Improved crashworthiness of rail passenger equipment in the United States

The Federal Railroad Administration has been conducting research to develop strategies for improved passenger protection in train accidents. Crash energy management (CEM) has been developed as a strategy for structural crashworthiness. Interior strategies that have been developed to work in concert with CEM include improved workstation tables and optimized commuter seats. The purpose of this research is to develop the technical information required for passenger equipment specifications, standards, and regulations. Research results are being applied by METROLINK commuter railroad in their current efforts to procure new equipment. The American Public Transportation Association is planning to develop industry standards from these research results. Alternative strategies for structural crashworthiness and occupant protection are first evaluated for potential effectiveness. For strategies that appear promising, designs are developed; test articles are built and then tested. The effectiveness studies define the crashworthiness design requirements; the design studies show what is feasible. The design studies result in drawings, which are used to build test articles. The construction of test articles requires that the designs be sound. The tests confirm the design performance; the test conditions are derived from the effectiveness studies; and the test results are used to refine the effectiveness studies. This research methodology results in the information required to develop specifications, standards, and regulations. For some collision conditions, CEM equipment can protect all of the occupants for closing speeds that are more than twice the speed for conventional equipment. Preserving the space for the occupants does marginally increase the deceleration of the CEM cab car. For trailing equipment, the decelerations are similar in CEM and conventional trains. The improved workstation table and optimized commuter passenger seat designs have been developed to mitigate the marginal increase in deceleration. The research on workstation tables has been carried out cooperatively with the United Kingdom’s Rail Safety and Standards Board. Crashworthiness can be incrementally improved by the strategic addition of CEM and occupant protection features. Full-scale impact tests have been arranged to allow direct comparison of the crashworthiness performance of conventional and alternative strategies. Single-car and two-car impact tests of conventional and CEM equipment have been conducted. These tests have shown that CEM can preserve the occupant volume and limit the likelihood of derailment. In these tests, the conventional equipment lost occupant volume and derailed. In the train-to-train tests, a cab car led train traveling at 30 mph impacts a standing locomotive led train. In the conventional equipment test, the space for 48 occupants was eliminated. The CEM equipment test is planned for March 23, 2006. It is expected that the space for all of the occupants will be preserved and that injury criteria values will remain within survivable limits. Instrumented test dummies in the cab and first coach cars will be used to confirm these expectations. What’s new? Conventional and CEM equipment can safely be used in the same trains and CEM equipment can be introduced on a car-by-car basis, rather than a train-by-train basis.