Just like when building a house, you need a firm foundation when you are building your model railroad layout. In model railroading our “foundation” is the benchwork for the layout. As you can see in the photo from Scott Lister’s Greenville and Northern Railroad, he has built a sturdy foundation for his award winning house under construction model, but what you don’t see in the photo is the sturdy benchwork the model is sitting on. When we visit model railroads many times we forget to check out the underside of the layout and learn how the modeler built their benchwork.
Scott designed his layout as an “island” type, filling the center of the layout room without it being attached to any walls. The benefits to this type of layout design is that you can walk around his layout while following your train and in many places have access to it from both sides. Because you don’t get any structural support or stability from the walls with this type of layout the benchwork needs to be well designed and constructed. The flowing shape of Scott’s layout also offers stability to the entire assembly as the sections are connected together around as they go around the room.
Recently I went back to visit Scott, and this time I asked him more about his layout construction methods and checked out how he built the benchwork. Scott used an “L” girder type of construction method and built the layout in sections. This way if he ever needed to change something he could build another module or modify the existing one without affecting the rest of his layout. The L girder benchwork allows for scenery contours above and below the track, because the track is placed on plywood cut to the track profile and attached to risers. The scenery is then filled in around the track profile board. This style of layout construction is often referred to as “cookie cutter” as the track design is cut out of a large sheet of plywood, allowing for a few scale feet along the right-of-way.
For my layout I chose to build a conventional wood frame and top it with 2” of extruded foam. The framing was constructed with 1X4 or 1X6 lumber and was framed much like a wood stud wall in your house, with cross braces set on 16” centers. The framework was constructed in my garage to keep the dust out of my finished train room. Once it was done, with holes pre-drilled for the wires, I carried it into the train room and attached it to the walls. On the peninsula I used 1X6 lumber to prevent any sagging since I only wanted legs on one end and the span was 7’ from the wall where it attached to the end of the peninsula. One complaint I have heard about this type of construction with a 2” extruded foam top is that you can have some drumming noise from the trains as they move on the layout. With the slow speeds I have on my layout this really has not been an issue. One way to mitigate this is to use a thin sheet of plywood on top of the framing before you place the 2” extruded foam on top of it, this cuts down on the sound transmission through the foam.
As part of the benchwork foundation, you need to consider any depressed areas for scenery. In my river and stream areas, I dropped the benchwork framing down a few inches to give me more depth for the water features and bridges. Foam can easily be stacked and carved for terrain features that are above the base level, but those that drop down need to be planned for and constructed when you are building the benchwork.
Other methods of benchwork construction can be used for your layout, it is all up to you as to what you prefer. A hollow core door is a great option for a small shelf style switching layout. It gives you a sturdy flat foundation and is easily placed on shelf brackets or a book case. For those layouts that climb mountain grades a spline style of construction can be the best option. This type of benchwork gives you smooth sweeping curves and changes in track elevation. No matter what you choose, time spent building good quality benchwork will pay off with years of smooth reliable operations. Don’t be in a rush when building the benchwork, take your time and build a sturdy foundation.
The couple on the front porch of a house on Scott Lister's layout is glad to know they are on a firm foundation.
Until next time, stay safe and keep model railroading.