Evaluation and enhancement of the post-derailment passive safety performance of train cowcatchers

Train components often act as Substitute Guidance Mechanisms (SGMs), providing essential passive safety protection in derailment accidents. Although the train cowcatcher is obviously one of SGMs, its passive protection mechanisms and safety performance are poorly understood. This study investigates the post-derailment passive safety performance of train cowcatchers and introduces a novel guide-limiting device (NGLD), featuring a guide-limiting plate, to enhance post-derailment protection. The individual and combined effectiveness of the cowcatcher and NGLD in controlling vertical and lateral movements of derailed trains was evaluated through nonlinear finite element analysis (FEA). The results demonstrate that the combined reduces lateral deviation and vertical displacement by 11%-37%. Furthermore, post-derailment trains were constrained within 11.8 m of the track centerline. Notably, the installation position of the NGLD is critical, as abnormal position can increase lateral deviation. In conclusion, the train cowcatcher serves as an important SGM, while the NGLD enhances passive safety by reducing potential damage and improving train stability in derailment scenarios.