Model trains have been around for some time. During this time the means of powering the locomotives have changed quite a bit. Many of the first trains were clockwork which required winding and had lever to make them stop and go or put them into reverse as well. While not the best way to control them their size helped to make it rather convenient. Eventually model train makers began to produce special tracks that would slow or stop the trains by throwing the levers on the locomotive. This would allow the modeler to set up a station at these points on the tracks. Some of the larger models that were produced could actually run on steam. Either or these types are highly collectible now and much sought after.

Before electric trains became readily accessible to the public due to the lack of public utilities many of the model trains were battery powered. Now that the cost of public utilities are on the rise this method of powering the models is making a grand comeback. Large scale outdoor model trains especially benefit from the use of batteries due to the amount of power they draw and safety concerns that can arise when using power outside. Many model builders still feel like the use of batteries qualifies the trains as a toy but this may eventually change for them as well.

Many of the first model trains to use a powered track ran on a three rail system. This allowed their wheels to sit on the metal track which also had metal sleepers that conducted power. The third rail was a center one that powered a sled that was under the engine. The set up for these first electric model trains was somewhat strange but due to the conductive nature of the metal engines and cars it was meant to be a safer setup for the modeler. Once plastics were to become readily available this adaptation would no longer be necessary. The models also lacked anything resembling true scale standards so some freedom of the imagination was allowed in designing these models.

Eventually model builders became more concerned with accuracy over convenience and soon the model trains were reduced down to a two rail system. One rail was the positive side of the circuit and the other was the negative or ground. Those that decided to stay with the three rail system instead changed the center rail into a series of studs. This allowed for a look that was much closer to the real thing.

Now that scale and accuracy are demanded by modelers the manufacturers have almost perfected the electric train. With a true two rail system they have been able to accurately reproduce scaled down versions of the real thing. Some large scale outdoor use live steam as well as some smaller models that have been modified for this purpose. Gasoline-electric hybrid engines exist as well but tend to be much more expensive than those powered by more standard means.