Little Toy Trains
Z Scale, HO Scale, And OO Scale

Contributed by Teresa Bohannon

The standard railway guage, which is 4 feet 8.5 inches (1.435 meters), is based on the wheelspan of Roman carts 2000 years ago.

In the real world, a railway that has a narrower than 1.435 m is called a narrow gauge railway. Narrow gauge railways accommodate smaller radius curves, and are cheaper to build. They are often found in mountainous communities and in communities that don't have enough traffic to justify the expense of building a standard gauge railway. They are also popular in mines, both open-pit and tunnel, and in cane fields.

The smallest gauge toy train available to toy train collectors is Z scale, which operates on a track that is only 6.5 mm wide. The Z gauge was introduced by the Marklin Company in 1972, at the Nuremberg Toy Fair. Z scale is so small that a layout can fit inside a standard briefcase. Some Z scale engines weigh as little as 20 grams. It is very important that a Z gauge track be kept extremely clean, a little spot of dirt can stop the tiny locomotive in its tracks and gum up all the miniature working parts. The most recently manufactured engines are made heavier to improve traction. Older engines are frequently modified by enthusiasts by adding weight inside the tiny engine body.

The most popular size toy train among toy train collectors is HO scale, although N scale is a close second. HO scale trains were first introduced to the market in the middle of the 1930s but they did not enjoy immediate popularity. It wasn't until the 1950s that it started to attract the attention of toy train aficionados. Fans of toy trains started to realize that the HO's small size allowed them to add even more detail to their layouts at lower cost.

The name "HO" stands for "half-O", O scale being the original popular scale.

The name "N" stands for "nine millimeters", which is the distance between the inside edges of the rails

The smallest commercially available scale, Z scale, got its name because Helmut Killian, Märklin's head design engineer, didn't think there would ever be a smaller scale, so he assigned it the last letter of the alphabet.

HO gauge trains are typically less expensive then some of the other size train sets. It is a large enough scale that parents with small children don't have to worry about the pieces getting swallowed.

There are basicaly two styles of HO trains: those that are definitely "toys", in that they are designed to appeal to children, and those that are definitely "models", in that they have a lot of detail and are exact scaled-down reproductions of actual engines, cars, coaches, etc.

The typical HO train runs on a two rail track that is powered by a direct current. The standard HO scale track available has a radius of approximately eighteen inches (45.7 cm). The eighteen inch radius models a full scale radius of one hundred and thirty feet, which is so tight that in real life it is only duplicated by streetcars and light rail systems. In the HO scale models and toys, the couplers are typically mounted on the trucks (called "bogeys" in the UK), rather than on the body of the carriage, so that the tight radius can be achieved during operation. On HO scale models that are exact copies of reality, the couplers are mounted on the body of the carriage; typically these carriages require a larger radius track.

The casual toy train collector generally uses a track that is made out of prefabricated snap-together tracks; the same type of track is often used by exhibitors who move their layout from one show to another. Collectors who have permanent layouts generally prefer to use a track that is constructed of hand laid sections. For longer runs, a flexible track that is compatible with a snap together track is often used.

The popularity of the HO gauge toy train makes it easy for collectors to locate models and parts for their train set.

In the United Kingdom the most popular gauge toy train is the OO gauge. The OO gauge was first introduced in 1920s by the Bing company. It was called the Table Runway. A 16.5 mm gauge is used for the OO toy train.

About the Author:

Teresa Bohannon is the owner and operator of Lady Web.