sínpárok

Sínpárok, often translated as "rail pairs" or "track gauge," refers to the distance between the inner edges of the two rails on a railway track. This measurement is a fundamental aspect of railway engineering and dictates the compatibility of rolling stock with specific lines. Different regions and countries have adopted various standard track gauges throughout history, leading to a complex global network of railways with differing interoperability.

The most common track gauge worldwide is standard gauge, which is 1,435 millimeters (4 feet 8 1⁄2 inches). This gauge is prevalent in North America, much of Europe, and parts of Asia and South America. However, many other gauges exist. Broad gauge, such as Russia's 1,520 mm (4 ft 11 2⁄3 in) and India's 1,676 mm (5 ft 6 in), is used in vast networks where it was historically implemented for reasons such as stability on vast plains or to hinder invading forces. Narrow gauges, typically under 1,000 mm (3 ft 3 3⁄8 in), are often found on mountain railways, industrial lines, or in areas where construction costs were a primary concern due to the lighter and less expensive infrastructure required.

The choice of track gauge impacts a railway system's infrastructure, rolling stock design, and operational efficiency. For example, trains designed for one gauge cannot run on tracks of a different gauge without modifications or the use of specialized equipment like variable gauge bogies. Maintaining consistent track gauges within a country or region facilitates seamless train operations and freight movement. When different gauges meet at borders or junctions, transshipment of goods or transfer of passengers is often necessary, which can add time and cost to transportation.