Track pieces for model railways are designated by their ‘gauge’Â which is the distance between the rails. For example, the popular HO scale train has track that is 5/8’Â or 16.5 mm wide, and the scale of the rolling stock is 1:87.1.
When you plan a model railway track layout, you need to be familiar with ‘loading gauge.’Â All it means is the space required on top of and on either side of the track so that the train doesn’t knock over anything. You can test this simply by adding your largest cars to the track and noting their outside dimensions, particularly as they go around curves.
If you have a model train with a pantograph on top, you need to account for the height of the pantograph when it is fully extended. (A pantograph is a metal device on top of a train that collects electricity from overhead lines. They are used on electric trams and electric trains.) You also need to account for any loads that your cars will be carrying. Do they stick out to the sides or above?
As for track layouts, much will depend on what locomotives you want to use and how fast you want the train to go. Generally speaking, the faster you want your train to go, the larger the turning radius you need on curves. Otherwise centrifugal force will cause it to derail. If you want to run locomotives that aren’t pulling cars, you need to adjust the turning radii depending on how powerful that locomotive is. If it is powerful enough to go really fast when it’s by itself, it will also require a larger turning radius to keep from derailing.
You may not give much thought to the gauge of track for your layout, but simply buy track made for the scale, such as HO. That is fine. However, there are narrow gauge purists who set up narrow gauge tracks to mimic some of the narrow gauges that were used in the early days of railroads. It’s just more proof that with model railways, the possibilities are endless!