Modules

Most of my model rail layout is built on small standard modules - an open bottomed box 22.4 inches by 15.25 inches by 3 inches deep. The size of these was predicated on fitting in the cardboard boxes that my stationary supplies arrived in. Serendipitously this means that the module is small enough to work on using my Work Station and, using a scale or 1 cms to 1 inch, I can make a drawing of a module on standard A4 paper (or for my American friends Letter sized paper).

Standard Modules
My standard modules are an open bottomed box with a top deck for my layout and plywood sides made from a sandwich of two 6mm (0.25 inch ply sheets (see Cross Section). These are connected together landscape style (and occasionally portrait style) to form the layout.

Top Deck - I use 1/2 inch (12 mm) thick Insulation Board (UK) (Homasote (US)) cut 14.75 inches by just under 22 inches to fit inside the outer side and end plywood sides. I seal the Insulation Board with thinned gloss paint. Sides and Ends are each made from two strips of 1/4 inch (6 mm ) plywood. For each there is an outer strip 3 inches wide and an inner strip 2.5 inches wide. For the ends, (I got these strips cut from sheets of ply at my local DIY store - I suggest that you get them all cut at the same time to ensure that all are the same width.) I glue these two strips together in 48 inch lengths using PVA glue. and clamp them together while the glue dries. To prevent the sandwich warping, I clamp a length of 2 inch by 1 inch wood on edge along the length. Once several of these ply sandwiches are made up I cut them into 14.75 inch lengths (to fit across the Insulation Board deck) using an electric mitre saw. (The first cut on a 48 inch length is to square up the end, then three sides of 14.75 inches are cut from a 48 inch (1200 mm) length.) Next I drilled holes in the sides as detailed below.

For the sides I use the mitre saw to cut 3 inch wide plywood strips in to lengths very slightly longer than 22.40 inches (the slight oversize can be planed or sanded off once the box is made up - see Assembly later).

Connectors - the modules are joined using M6 (1/4 inch) hexagonal head machine screws. But instead of using a nut to fix these I use Pronged Tee Nuts fitted into a backing strip of wood.. The holes are positioned 1.5 inches up from the bottom of the end strip and 4.0 inches and 11.25 inches in from the back. The Pronged Tees are fitted at the front of the left hand end of the module and the back of the right hand end of the module (to allow the modules to be flipped end to end). Connecting holes in the same position can be drilled in the front and back sides to allow a mix of landscape and portrait modules.

Pronged Tee Blocks: A series of 7mm holes were drilled (using the drill press) 44mm apart in a long strip of 10mm x 44mm wood. Next the strip was cut into 44mm lengths with a hole in the centre of each. A Pronged Tee was pressed into the hole by using a vice. (Initially I thought that I could insert the Pronged Tee buy inserting it, running in a machine screw and tightening to draw the Pronged Tee fully into the block, but found that this tended to split the block - so be careful.)

I used a drill press to drill the holes to ensure that they are perpendicular to the wood and not askew as would be if I had used a hand-held drill. (The cheapest option is to buy a drill stand that fits your electric drill - I got one for less than £10 ($15) but prices vary widely and can be a lot more.)

Positioning: To ensure that the modules would be positioned correctly before assembly I took left-hand end of one module and the right-hand end of the next modules, aligned them and the machine screws through the close fit hole and through the oversized hole into the Pronged Tee in a wood block and tightened. I then loosened and removed on machine screw and Pronged Tee block, put PVA glue on the block and refitted it and the machine screw. After tightening the machine screw, I removed the other block and glued it. This meant that the blocks were positioned perfectly to align the two modules exactly. Once machine screws were tightened, I put the pairs of modules aside for the glue to dry. As it is possible for the positioning of the 6 mm hole to vary slightly between modules, the modules should be identified. I numbered them so that initially the right-hand end of module 1 was aligned with the left-hand end of module 2. When the glue dried on the Pronged Tee blocks module 1 and 2 were disconnected and the right-hand end of module 2 aligned with the left-hand end of module 3 and the Pronged Tee blocks positioned and glued. The process was continued with 3 and 4, 4 and 5 etc.

Assembly: The assembly process is as follows: First I glue and nail one side to one end and repeat. To make sure that the sides and ends are exactly upright and square, after applying glue to the end, I used a jig (from an Angle Bracket) clamped to the end and side together (using C Clamps). Once I had two such assemblies, I placed them around a top deck after running glue in around the inside of the top and down the remaining ends, clamped and nailed. Once the glue was dry I planed off the slight oversize overlaps from the sides. Finally lengths of 2.5 inch wide plywood are cut to length to exactly fit between the ends and glued in place. If necessary you can cut these a tad oversize and plane or sand to length.

Hole Drilling Jig
Although I drilled most of the connector holes on the ends at the same time, I knew that I would have to drill additional holes for connectors and so when I was drilling the connector holes I made up a hole drilling jig. This was made from a 3 inch wide strip of 9mm ply the exact length of the sides (14.75 inch). In this I drilled two 16 mm holes in the right positions for the connecting holes.

Doweling Bushes: Why such oversize holes when the connector holes were 6 mm and 10 mm? This was so I could insert metal doweling bushes that reduced the holes down to 6 mm or 10 mm. By using these bushes I ensured that drilling did not wear away the wood of the jig and enlarge the holes and the bushes helped keep the drill vertical. (You should not confuse doweling bushes with collars. Collars are used to prevent you drilling too deeply. The bushes are metal that fit in a doweling jig. The bushes that I used consisted of a stepped cylinder of metal. Serendipitously, I picked mine up for a few pounds at Lidl!

Cross Section of assembled Hole Drilling Jig showing End Clamps

I completed the jig by marking on it front, back and bottom on both sides and the left hand and right hand sides. Finally on the two sides I marked which hole was which. So, the left hand side had the small (6mm) hole at the back and the large (10mm) hole at the front and the reverse on the right hand side. by marking the jig this way I felt that I would minimise my making a mistake and drilling the wrong holes,

Special Modules
Although most modules are flat topped but several are special. Codling Cove, Losea Esplanade, Losea Pier and Serene Docks have a normal flat section but the beaches and sea dip below this. In contrast, Castle Hill, Serene River and Castle Approach rise above the normal surface.

Track
For most modules, a single track line runs along the back of each module.