The PRR Chartiers Branch - Layout Design
04/14/2010
The diagram below shows a scale drawing of the spare bedroom used to house the layout. It measures 9 feet 7 inches (2.92m) from left to right, and 9 feet 11 inches (3.02m) from top to bottom. The window has a curtain that needs to be considered when placing the benchwork. The closet has two bi-fold doors. The drawing shows the doors open and closed, so that I could account for both situations. In the lower right corner is the room's entrance, showing the swing motion of the door.
Layout Design
After measuring the available ten cabinets that I had built in 2003, I re-arranged them on paper to come up with a solution that would make them all fit in the room. From that information, I developed the drawing shown below, which shows the toe-kick ladder frames I need to build. There are two reasons for the toe-kick. One is to allow my toes to go under the cabinets (just like in kitchen cabinets), and, two, is to raise the cabinets above the baseboards in the room. This is necessary, because if I were to include the baseboards, I would come up just 1/4 of an inch short width-wise in the room! In other words, the cabinets wouldn't fit. The toe-kick ladder frame will be made out of 3.5" (8.9cm) strips of plywood glued and screwed together. There will be three of these frames so that they are easy to install and remove. They will be bolted to each other to hold them in place. Mostly for my records, the left ladder frame is 80-3/8 inches (2.04m) long with 13.5 inch (34.3cm) spacers, the center ladder frame is 95 inches (2.41m) long with 12.5 inch (31.8cm) spacers, and the right ladder frame is 72 inches (1.83m) long with 13.5 inch (34.3cm) spacers.
Layout Design
The next diagram shows the ten cabinets laid out in the room. Each cabinet is numbered and they are of a variety of widths. This allowed me to arrange them on paper until they fit in the room. They were not originally built to fit this room, but luck would have it that they do. The cabinets in the upper left and upper right corners are "corner" cabinets, meaning that they were designed to have another cabinet up against their face. The remaining visible front space of those cabinets have a door in them to gain access to the shelves inside. These are great for storing items we don't need very often. Because of the window and the curtains in front of it, I had to move the row of cabinets on the left side away from the wall. Because of that, they will be blocking the door to the cabinet in the upper left corner, which makes the storage space in the cabinet useless. There is a wall power socket behind the cabinet in the lower left (the last one), so the extra space behind there will help with providing power to the layout. The cabinet that is going to wind up in front of the window has a pull-out shelf, which is my workbench. I also have a desk in the room, but that houses my computer, so there's not enough space to do any serious modeling work on it.
Layout Design
The cabinets have a depth of 18 inches (45.7cm). The light brown area will be the space for my layout. The cabinets, as shown above, would yield a model railroad space of 31.5ft2 (2.93 m2). The green areas are possible expansions. The one on the right could be a fold-up board with some storage tracks, to be used when the room's door is closed. The green area on the left could be trackage into the room's closet, which would be removable when the closet's doors need to be closed. Another idea I have is to make trays of storage track that could bring extra cars onto, and take off of, the layout.
Layout Design
After quite some time thinking about various methods for building the actual layout portion of this project, I decided that some key features would need to be integrated into the new design. In no particular order, these were:Using these criteria I have decided to create five individual modules. Their widths are dictated by the current space available for the layout and by the fluorescent light bulbs I will be using. Each module will consist of a base cabinet, backdrop panel, and overhead light cabinet. These module parts will be screwed together so that they can be disassembled when I move, or should I want to integrate lighting into the layout room in the future rather than have it be part of the modules. This would also make it possible to remove the backdrop panel or extend the depth of a module in the future. In the diagram below, the bases of the modules are drawn in light green, and the integrated fluorescent lights are shown in yellow.
Layout Design
The base cabinet of a module looks like the next drawing. It is composed of a solid piece of furniture-grade 3/4" plywood to form the base of the entire module. On top of that are four pieces of 1.5-inch tall plywood strips along the edges. These do two things. First, they make absolutely sure the plywood base sheet stays perfectly flat over its lifetime, and, second, they act as the barriers for the scenery. The scenery will be able to overflow the edges of the base, and the front of the module will have a Masonite front fascia attached to it which will match the edge profile of the scenery.
Layout Design
The lighting needs to be integrated into the modules. What I call the "light bar" is an as-light-as-possible design that holds a fluorescent lightbulb. I will be using the four-foot light bulbs I bought and used during the "P&C Railroad version 4" layout. Those are very bright daylight bulbs. The design below shows a wireframe of the light bar, because if I were to shade it, there would be nothing to see. Most of the pieces are Masonite hardboard to keep the whole thing as light as possible. The front piece represents the front fascia at the top of the layout. It also hides the layout's wiring which will be run above the layout rather than the usual under-the-layout approach. The top and back pieces are also Masonite hardboard. The double endcap pieces are plywood and provide structural integrity. They also serve as filler pieces because most of the modules are wider than the 4-foot length of the lightbulb. The bottom of the light bar, in the center, will be open, of course, for the light to shine through. The diffuser panel will rest on two strips of wood, so that the lightbulb remains accessible. The back of the light bar will be attached to the backdrop support system. The backdrop is simply a number of 15/16th of an inch strips of plywood glued, on their edge, to Masonite backdrop panels (not shown in any diagram).
Layout Design
External Reference:
The next diagram shows the wiring for the lights for each of the modules. The blue blobs are the modules with their lights. I will be using two of the Work Horse 7 electronic ballasts. Each ballast can handle four 40W light bulbs, but there is an upper limit to the distance between the lights and the ballast, so I decided to use two, strategically placed. These are great ballasts, and I highly recommend them. They turn the lights on instantly and are silent. Do a Web search to find the best price for them.
Layout Design
The beauty about DCC is the simplicity of its wiring. I simply run a main bus along the tops of each of the modules, and drop a set of bus feeders down to the modules. Each feeds the track on that module. I can eventually break these up into blocks to be controlled by a Digitrax PM4 and to provide support for signaling. The wiring for the accessories bus (12V supply line) is virtually identical to the diagram below, except that it is powered by a 12-volt wall wart.
Layout Design
This is a rough sketch of the track plan of the layout. It is primarily designed to be a small switching layout.
Layout Design
For this layout I want to have a section of track, about the length of my longest engine, that can function as the programming track. I have had one of these in nearly all of my layouts and they are very handy. You drive the engine onto the track, flip a switch, do the programming of the decoder in the engine, flip the switch back, and drive the engine onto the layout. This section of track can be nearly anywhere, but near the front of the layout is the best so that you can see headlights going on and off to verify the programming took. The track appears as any other track on the layout, but it is electrically isolated from all other track. Some sort of visual cue is needed to mark off where the gap is. The diagram below shows my entire set-up. The Digitrax command station's programming output is connected to the Soundtraxx PTB-100 programming track booster (needed for sound decoders). This programming feed is connected to one pole of the double-pole/double-toggle switch that selects whether the isolated section of track is powered by the standard DCC track power or by the programming feed. I want the comfort of programming the decoder using DecoderPro on my laptop, so the Locobuffer II is used to connect it to Digitrax' Loconet.
Layout Design