Introduction to the wide variety of layouts possible
You have a model railroad and you want to tell a friend about it. What do you say? How do you describe it?
You probably start with scale. That tells what size the trains are. You might mention a railroad name, a geographic location, or an era. This gives a little more information about what you might see on the layout, but it doesn't describe the layout itself.
The layout type or style is analagous to a home style. A realtor mentions a ranch, tudor, bungalow, colonial, Queen Anne or California contemporary, and we have a better idea of what the house looks like. We don't have any idea about the furniture inside, but we have an idea of the house itself.
The type and style of a model railroad layout can refer to the general track arrangement and operating pattern of the layout and the form and construction of the layout benchwork. Some layout types seem to go with particular layout styles and vice versa, and a layout can have a combination of styles. As eyes glaze over, I can only say that everything will become as clear as mud.
Let's start with layout types. Some are described by the layout's general operation. For instance, a switching layout concentrates on industrial spurs and terminal trackage where trains are broken down and the individual cars are delivered to industries for loading and unloading or interchanged with another railroad. Mainline running of trains between cities is not modeled to any great extent or is simulated by staging.
A trolley layout would consist of electric railcars running through downtown streets and into the suburbs with frequent service and short trains.
A branchline layout might model a lightly travelled line as it leaves the mainline and ends at some small town or industry. Only one short train may be running at any time. The mainline connection might be simulated in the manner of a switching layout. Other layout types are described by the track plan. A point to point layout consists of two towns or terminals and the trackage between them. Trackage at either end point might be simulated with staging. A branchline layout could be a point to point layout.
A variation of a point to point layout is a point to loop. The second end point is replaced with a reversing loop. A train returning to its starting point after traveling the length of the railroad is presumed to be a different train. Another variation is to increase the size of the end loop to the maximum possible and reduce the connecting mainline to a minimum creating an out and back layout. In this, the loop is the mainline. Replacing both end points with reversing loops creates a loop to loop layout. A town between the two loops could be the focal point of the layout. In any of these configurations, the end reversing loops might contain staging tracks.
Then there are track plans that are basically circles or ovals of track that are bent, twisted, squashed and smooshed into different shapes. Give one end of an oval a twist and you have a figure eight. Fold in half and you have a twice-around. Or go around three times. Followed to an extreme, with tracks running everywhere, you get the spaghetti-bowl layout. Go back to the oval. Squish the middle together and you have a dogbone. Bend the dogbone in the middle and you have a folded dogbone. Bend the ends of the dogbone in a "C" shape and you have the waterwings. The dogbone can be bent into any number of shapes.
Or should I say, any "letter" of shapes? The waterwings is a "C". You can also shape it into E, F, G, H, I, J, K, L, M, N, O, P, S, T, U, V, W, X, Y, and Z. Doubtless, it could be shaped to represent the other letters, also. A point-to-point layout could be bent into these shapes just as easily.
But now we are talking about the overall shape of the benchwork. This could be considered as the layout's style. One that most people start with is an island. That oval of track on a sheet of plywood is an island layout. You can set it in the middle of the room and view it from all sides.
As it grows to be a larger island, you might add an access hatch in the middle so you can crawl under the layout and pop up to do maintenance on areas you can't reach from the outside. This opens up some new viewing angles that you like, so you enlarge the access hole and then move the controls in to make an operating pit. The layout is now a doughnut.
After a while, your knees get tired from crawling in each time you want to run trains. You give yourself direct access to the operating pit. You now have a walk-in layout.
But only the visitors can wander around and get all the good views. You're stuck on your stool at the control panel. You put your throttle on the end of a long cord and move the controls to a number of smaller panels near the things they control. Eureka!! The walk-around layout.
The layout is still in the middle of the room, with an aisle all around. You discover you walk farther than the train travels, so you switch things around. Give the aisle space to the layout and the layout space to the operators. You've created an around the walls layout. If we allow the layout to extend across the doorway, we create an access problem similar to that of the doughnut. You have to get into the room somehow. Bending all the way over at the waist to get under the layout, this type of access is called a duck-under. Over time, it is called far worse names. These names depend on the length and overhead clearance of the obstruction and the height, age and physical grace of the individual forced to utilize such access. But if we raise the layout in the area blocking access to chest height or better, it becomes a nod-under. If we raise it high enough, it becomes a walk-under. Or we can cheat, and create a lift out section of benchwork to gain access. This, too, will come to be called other names depending on the elegance of the construction, the ease with which it is used, and the consequences of failing to replace it properly. Or we can avoid the situation entirely by combining features of the walk-in layout with the around the wall layout.
We still have a lot of floor space in the middle of the room. Not being into square dancing, you give some space back to the layout. A small bump soon extends across the room, leaving only aisle space between it and the rest of the layout on the far side. It's a peninsula. (DANGER! Peninsulas can grow and multiply to occupy all available space.)
At some point, we run out of floor space, though we still desire more layout space. Your spouse glares at you as you measure the dining room. Retreating to the layout room, you realize the solution has been there all along, above the layout. A SECOND LEVEL!
Welcome to the double deck layout. This utilizes the air space above the first level. As you walk around the layout, you will have two scenes in front of you, one above the other. You use the same aisle space, but the layout itself has double in size. If double decking is still not enough, you don't have to stop at two levels. Go for three. Or more.
A variation of a double deck layout is the mushroom layout. This places two levels such that they are visible from different sides of the benchwork, eliminating the visual confusion of two scenes in view at once.
Our around the walls layout can be contained in a more family friendly version known as a bookshelf layout. As the name implies, the depth is about that of a shelf. A bookshelf layout can continue around the room just like the around the walls layout and can become a multi-level layout, also.
Then there are special considerations that come into play in layout design. If you might have to move, there are ways to take your layout along. A sectional layout can be built such that it can be broken down, moved and reassembled in the same configuration. How often you expect to move the layout will affect the construction details of how the sections join together.
A modular layout is built in segments with standardized track locations and wiring at the ends of each segment. These can be combined in different arrangements. Modules built to the same standards can be combined into larger layouts by clubs locally or even on a national level, dwarfing even the largest home layout.
Intimidated by all of this? Then take the opposite approach and build a tiny layout. Some are able to fit in a brief case. Others resemble a tiered wedding cake in their size. These can be little jewels by being able to concentrate on such a small area.
Remember that a layout is not limited to just one style. There is much overlap in the previous descriptions. There is no inherently right or wrong style. Create and innovate. Combine elements that suit your purpose. Use what will help you get the layout you want.