Narrow-gauge railway

The No. 9 - Prince of Wales locomotive that is used on the Vale of Rheidol narrow-gauge railway in Wales.

A narrow-gauge railway (also called a narrow-gauge railroad in the United States) is a railway with a track gauge that is narrower than the usual 1,435 mm (4 ft 8 1⁄2 in).

Most narrow-gauge railways are between 600 mm (1 ft 11 5⁄8 in) and 1,067 mm (3 ft 6 in) wide.

In some countries around the world, including Japan, Indonesia, South Africa, New Zealand, Malaysia, Taiwan and some states of Australia, a narrow-gauge is the standard railway gauge.