Train-to-Train Impact Test: Occupant Protection Experiments

This paper describes the results of the occupant protection experiments included as part of the train-to-train impact test conducted at the Transportation Technology Center in Pueblo, Colorado on January 31, 2002. In this test, a cab car-led train, initially moving at 30 mph, collided with a standing locomotive-led train. The initially moving train included a cab car, three coach cars, and a trailing locomotive, while the initially standing train included a locomotive and two open-top hopper cars. The hopper cars were ballasted with earth such that the two trains weighed the same, approximately 635 kips each. The cars were instrumented with strain gauges, accelerometers, and string potentiometers, to measure the deformation of critical structural elements, the longitudinal, vertical, and lateral car body accelerations, and the displacements of the truck suspensions. As part of the test, the cars were equipped with instrumented test dummies seated in three interior arrangements: 1. Forward-facing unrestrained occupants seated in rows, compartmentalized by the forward seat in order to limit the motions of the occupants. 2. Forward-facing restrained occupants with lap and shoulder belts. 3. Forward-facing unrestrained occupant seated in the locomotive operator seat. The longitudinal, vertical, and lateral motions of the cars during the train-to-train impact test are discussed in the paper, as well as their influence on the responses of the instrumented dummies. The lateral motions of the cars had some influence on the response of the test dummies, however the vertical motions of the cars had a greater influence on their response. During the test, the cab car overrode the locomotive. This large upward vertical motion of the cab car helped the test dummies in the cab car remain in their seats. The longitudinal motions of the cars during the train-to-train test had lower injury potential than the longitudinal motions of the cars in the previously conducted single- and two-car impact tests. (In these tests, a single car impacted a fixed barrier and two coupled cars impacted a fixed barrier, respectively. Test dummies were also included in both of these tests.) In the train-to-train test the test dummies endured a much longer crash pulse, with a lower average longitudinal acceleration than in the single-car and two-car impact tests. In the train-to-train test only one unrestrained test dummy landed in the aisle after impacting the seat in front of it. All injury criteria values remained below threshold values.