Unfortunately, they didn't start showing up until the 70's. From my reading, the method of hauling steel in the 50's was in gondolas with wooden cradles or in insulated box cars that kept the steel clean and dry. I will have to go back to my books I was researching in to find the kind that was shipped in box cars. Funny thing about research, you are looking for something else and read about different topics.
Greg Elems