High level plan

As I said earlier, I make no bones about the fact that I'm going to be heavily influenced in many ways by John Olson's Jerome & Southwestern railroad. I bought the Building an HO Model Railroad With Personality book way back in the mid-80s (I have the second printing, which was dated 1985. I probably bought it that year, or 1986 at the latest.) This is the book that collects the Model Railroader articles in which it ran as a project railroad from back in 1981-82 or so. Obviously some of the techniques in terms of benchwork, scenery and especially wiring are out of date now, and better (or at least easier) techniques now exist, but the truth is that you can't argue with the results. Even though the J&SW (and it's BA&W little switching 2x8 expansion) was a small railroad, the stereotypical 4x8 ft. plywood beginners pike, in fact, the reality is that it looks better than most railroads many times its size. 

A couple of small observations, and then my own high level plan:

• Although it's only a 4x8 (with a 2x6 expansion) railroad, with a somewhat complex track plan for being a stereotypical loop, vertical scenic elements help divide it into diorama-like sections that make it feel much larger. In general, I'd say that the sections are the foreground/Clarkdale section, the Apache Gorge, the Dos Hermanos tank town, and the back Jerome/Cleopatra Hill/Furlow's Folly mine. The Back Alley & Wharf expansion tends to be its own section.
• In order to pull that off, the pike uses extremely small structures. The Atlas passenger station kit (706) with the covered dock removed and the AHM Railroad express station (5831), not large buildings in an absolute sense, are by far the largest structures on the main railroad. In fact, they're at least twice as big as every other structure on the pike, with the possible exception of the Prairie Fire Inn (Train miniature saloon (7054). That means that the majority of the other buildings are little more than sheds, shacks, shanties and other tiny buildings. The BA&W expansion also has two or three buildings about the size of the largest buildings, but as that's an urban section, it makes more sense. This may seem strange, but anything larger would dwarf what's going on with the scenery and trains, so it's actually quite necessary to keep it minimal and tiny, yet with character. Many of these smaller structures were either parts of another kit, or group, but used individually in a different context.
• At the same time, trains and stock need to be small. I rarely see a train with more than about 5-6 cars, and often only 3-4. The motive power is limited to small switchers and geared locomotives, mostly; stuff like a tiny 0-4-0, a 2-truck Heisler, an SW1500 diesel, etc. Rolling stock is all 40' or even less, given that 26' ore cars seem to be one of its main standbys. All of these helps ensure that no thing dwarfs the context that it's in.
• Although it's done as a classic loop on a 4x8 diagram, there's some operational complexity by building:
• passing sidings on both long edges
• a short spur within the loop at Clarkdale
• a long spur that crosses the entire layout diagonally at elevation, shaped like a bent Y.
• a reverse looping spur that allows you to change directions.
• the more yard-like structure to the BA&W expansion that is a more "switching layout" design.
• Most of the questions that people ask in the little side-bars of Model Railroading are superfluous if not absurd with regards to this railroad. What's the prototype? Well, kinda sorta there is one, but its more in general flavor and a highly distilled experience than in any specific detail. What's the minimum curve radius? I dunno. It's never reported. Probably 18", but I wouldn't swear to that. What's the maximum percentage grade? I dunno. It goes from 0 to 5½" on the diagonal spur. Whatever that percentage is. It's gotta be pretty steep to be able to cross over the tracks only a foot or so from starting its rise, though. Anyway, it goes on. What exactly do people think that kind of detail is so important for, anyway? One notable thing: I have no idea when this model railroad is supposed to take place. It has an old Roundhouse Climax and a 4-4-0 on the motive power list, but it also has a SW1500. They made the 4-4-0s back in the 1860s and the SW1500 in the 1960s. Otherwise, it has a kind of 30s-40s feel to the place in general. But again, there's  nothing definitive, and there's no reason for there to be, either. In real life, the mine in Jerome that is the main industry that this railroad serves, shut down in 1951. None of that makes any difference whatsoever to the J&SW appeal.
• On the other hand, for a 4x8 railroad, this doesn't dumb things down. It assumes you want to make a good-looking railroad with some advanced techniques. Compared to other books that I had in the 80s that were similar in scope, like Linn Westcott's HO Railroad That Grows, this is a much better looking, more "professional" looking railroad that doesn't assume that you're just a dumb beginner who can't figure out how to do tricky things like use flextrack or under the benchwork gorges, etc. It also has a much more coherent and strong theme, unlike the "uh... maybe adding a little hill right here would be cool, yeah, that's the next part of the project," ad hoc feel of Westcott's book.

