Model railroading is almost as old as railroading. The first toy trains appeared in Great Britain in the 1940's. Electric toy trains that run on tracks were introduced in the early 20th century. There are quite a few gauges, but the most popular for modelers or as toys are G, O or O27, HO, and N. What’s the difference?
I am an avid railroad fan. My current financial situation keeps me from modeling as much as I would like (serious model railroading is not a hobby for the poor). But I have pretty good knowledge of the various gauges and their advantages for difference purposes. The list in the preceding paragraph goes from largest to smallest of these popular gauges.
First, it’s good to understand the difference between gauge and scale. Gauge actually refers to the distance between the rails of the track. Scale denotes the proportion of the engines, train cars, buildings, etc. to the real objects which they model. This is going to be a fast overview, rather than going into great detail on any one of the choices.
G stands for Garden scale. You can easily recognize this gauge because the rails on the track are about 2 inches apart, and the cars about 3 inches wide and 4 inches high. The actual scale can vary from 1:20 to 1:32. These trains are large and sturdy, and as the name implies are often installed outside and landscaped with real plants. Because of their size trains and accessories are fairly expensive. And for those who desire to incorporate them into a real garden, they are hardly a toy.
One of the best known gauges is O or O27. These are basically the same, but O27 had a third rail in the middle of the track. This gauge is the most popular for toy trains. Lionel was always the leader in this scale of trains and accessories. After a long hiatus, they are back with many new products, making this again affordable for families. In this scale most of the cars are about 2 inches wide and 3 inches tall. It compares to real objects at 1:48. It is fairly easy for children to handle this size train, and parts are large enough to be sturdy enough to withstand controlled play.
HO stand for half O. As such, the scale is not truly half of O, but is 1:87. This is the most popular scale of serious modelers. The rails are about an inch apart and cars just over an inch wide and about 2 inches tall. Parts are too small and delicate for all but the most careful of children, but yet are large enough to support a huge amount of detail. For those who want to model detailed cities, factories, train yards, and do complex train operations, HO is usually the gauge of choice. After years of being almost impossible to find any HO trains, they are now back with many small industries creating accessories for just about any type of setting a modeler could want.
N scale begins to lose a lot of detail. At 1:160 the rails are about ½ inch apart. The cars are about 3/4 inch wide and an inch high. This almost sounds too small to be interesting. Yet it has a very important place in the modeling spectrum. If one wishes to model the long, lonely miles of western tracks, N scale is perfect.
Other, less modeled gauges include S, Sn3, HOn3, Nn3, OO, T and Z. These have their collectors and followers, but in much lower numbers than the others.
Finally, a note about scale is needed. Scale, in model railroading, is a mixture of exact scale replicating, and the art of perception. Model railroading uses something similar to fuzzy logic in computers, only it’s called “selective compression.” For example, in O gauge, an 80-foot passenger car would replicate to 20 inches long. However, most are only 15 inches long. Somehow, an exact replica does not look correct to the eye. In HO gauge, most buildings have their doors and windows exactly to scale, but fewer of them than one would find in a “real” house. To make the buildings exactly to scale makes them look huge. For example, I am building an exact scale model of the barn on my family farm for my model layout. In reality, ours was a rather small barn. On my layout, it looks absolutely huge, and is going to be one of my major industries as a large dairy farm. This is why N scale looks so good for prairie models. The cars are small enough that they are closer to the exact scale as to their length.
If you are considering taking up the increasingly popular hobby of model railroading, this may be of some help to you in deciding in which scale to invest what is certain to become considerable money!