narrowgauge

Narrow gauge is a term used in rail transport to describe track gauges that are narrower than the standard gauge of 1,435 mm (4 ft 8 1/2 in). It covers a range of widths, including metre gauge (1,000 mm), Cape gauge (1,067 mm), and smaller gauges such as 914 mm (3 ft), 762 mm (2 ft 6 in), and 600 mm. The choice of gauge affects construction costs, stability, speed, and the ability to negotiate tight curves or steep gradients. Narrow-gauge lines are common where lower costs or difficult terrain are priorities.

Narrow-gauge railways offer advantages such as reduced construction and rolling-stock costs, lighter rails and structures, and the ability to traverse tight curves and steep grades. They are well suited to mountainous regions, mining operations, and rural or regionally focused networks. Their limitations include lower maximum speeds, reduced carrying capacity, and greater difficulty in linking with standard- or broad-gauge networks. Where interoperability is required, solutions include transshipment, dual-gauge track, or gauge-changing technologies.

Historically, narrow gauge emerged in the 19th century as an economical alternative for mountain routes and colonial railways. Metre and Cape gauges became widespread in various regions, while even smaller gauges served industrial and mining lines. Today, narrow-gauge networks remain in operation in passenger, freight, and tourist contexts, particularly in regions with challenging terrain or historical preservation. Many lines have been preserved as heritage railways, while others have been converted to broader gauges or replaced by road transport.