particular emphasis on the railcar-track system. Objective: to identify non-obvious causes and relationships leading to rolling stock derailment when passing through turnouts. Methods: this research adhered to the established methodological framework for investigating derailment incidents as sanctioned by the regulatory protocols of JSC “Russian Railways”. In addition, the Universal Mechanism software package was used to simulate and evaluate the dynamic behaviour of the railcar. Results: the findings indicate that localized degradation in specific rolling stock components, such as the automatic coupler, can induce significant lateral forces. These forces are sufficient to cause wheelset unloading, thereby an increased risk of derailment. The study analyzed the interaction between the wheelset and the track under standardized parameters, resulting in the generation of graphical dependencies illustrating the lateral and vertical forces arising at the wheel-track contact. Practical significance: the results of the study make it possible to reconsider the issue of rolling stock-track interaction by incorporating updated concepts regarding the internal and external kinematics of railcars. The investigation concludes that even minor deviations in the technical integrity of individual parts can have a profound effect on operational safety. Thus, the necessity for developing a more precise methodology for safety assessment based on these technical nuances.