HISTORY During World War I the United States Railroad Administration designed a number of cars including two box cars, hoppers, a gondola, tank car, refrigerator car, caboose, passenger cars and a flat car. The box cars and a few of the other designs were built while other designs were set aside, the flat being one set aside. Within a few years after the war was over railroads began replacing older equipment and looking for designs that would meet their needs. A number of railroads adopted the USRA design with very few changes such as underframe structural changes allowing the load weight to be increased. Other roads shortened, lengthened, narrowed or widened the cars design to suit their needs. Because of these changes, researching what roads had this car would be nearly impossible.