I have acquired several rounded roof 40 ft boxcars in several different roadnames. I like the looks of these cars but can’t recall ever seeing a picture of one. What was the purpose for this design as opposed to the more convention design? Also, how rare or common were these? I have models in PRR, B&O, and NW but that doesn’t necessarily mean they are authentic. Which roads used these?
The roads you have are all authentric but some details may differ such as brake wheels and trucks. Main reason from what I have heard was a one piece side and roof eliminating the seam between the side and the roof.
Hello “je,” The Pennsylvania RR introduced its round-roof, sometimes called “wagon-top,” boxcars in 1932 to increase the volume capacity of its boxcars, and not so incidentally to “encourage” (not to say “force”) other railroads to accept taller boxcars in interchange. In the PRR design the roof and side sheets were not continuous and there was still a seam at the eaves. On some classes of cars the roof extended to the full width of the eaves, while on others there was a setback or ledge between the top of the side and the bottom of the roof. Taller boxcars did become acceptable in interchange, but the PRR round-roof design was not widely adopted. The Norfolk & Western, which until 1964 was controlled by the PRR, did adopt some of the Pennsy boxcar designs. The Seaboard Air Line purchased or built similar cars that weren’t exactly the same. The Baltimore & Ohio’s wagon-top boxcars were completely different. The B&O began experimenting with its design in 1934, first using it to put new steel superstructures on steel underframes salvaged from old wooden boxcars. The B&O did use a continuous side and roof sheet, supported on side posts that curved in at the top to serve as the carlines or roof supports. The appearance was somewhat reminiscent of the canvas top of the old Conestoga wagons, hence the term wagon-top. The B&O was attempting to achieve a lighter carbody than conventional boxcars of the time, and was most successful with the wagon-tops it began building as completely new cars in 1937. However, the B&O car proved marginally heavier than the AAR-standard boxcar design adopted in the same year. Thus while the B&O wagon-tops were successful enough to be built by thousands and remain in service into the 1960s, the design wasn’t copied by any other railroads or carbuilders. So long, Andy
Early in the 20th century the Pennsy complained to the SP that its new, tall automobile box cars wouldn’t fit in some tunnels. Maybe the rounded-roof was Pennsy’s solution to increase capacity while providing better tunnel clearance.
Mark
As I recall NP liked round-roof boxcars going back to the wooden boxcar era.
There’s a difference between the old radial roofs, which were continuously curved to a large radius (common on the Northern Pacific but used by many other roads as well) and the “round-roof” or “wagon-top” cars that had rounded corners at the eaves and flatter roofs toward the center. The NP had some of the round-roofs too, which it acquired second-hand from the Detroit, Toledo & Ironton, another road controlled at one time by the PRR. So long, Andy