Strategy for Alternative Occupant Volume Testing

This paper describes plans for a series of quasi-static compression tests of rail passenger equipment. These tests are designed to evaluate the strength of the occupant volume under static loading conditions. The research plan includes a detailed examination of the behavior of conventional equipment during the 800,000-pound buff strength test. The research will also include a demonstration of an alternative static test that is designed to load and test the occupant volume at a location other than the buff lugs. The alternative test will demonstrate a testing and evaluation method for the occupant volume strength of passenger rail cars that accounts for the collision load path through the occupant volume. Per current Federal Railroad Administration (FRA) regulations, all passenger cars must support an 800,000-pound static load applied to the car’s line of draft without undergoing permanent deformation. However, more operators are looking to introduce equipment built to foreign standards. Many international manufacturers are implementing alternative designs that make use of crash energy management design features, articulated truck designs that span two cars, and low floor designs. These changes in the form and function of the designs require alternative means of applying a compressive load to assess occupant volume strength. FRA has reviewed several proposed alternatively designed equipment under requests for waivers for specific corridors of operation. Because the number of requests has increased significantly, FRA is trying to establish reasonable alternative means for assessing adequate and equivalent occupant volume strength to conventional equipment. This paper proposes an alternative static test procedure that will provide a means of evaluating a similar level of occupant volume integrity and passenger protection during a collision. The test will allow for greater design variation for newer rail cars and cars built to foreign standards. For the alternative test, the load may be introduced through the available structure at the floor level and at the roof level. These loading locations will enable the load to be applied directly into key longitudinal members in the load path of collision loads through the occupant volume. Finite element models are used before testing to determine appropriate alternative load levels and locations. The test article is a modified Budd Pioneer car. No significant modifications are planned for the longitudinal members of the car, or for the occupant volume.