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Peter's Model Railroading | The Layout | Stops | The Hazel Mine Complex | Hazel Mine Tipple
Module Design

This module will measure 2 feet wide by 4 feet deep. The width is restricted by what I can easily carry. The depth is restricted by wanting to model the entire Hazel Mine tipple, as well as the mine's entrance across the Chartiers creek. The portion of the Sanborn map shows most of what I will be modeling in this individual module. I rotated this diagram, but the front of the layout will be the right-hand side of the diagram. The tipple will sit very close to the (right-hand side) edge of the module, because the power station building, which supported the operation, sat right next to the tipple, so there cannot be too much of a gap between this module and the next one over (to the right, or "above" as the diagram is oriented here). The five tracks covered by the tipple are straight (perpendicular to the tipple), and period photos show no turnouts in this modeled area. The tipple building is the larger gray rectangle, and the incline from the mine entrance to the tipple is the smaller gray rectangle. The mine entrance is on the left-hand side of the diagram, which will be the backside of my module. The incline goes over the Chartiers creek.

The rest of this page contains a series of CAD drawings that show the make-up of the construction of the module. The front panel is 24" wide and 4" tall. The bottom will make the entire module be 48" deep (the bottom sheet actually measures 23-5/8" x 47-5/8"). It will be inset into the module's vertical pieces, so that the exterior is as clean-looking as possible. This means the bottom sheet has to be cut to precision to get it to fit nicely. Most modules will leave the bottom open, but I see two problems with that approach for my situation. One is that the module starts acting like a speaker, amplifying the sound of the wheels running on the tracks. By enclosing it, I might be able to put some sort of insulation in it to minimize the noise. Second, having a flat, solid bottom allows me to put the module on a surface, regardless of how that surface is composed (table, cabinets, boards, boxes, etc.), without the risk of damaging the bottoms of the vertical pieces. Since I don't use electricity on the rails, and move the turnouts on the layout manually, there is no need for having access to the underside of the layout. If I later on need to add a sound module or feeding wires for lights, I can retrofit them easily enough. However, my ideal goal is to build a layout that does not require needing to be plugged into the house's wall power socket.

The back wall is identical to the front one. Depending on how the Chartiers creek will flow in this area, I may need to trim it here and there.

The side wall fits in between the front and back panel, and up against the side of the bottom panel. So, it is a piece that is 4" x 47-5/8".

The other side wall is, of course, the same shape and size. They will be custom-trimmed as necessary to correctly model the Chartiers creek.

To be able to transport this skinny but long module, I decided to add some grab handles to the sides. The idea is to put your stomach against the front panel and, holding your elbows at your sides, slide your hands into the open slots, allowing for easy access, even in tight (horizontal) spaces. The module should be light enough to support that, and, by designing this in from the beginning, I can make sure to design the interior structure strong enough around these grab handles for extra support. Also, the module can be carried sideways by putting one hand in the slot and the other hand under the rear of the module (that's another reason for why the handle slots aren't in the center of the module, to help balance it while carrying it.

Next, we need to develop the interior bracing. These are slats that measure 23-5/8" long and 3-5/8" tall. After placing them 4 inches apart, I realized that it would take more than one sheet to get that many slats. So, I changed them to be 5" apart, but then they didn't fall in the right spots for the handles. So, I decided to space them 6" apart and move the handles up the side panels by 4 inches. This shows the value of using a CAD program, because you can think through these steps before actually making any cuts. One of the things I wanted to do is to make sure there was enough bracing right by the handles.

Speaking of the handles... I added three layers of small pieces of Gatorfoam board to each of the openings for extra support. These are shown in red in this diagram. They measure 5-7/8" long x 4-7/16" tall.

To complete the interior bracing design, I added these other pieces. I have not yet decided if I am going to cut a bunch of individual pieces (a lot of work and a lot of gluing time), or make these slats with half-lap slots in them that will fold together as shown here (requires precise cutting, slow-setting glue, but would be stronger). I may also drill some holes in these slats to make them even lighter, and also to allow for adding insulation, if so desired.

Next up is the creek in the back of the module. The cut-out of the framework will be square, but the actual creek will have a more natural flow to it (which is hard to model in a CAD program) to resemble the creek's banks. The banks will be added using the conventional scenery-making techniques. The cut-out space represents the entire area that the Chartiers creek takes up on this module. It is two inches deep, as locals have reported that the water level in the creek is typically around ten feet below the ground level (10 feet = 120 inches = 1-7/8" in S-scale). For completeness, note that a sheet of 3/16" Gatorfoam board will be placed on top of the grid to form the bottom of the water surface of the creek, and that the top ground layer of the module will have 1/2" ceiling tile added. So, the final height difference will be 2-5/16", which is 7/16" more than the 10 feet requirement, but that gives me some room for adding layers of epoxy to represent water and waves. I want to document all these measurements, as they must be matched with any future modules so that the water level is equal between them.

I realized that there wasn't much support for the actual corners with this design, so I decided to add some interior blocks. I am going to make these out of two strips of 3/4" plywood, glued together to form a 1-1/2" square block. They are about 3-1/4" tall, to clear the top sheets. However, they will also have a 1/4" hole drilled into their centers on the bottom, so that, should I want to do so in the future, I can easily install a 1/4" bolt to act as leveling feet. It is much easier to drill that into the block of wood while it is out in the open, than when it is installed in the module.

The final step in the design of the core module is to add the top ground layers (green) and the water layer (blue) to the design. This should, then, approximate the final look of the base of the module. Not included in this design is that I will also add a 1/2" sheet of ceiling tile to the front green layer in the actual construction. This helps to absorb train sounds, as well as allow for modeling dips and ditches in the scenery (1/2" in S is equal to a scale 32").

I use OpenSCAD for the 3D CAD program, whose screen captures you see on this page. Should you wish to copy this design for your own use, I have decided to share my data file to use as you please (right-click to save it to disk, or click it to view the source code).
(external link: OpenSCAD)