So, how does one capture a 23-mile branch line, with a couple of branches of its own, and interchanges with other railroads, in a small space in S-scale? Especially when the goal is no selective-compression?
My high-level, overall plan is to build a number of stand-alone dioramas. This allows me to go through all the model railroading steps of layout construction repeatedly (which I enjoy), such as building the framework, sculpting the scenery base, laying the track, building the structures, and detailing the scenery. Also, by focusing on just one such diorama, I can make it as detailed as I want, and take my time. It will provide a great sense of accomplishment.
Over the years of model railroading I have learned what I personally enjoy doing, and what is not so much of interest to me. I enjoy all model railroading styles that others engage in, but for me, personally, what I like to engage in is "building". I enjoy operating on other people's layouts (in moderation), but I am not at all interested in holding operating sessions on my layouts; seems way too much like "work" to me. I enjoy detailing things and making things as accurate, or at least as believable, as possible. So, the idea of completing one large layout and then operating it is not my end goal. I, essentially, want to just build a new layout. This explains why I have built so many over the years. This new approach documented here is a perfect fit, for me.
When I have the space to do so, the plan is to then take these stand-alone dioramas and connect them with some, possibly hidden, flextrack, to form a more conventional model railroad layout.
A simplified version of this concept is shown in this diagram. The green rectangles represent dioramas (which can consist of one or more modules or sections). In this concept drawing, they are placed in a corner, and the corner is occupied by a loop of track or an over/under helix. The idea here is that a train leaves one scene (or "stage") and doesn't re-appear into the other scene until some time has passed. If the trains are shorter than the loop, a crossing track can be used; if they are longer than the loop, then a one-turn helix can be employed to avoid the engine hitting the rear of the train. Of course, this concept can be extended to allow for a multi-level helix, or to make the loop into a storage/staging yard. This corner loop would be hidden from the normal operating viewpoints, but would be accessible via the back of the layout.
And, of course, stand-alone dioramas can be connected with just pieces of flextrack when they are placed next to each other in line. This allows me the freedom to model any scene along the branch line that I feel like building, without having to be concerned about it connecting to the next scene over.
Building modules or sections makes the whole thing easy to re-arrange, or even move. The sections can be whatever size they need to be to capture the scene I intend to model.
The plan is to keep every single module I build over time. I am done with taking layouts to the dump. So, this is my permanent and last layout, which is going to take me decades to build, and will move with me wherever I go.