If you are new to the fascinating world of replica trains the terms model train scale and gauge may be confusing, at times they almost seem interchangeable. What follows though, is a simplified explanation of replica trains and their scales and gauges (referring to track size) to help unravel this confusing terminology.
Model trains can lead a child to explore the outermost realms of fantasy or experience the lumbering behemoths of the past, or they can provide a creative outlet for the adult. Part of the allure of these beautiful replicas is that these monster machines are miniaturized to sizes that can fit into a playroom, hobby room or garden area. To that end, certain standards called scales are used to recreate the locomotives as realistically as possible but with a much smaller size. Gauges for replicas refer to the track and the distances separating the load bearing rails. On models, these of course are much smaller and correlate to the scale of the real train. It is impossible to detail every single model train scale because in the beginning each manufacturer and modeler followed their own ideas, only in the last 100 or so years have model scales been more standardized in part due to the efforts of a dedicated few enthusiasts and a major toy train manufacturer. However, what followsare some of the most popular model train scale sizes in use.
HO Scale
This scale is the most popular scale right now in the English-speaking world including the UK. The exact details of the HO scale are that.14 equates to 1 foot of the real train. This shrinks the replica to a size that will allow for detailing of the train itself and yet fit within a room easily. This appeals to both the detail oriented artisan and modeler, as well as the hobbyist who is limited in space. However there is still a lot of disparity in sizing between manufacturers in Europe and the scales may not be precisely.14 to 1 ft even when labeled HO.
N Scale
The N Scale model trains are one of the more popular very small-scale model sizes. The N scale miniaturizes the trains at a scale of 1:148, which means that 148 inches of the train are scaled down to 1” on the model. These tiny replicas are great for modelers who want to create complex railway layouts and scenes but do not have the space to dedicate. On the other hand, the tradeoff is that these tiny trains will display less detail than larger models due to their reduced sizes and they are more costly than the HO models though less expensive than the G scale (often used for outdoor gardens).
G Scale
In popular terminology the G scale model is also known as the garden scale model (though it is not the official term) and these are usually made for outdoor displays. They allow for fine details in the scenery and the model trains but are generally too large for indoor displays. The most popular maker of this scale of replica trains is LGB known as the Lehmann Gross Bahn. The exact scale varies from European to North American manufacturers. Generally, in Europe the G scale is 1:22.5 while in North America it is 1:20.3. Though the difference might seem small, they can become magnified when working with a garden sized layout and consistency should apply throughout the layout.
The 0 Scale
The 0 Scale is most frequently considered a toy train scale and was popularized by the toymaker Lionel. Some modelers however use a 0-scale train size and run it on a replica track.