Let me add to the confusion here.

First, let me say that Ed Hawkins has done a great service by placing labels on the body styles of the various offset side hopper cars that allows us to identify one body style from another. However, readers should be cautioned, as I discovered, that the labels Ed uses are not necessarily the labels that the AAR used in identifying these cars. To the point, many cars we would call Alternate Standard were identified as Standard by the AAR.

As Ed points out in his article in RPCYC 1, the AAR Alternate Standard dealt with the use of cast components for the understructure and not the body style. There were two Alternate Standards approved by the AAR, one from Unitcast and one from General Steel Castings. Unitcast did not propose a body style in its Alternate Standard. The body style proposed by General Steel Castings was identical to the AAR Standard, so you could have an Alternate Standard car according to the AAR that would be labeled as Standard by Ed's system. This is not to be critical of Ed's system, but rather to caution readers who trying to reconcile what railroads were calling their equipment and how we label it. Ed makes this same case in his article.

The actual Unitcast Alternate Standard approved by the AAR is shown on page 274 of the 1937 CBC. The body style that Unitcast chose for its twin hopper, which we now call Alternate Standard, is shown on page 244 of the 1940 CBC. However, the AAR did not endorse that body style as Alternate Standard; just the cast understructure.

I went to some length to sort all this out in my book and included lots of pictures in an attempt to make this clear. All of the AAR cars, Standard and Alternate Standard, had tapered or narrow ends. One of the first ways to distinguish these cars is by the design of the narrow end. Enterprise introduced its narrow end design in the twenties. It stepped down to allow room for the grab irons, and the ARA used this design in its original Recommended Practice hopper car in the twenties. This Recommended Practice car (It was never advanced to Standard) used a triple hopper for fifty tons and a quad hopper for seventy tons. A good example of this narrow end design is the B&O W-2 series.

Wine patented its narrow end design in 1929 and granted its use free of charge to the ARA. It tapered from the offset to about 18" from the end post, and from that point the entire side tapered to the end post. The ARA used this design in its Standard hopper cars. However, it also considered the Enterprise design as an acceptable alternative, so it's possible to have an ARA Standard car with the Enterprise narrow end design. You can see what that looked like on page 258, 1940 CBC.

There was a third design in which the taper ran from the last side post to the corner post. This is the design we've labeled the Alternate Standard. I identify it as a Kiesel design in my book.

By using these terms, I think it's easier and a more accurate way to talk about the differences between cars.

Other variations include the arrangements and type of side posts used. The AAR Standard design used lap joints and steel angle side posts with a single row of rivets to join the side sheets together. The distance between the side posts was not uniform. What we call the Alternate Standard used butt joints with pressed steel side posts with external reinforcing plates and two rows of rivets to join the side sheets together. Pressed steel side posts ran from the top of the offset to the top rail. The distance between the side posts was uniform. However, there are pictures of AAR Standard cars with non-uniformly spaced side posts that used butt joints instead of lap joints to join the side sheets.

As others have pointed out, the original AAR Standard design used pressed steel end posts that ran from the end sill to the bottom of the end sheet. These were later replaced by steel angles that ran from the end sill to the top rail.

Then, as Ed points out, there is the angle of the side sill from the last side post to the end post, i.e., whether it's horizontal or climbs to meet the end sill.

Not to mention differences in the form of the top rail, the end sheets, heap shields, door operating mechanisms, and other appliances.

Bottom line is that any simple system to diffentiate these cars breaks down pretty quickly, and it's unlikely that there will ever be any model that would be suitable for all roads. In fact, there were wide variations in the cars in service on single railroads. Both the B&O and the C&O had a number of different versions of these cars. The answer may be that the manufacturer simply numbers the cars in the series that most closely matches the model. Perhaps that, plus some aftermarket parts, e.g., heap shields, door operating mechanisms, to facilitate kitbashing.

Once again, my hats off to Ed Hawkins for the incredible job he did sorting this all out.

Coal roads need lots of hoppers, and its nice having an inexpensive version that permits us to have lots of them at an affordable cost.

Now if someone will just produce the "1905 Common Design."

Bob Karig
Coal Cars: The First Three Hundred Years