Sscale Model Railroading

An explanation of the difference between scale and gauge in model railroading, an area of common confusion with beginners to the hobby.

One of the areas of the hobby of model railroading that confuses the most people, is the whole topic of scale vs gauge. People generally aren't too particular about how they use these terms, and even experienced hobbyists often use them incorrectly, thus confusing any beginners who are listening. This article will attempt to simplify and clarify the two very different concepts of Scale and Gauge.

Let's start with scale. The scale of any model, be it a train, ship, human figure, or doll house, is nothing more than a mathematical representation of the ratio of that model to the real object it represents. For instance, if you were to make a life size model of a human head out of clay, it would be said to be a 1:1 scale model. If it were only half the size of the real head, then it would be a 1:2 model. Sometimes these ratios are expressed as fractions (i.e. 1:1 would be written 1/1, 1:2 would be 1/2, etc.)

Normally, with model trains, people don't model in 1:1 scale, as they just can't fit them in their basement! Modelers do use this term sometimes, however. When you hear a model railroader say that "Frank works in 1:1 scale", then this is their way of saying that Frank works on a real railway, and "plays" with real trains. So scale represents the ratio between the size of the original object, and the size of the model that is made to represent it. This is important: Scale doesn't necessarily have ANYTHING to do with how wide the model rails are set apart! This statement may seem strange, but you'll see what I mean. There are many different scales that are used for model railroad models. The most popular scale is 1:87 (or 1/87 of life size), which is commonly known as "HO Scale". Next most popular is 1: 160 scale, which is called "N Scale". Other common scales are "Z Scale" (1:220), "S Scale" (1:64), and "O Scale (1:48).

If you go into a store, or look at a magazine, you will see something referred to as "G Scale". This is where the whole area of scale vs gauge gets really complicated. G Scale is commonly used by modelers to refer to a whole family of different scales, all of which share a common Track Gauge. By "Track Gauge", we are referring to the distance between the inside edges of the two rails which make up the track. It doesn't matter if we're talking about a real railroad's track, or a piece of model railroad track, the distance between the rails is the "Gauge" of that track. In real railroads, the track gauge varied widely. Some railroads used track that was seven feet apart, some used four feet, eight and a half inches (referred to as "Standard Gauge"), some were one meter, some were three feet, some were two feet, etc., etc., etc. You could build a railway to any gauge you wanted, and people did! Gauges less than Standard Gauge were called "Narrow Gauge". Larger than Standard Gauge railroads were referred to as "Broad Gauge". Think about it: If a railroad was built to operate on two foot narrow gauge track, then it was still 100% percent life size, wasn't it? The fact that the tracks were narrower, and the train was smaller to compensate, didn't change the fact that the engines and cars were full size for that gauge. It's the same for models!

An HO scale model that is built to represent a narrow gauge prototype, and which runs on track which is narrower than standard gauge HO track, is still HO scale! It's still 1:87 of the original prototype, however big that was. To handle this confusing aspect of scale, additional information is added to the name of the scale, to let people know that it does not represent a Standard Gauge model. In the case of an HO model of a Three-Foot Gauge locomotive, the scale would be written as HOn3' (HO scale, Narrow Gauge, 3' Gauge Track). Thus, you will see such notations as HOn2', HOn30", Nn3', etc. The first part states the scale, the second part indicates narrow gauge, and the third part represents the gauge of the full size track that the original prototype ran on.

Now back to G "Scale". G Scale is not really a scale, per se, at least not in common usage. "G Scale" is a copyrighted name that was introduced by a company called LGB, to denote their line of Garden sized model trains. The "G", as I'm sure you've guessed, stands for "Garden". These trains generally represented One Meter Gauge prototype engines and cars, and were built to a scale of approximately 1:22.5 . In this scale, the tracks worked out to 45mm apart in model form. So LGB built an entire line of track and switches with a track gauge of 45mm. That's when other manufacturers jumped in, and created models designed to run on this 45mm track, but which were NOT built to 1:22.5 scale. Some of them built models representing Three Foot Gauge prototypes, some built models of Standard Gauge prototypes, and some just made up their own scale which didn't represent any particular prototype. But most modelers refer to ALL of these models as "G Scale" models, which is technically incorrect.

For instance, if you want to make a model that represents a Standard Gauge (4', 8-1/2") locomotive or car, and you want to make it run on LGB's 45mm track, then you need to build the model to a scale of 1:32. The scale is totally different from LGB's, but it still runs on their track. Some models of standard gauge locomotives have been built to a scale to 1:29, which makes the model larger and more impressive, but is technically the wrong scale for LGB track, a point which has a lot of modelers ticked off, as they would have preferred it to be accurate and to scale.

No wonder modelers are confused! I hope this has clarified this area for you a little bit. To sum it up, "Gauge" really only means the distance between the rails, period! No matter how incorrectly people use it, that's what it actually means. Scale, on the other hand, indicates the ratio between the real object, and the model built to represent it. Keep those two facts in mind, and you'll be able to figure it out! Happy Railroading!

© High Speed Ventures 2011