Modelers have many scales to select from when building their model railroad layout. Scale refers to the ratio between prototype and model. For example, on an HO Scale or 1:87 model railroad layout, rolling stock, scenery and buildings will be 1/87 the size of the prototype, or real life size.
The most popular model railroad scale today is HO Scale, or 1:87. The smaller scales are N scale (1:160) and Z scale (1:220) and are ideal scales to use where you have a limited amount of space in which to build your layout. On an N scale layout everything would be 1/160 the size of full scale, and on a Z scale layout, things would be 1/220 the size of full scale. The smaller scales call for better vision and hand eye coordination when assembling buildings and working on rolling stock.
The larger model railroad scales are S Scale (1:64), O scale (1:48) and G scale (1:24). Many of the old Lionel trainsets of the 50's and 60's were O scale, and today O scale is still a very popular scale in model railroading. G scale is known as Garden Scale and is extremely popular for outdoor model railroad layouts where it is easy to keep the natural scenery in proportion to the rolling stock.
Garden Railroad Clubs are very popular and have sprouted up across the country in large numbers. Garden railroads are ideal for a husband and wife to share the same hobby. One can tend to the plants and the other the railroad. There is also a new breed of garden centers which make available plants and shrubs sized just right for the G scale Garden Railroads.
Contrary to popular belief, the terms gauge and scale do not mean the same thing. While scale refers to the ratio between model and real life size, gauge refers to the distance measured between the rails. Most scales are modeled using standard gauge track, which in real life, has a rail to rail measurement of 4 feet 8 and a half inches.
Those modelers that model 3' gauge, or narrow gauge railroads use a combination of scales and gauges. For instance, you can model narrow gauge using HO scale. It is called HOn3. The HO refers to the scale and the "n" refers to narrow gauge and the "3" refers to 3' between the rails. The only thing that sets HOn3 apart from HO is that the 10.5mm gauge track it uses is not as wide.
Narrow gauge can also be modeled in S scale, N scale and O scale, and these are called Sn3, Nn3 and On3. What differentiates these scales from their parent scales is the use of narrow gauge track. Rolling stock, buildings and scenery remain unchanged. Modelers can even model 30" gauge track and 2 foot gauge track. Some examples of this are On30 and On2.
There are also even larger scales such as 1:12, 1:8 and 1:4. These would be used on park rides and on live steam layouts where you actually ride on the rolling stock.
