A narrow-gauge railway (spoken) is a railway with a gauge width less than standard; the rolling stock of such roads is incompatible with normal-gauge roads in a number of parameters (that is, technical problems are not limited to rearranging bogies). Usually narrow-gauge railways are called railways with a track width of 600-1200 mm; roads with a smaller track width are called micro-tracks, as well as decovilles (decavilles), which is not always correct.
Narrow-gauge railways are cheaper to build and operate than standard gauge railways. Smaller sizes of locomotives and wagons allow for the construction of lighter bridges; when laying tunnels for narrow-gauge railways, it is required to extract a smaller volume of soil. In addition, steeper curves and ascents are allowed on narrow-gauge railways than on ordinary railways, which has led to their popularity in mountainous areas.
In the swamps and taiga of Western Siberia, narrow-gauge railways turned out to be an indispensable form of transport. They were used to deliver goods, equipment and people.