Little Toy Trains-Z gauge, HO gauge, and OO gauge

In the real world a railway that has a narrower then 1,435 mm 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. Narrow gauge railway's are often duplicated by toy trains.

The smallest gauge toy train available to toy train collectors is the Z gauge. The Z gauge operates on a track that is only 6.5 mm. The Z gauge was introduced by the Marklin Company in 1972, at the Nuremberg's Toy Fair.  The z gauge is so small that a layout can fit inside a standard briefcase. Some Z gauge engines weigh a 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 popular size toy train among toy train collectors is the HO scale trains. The train was first introduced to the market in the middle of the 1930's but it did not enjoy immediate popularity. It wasn't until the 1950's that it started to attract the attention of toy train aficionados. Fans of toy trains started to realize that the the HO's small size allowed them to add even more detail to their layouts.

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.

The typical HO toy train runs on a two rail track that is powered by a direct current. Some collectors have designed HO layouts that have a radius of approximately eighteen inches. The eighteen inch radius models a full scale radius of one hundred and thirty feet. The small radius is so tight that in real life it is only duplicated by streetcars and light rail systems. 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. Some little train enthusiast prefer a flex track that is compatible with a snap together track.

The popularity of the HO gauge toy train makes it easy for collectors to locate models and parts for their little train set. The HO gauge is approximately half the size of the O gauge.

In the United Kingdom the most popular gauge toy train is the OO gauge. The OO gauge was first introduced in 192 by the Bing company. It was called the Table Runway. A 16.5 mm gauge is used for the OO toy train.
