Z Scale Trains are the smallest electric trains that are commonly available. Z-Scale Trains are 1/220th of the size of the real-life prototypes. Z Scale Trains are the smallest electric trains that are commonly available. Z-Scale Trains are 1/220th of the size of the real-life prototypes that they are modeled after. The nice thing about this small size is that you can have a layout in a small amount of space -- including inside a briefcase. The most popular manufacturers of Z Scale Trains are Marklin and Micro-Trains, although models and layouts recently released by Tokyo Marui may make them a contender in the future.