In this video, Doug Geiser discusses the engineering behind his Granite Mountain Railway’s three levels, helixes, and the track’s scenic and directional purity. A great aiding factor in creating the three levels of track on Geiser’s layout was building in an unfinished basement. The basement had no walls or ceiling, which meant that there was access to the floor joists. The top level of the layout is suspended from these joists on ¾ inch plywood gusset plates. These plates are filled in with mountains, so they are not visible. The box construction of the top level was bolted into the exposed walls, so there was no worry about dealing with paneling or wiring.
The layout contains three separate helixes or spirals. These can be difficult to make, and must be built very well. Geiser tells Keller how he engineered his helixes. A single helix in his layout is 30 square feet and houses one hundred feet of track. Geiser started with the bottom level and perfected the grade. He then cut small blocks to use as spacers between the levels. There must be enough space for a hand to fit inside, but the space must also be as tight as possible to avoid any problems with the grade of the spiral. He then added the other layers of the helix in thirds until the proper height had been reached.
Detection circuits are essential in a spiral so that operators can make sure where the trains are in the helix. Gesier uses a photodetector with light bulbs on the opposite side spaced 8 feet apart. When the photobeam is broken, an LED light comes on in the dispatcher or front panel to alert the operator of where the train is in the helix.
Scenic and directional purity are important to Geiger in his layout, so each train on the Granite Mountain Railway has its own track and runs in one single direction. The railroad travels from Denver to the West Coast. To remain directionally pure, Geiser made sure that observers would always be looking North so that they could see the East to West bridge route as one long line. Having a unique track for every train allows for scenic purity – the same train is never seen in the same location twice, unless it makes sense for the railroad.