Developing CEM design standards to improve light rail vehicle crashworthiness

In recent years extensive effort has been devoted to the development of crashworthiness standards for rail cars spanning modalities from light rail to heavy rail and commuter rail applications. Each mode provides different challenges to the designer, whether it is designing against collisions with similar rail car designs, dissimilar vehicle designs such as freight rail vehicles or other obstructions such as pedestrians and street running automobiles. Structural standards in the U.S. and internationally are being developed to address these modes and provide a sensible approach to occupant protection. The advent of crash energy management (CEM) science as a means for better controlling the energy in a collision is being applied universally in rail car applications, yet there is variability on CEM design approaches to account for the variability in obstructions. This paper focuses on the development of CEM design for light rail vehicles in the U.S. based on efforts of the ASME Rail Transit Vehicle Standards Committee. A comparison is made between current LRV standardization efforts and recent commuter rail specifications that include CEM.