Anyway, I've got more than I can (and no doubt will in the future) say about Olson's book and his railroad, but I'll be up front; my plan is to start with a pseudo-copy cat railroad, using the same track plan and similar theming, including the BA&W as an original piece of it rather than as an add-on, but then I'll add other modules in the form of two (or possibly even three) more 4x8 loops, connected by 2xn bridges. The BA&W copy will in fact, be 2x8 rather than 2x6, and that extra two feet will mostly be for adding scenery and allowing for the two straight lines to gradually bend so that they can connect to the next 4x8 loop on that side the way that they do on the other side. But let's not get too far ahead of ourselves; the main point will be to start with the J&SW and the BA&W and then add the other parts, which will be unique, since John Olson didn't ever build anything like that, later after the original is done.

Now, first off, a lot of the kits that Olson used aren't in print anymore (although another large chunk of them still are.) And as much as I admire the Arizona railroading approach, the Ruritanian approach doesn't have an Arizona, and as an ethnic Texan myself, I find the idea of a Trans-Pecos desert more appealing. How will this change my approach?

• I'll obviously be renaming the towns. Instead of Clarksdale as the main town and Dos Hermanos as a tiny, rundown tank town, I'll have Jefferson and Davis, respectively. 
• The Walthers backdrops won't work, because they have saguaro cacti all over them. The Trans-Pecos has prickly pear and other cactus, but not saguaros. I'd actually prefer to take my own photos of the Grapevine Hills and the Chisos Mountains in Big Bend National Park as well as Sawtooth Mountain in the Davis Mountains to serve as my backdrops. That gives me an excuse to drive around for a few days out in West Texas, which is always fun in it's own right anyway.
• Although copper mining isn't an important industry in the Trans-Pecos part of Texas, it can be in the Ruritanian southwest, so I'll maintain the copper mine at the end of the long, elevated spur. I really like the visual of the spindly little mine up in the hills anyway. But other than that, I'm going to put a tiny little stockyard in Jefferson, and make sure that my pike has plenty of ore cars and stock cars to serve these two most important industries on the railroad.
• I'll need to make sure that I can cover a few iconic plants of the area to give the correct vibe; some prickly pear cactuses, some dagger yuccas, and the ubiquitous mesquite tree. Other than that, I'll probably also need considerably more tufted dry grasses than Olson uses, as it's pretty iconic to the region, especially up near Fort Davis. Woodland Scenics clump foliage, fine-leaf foliage and bushes can provide credible creosote bushes too.
• The "far side" of the railroad including a big tunnel with switches in it is tricky. I think I'm actually going to make it have an opening showing a mine interior, so I can go back around the backdrop to check on trains back there if I need to.
• I'm going to use thin styrene rather than homasote for the backdrops. And homabed roadbed exists, so you don't have to DIY your homasote into a roadbed. (On second thought, it looks like the homabed supplier went out of business in 2020. I guess I can use cork, or something. Heck, with foam insulation board, I probably don't need any roadbed at all except for the height. And you can get ¼" thick foam insulation to cut if you want to.)
• The BA&W stuff will have the most severe retheming. There'll be a small town of frontier-like buildings on the left hand side, and the tracks with the switches and spurs will serve like a small yard for train building as well as coaling, ash-dumping, etc. and other things that steam railroads need. There won't be any coaling towers; that's way too big of a building; more like small coal depots and guys with shovels and wheelbarrows, or at most a crane. Some sample images below, from Faller. Vollmer also makes similar sets.
• The right side of the BA&W won't be a harbor, but rather a bayou, with a little village, partly on a low wharf or dock. It'll give me a chance to really try out some interesting new scenery, like twisted live oaks draped in Spanish moss and bald cypresses with their "knees" poking out of the water. Maybe I'll even have a little mini diorama of some inspectors busting up a cult meeting around an idol as an in-joke about Call of Cthulhu. This will segue, eventually, into the pseudo-Appalachian coal-mining region, which will be the next 4x8 to get developed. But let's not get ahead of ourselves.

Anyway, beyond that, the Appalachian 4x8 will be connected via a 2xsomething bridge to the Rocky Mountain 4x8, and that bridge will contain a massive gorge with a bridge or two crossing it high above a below the benchwork canyon. But I have only vague plans for those sections of the railroad as it expands...