I think it all boiled down to price when it came to anthracite sizes being mixed. For home heating, the larger the size the more it cost. My folks always ordered a mix of sizes. Think the larger stuff kept the finer pieces from falling through the grates.
Been studying the anthracite industry for years. A really great source of info to help get some idea of coal movements is to study the carloads received from other lines. For most easter roads this is broken down into anthracite and bituminous. Usually the number of cars laoded on line is given.
I agree that very few C&O cars were seen in the northeast, or at least that I can recall. On the D&H moving north out of Wilkes-Barre and bound for Canada and New England there was a very large volume of bituminous coal along with the anthracite. For all intents, The D&H was an extension of the PRR to New England and Canada. Do remember seeing N&W cars. Even recall seeing some of those Seely type SOU composites with outside chains holding the bottom doors; also northbound on the D&H. Almost all the loco coal used on the DL&W and D&H arrived in PRR hoppers since these "anthracite" roads burned very little anthracite after about WW1.
During steam years roughly 25% of all coal produced was used by the railroads so much of what was moving to New England was loco fuel. So a model railroad with coaling facilities should have some logic as to where that coal orginated.
Railroads could never compete where a water route was available. One of the most amazing examples of this was where the PRR at Sodus Point NY loaded bituminous coal into lake boats to transport it to a power plant at Oswego...a distance of only 40 miles!
All very interesting...and not a lot of documentation available!
