Here’s the thing: I totally get the lack of small, accurate steam models, and I understand and can agree, but the big ones are the ones that SELL. They just do. In the era in which we now live, many “modelers” only have room for one steam engine on their roster, and for a variety of reasons (yes, size does actually matter to some) they want that engine to be a big one. Also, being an articulated, getting a big boy (at least the BLI/MTH/Athearn versions) around 24" radius curves is not much of a challenge as long as one has the horizontal clearances.
It is the big 4-8-4’s and 2-10-4’s, with their monster driver sizes, that have more issues with 24" radius curves.
Also–modern diesels are big indeed. The Genesis 2.0 UP diesel coming from Athearn next year will undoubtedly challenge some layout clearances. I can say that because I know that with larger freight cars, some of my lesser sized modern diesels are actually starting to sideswipe some freight cars on my (recently enlarged and realigned to 30" and 32") horizontal curves. There are a couple areas where I guess I got the track spacing a bit too close for the really big equipment. It’s the huge bulky radiators that stick out from the sides and can hit some longer freight cars including the auto racks and long box cars.
Plus–many of us never thought we would ever see a Big Boy back from the dea