Scale, which tells you the ratio of your model train compared with a real one. An O scale model train is 1:48, so 1 inch on the model equals 48 inches on a real train.

Before HO scale became the standard for model railroading, O scale was the dominant size, with a ratio of 1:48. However, in the early 20th century, a growing demand for more compact model trains ...

Known as “The Train Lady,” North Barrington resident Elaine Silets is the owner and operator of the Harvey M. Silets Memorial O-Scale Model Railroad Museum, which is named after her late husband.