Minimum-gauge railway
(重定向自Minimum gauge)

Minimum gauge railways have a gauge of most commonly 15 in (381 mm), 400 mm (15 ⁄4 in), 16 in (406 mm), 18 in (457 mm), 500 mm (19 ⁄4 in) or 20 in (508 mm). The notion of minimum gauge railways was originally developed by estate railways and by the French company of Decauville for industrial railways.