Wheels -- answering my own question

[dknelson]

Long ago I posed a question about what size wheel to put under my Model Die Casting modern Thrall coal gons -- 33" or 36". I had bought a set of cars used and the prior owner, who had done a really nice paint and decal job, mixed em up -- some had 33 inch wheels, some 36 inch (at least each car was consistent). I think the original kit from MDC came with 33 inch wheels.
I finally found the answer and it is another reminder that sometimes, in an effort to keep things simple, some assumptions are made that are not correct. A case in point: Kadee makes nice replacement wheels and sells the 33" as "freight" and 36" as "Passenger." But the 1966 Car and Locomotive Cyclopedia makes this clear: 33 inch was standard for years but in 1960 the AAR ruled that cars over 70 ton capacity needed 36 inch wheels, and over 120 tons needed 38 inch wheels, with 28 inch wheels used for some low deck intermodal flat cars. (the Cyclopedia also points out that some passenger cars did have 33 inch wheels too). If you don't have a Cyclopedia from around your era -- and they are pricey I do not deny it -- you are missing out on an amazing source of information, plans, photos, and interesting ads.
The Cyc. answered my question and I hope this info helps others (The Thrall coal gons are 100 ton cars so they need 36 inch wheels -- I assume the coupler height will need adjusting as a result, and maybe it is better to live with the wrong wheel if changing the coupler height is too difficult).

By the way this is changing the subject but another example of how a manufacturer can inadvertently mislead the beginner by mis-stating the facts: for years Athearn and other makes sold Pennsylvania Railroad locos marking the Tuscan Red engines as passenger, and Brunswick Green (almost black) as freight. This was not always the case, many, perhaps most, passenger engines were Green/Black. Relatively few were red. This depended partly on what series of engine is involved. Unless you lived along the PRR you would not know this. I figured the manufacturers knew what they were talking about and it took years of arguing with more knowledgable Pennsy fans before I realized how dead wrong I was
Dave Nelson