Minimum-gauge railways have a gauge of most commonly 15 in, 400 mm, 16 in, 18 in, 19 in, 500 mm or 20 in. The notion of minimum-gauge railways was originally developed by estate railways and the French company of Decauville for light railways, trench railways, mining, and farming applications.
Two locomotives of the Whiskey River Railway, an attraction at Little Amerricka in Marshall, Wisconsin