Prior to their more recent "Ready-To-Run" state, these models were available in kit form.
With the onset of World War I, the United States Railroad Administration (USRA) was faced with the possible shortage of raw materials to construct desperately-needed rolling stock. In an effort to decrease construction time, provide a cost savings and simplify repair and parts supply, a group of seven standard freight car designs were created that could be built in large quantities. Over 20,000 composite gondolas were constructed during the war time.