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.
 
A few years after World War I, 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 car's design to suit their needs. In other words, each railroad had their own unique version of this flat car.
 
These kits depicts the basic USRA design with modifications to the frame increasing the original loaded weight. They're weighted and come with Red Caboose Bettendorf Friction Bearing trucks.