Test Requirements of Locomotive Fuel Tank Blunt Impact Tests

Abstract

The Federal Railroad Administration’s Office of Research and Development is conducting research into passenger locomotive fuel tank crashworthiness. A series of impact tests are planned to measure fuel tank deformation under two types of dynamic loading conditions. This paper describes the test requirements for the preliminary tests in this series — a blunt impact of conventional locomotive fuel tanks. Current design practice requires that Tier 1 locomotive fuel tanks have minimum properties adequate to sustain a prescribed set of static load conditions [1]. In accidents, fuel tanks are subjected to dynamic loading, often including a blunt or raking impact from various components of the rolling stock or trackbed. Current research is intended to increase understanding of the impact response of fuel tanks under dynamic loading. Utilizing an approach that has been effective in increasing the structural crashworthiness of passenger railcars, improved strategies can be developed that will address the types of loading conditions which have been observed to occur in a collision or derailment event. The improvement strategies developed by this research program can then be applied to alternative fuel tank designs, such as diesel multiple unit (DMU) tanks. This paper describes test requirements for conducting two preliminary tests. These tests are referred to as preliminary because they will be used to evaluate the loading setup and instrumentation planned for the larger series of tests. These preliminary tests will evaluate a blunt impact on the bottom surface of two conventional passenger locomotive fuel tanks. The test articles chosen for the preliminary tests are fuel tanks removed from two retired EMD F-40 locomotives. While these fuel tanks do not reflect the current state of locomotive fuel tank manufacturing or design, they are suitable for means of these tests. Each fuel tank will be mounted to a crash wall and impacted on its bottom face by an impact cart with a rigid impactor at a prescribed velocity. The first set of tests is designed to measure the deformation behavior of the fuel tanks. These tests are planned to result in puncture of the bottom surface of each fuel tank. The preliminary tests are targeted for October 2013 at the Transportation Technology Center (TTC) in Pueblo, Colorado. Following this first series of impact tests, a second set of dynamic impact tests is planned to be conducted. This second set will include both blunt and raking impact conditions on conventional fuel tanks, DMU fuel tanks and fuel tanks incorporating improved strategies for impact protection. Lessons learned during the preliminary two tests will be applied during the second set of tests to improve the performance of those tests. Fuel tank research is being performed to determine strategies for increasing the fuel tank impact resistance to mitigate the threat of a post-collision or post-derailment fire.