Rail gauge is a fundamental concept in the railway industry. It refers to the spacing of the rails on a railway track and is measured between the inner faces of the load-bearing rails.
The gauge determines the width and stability of the railway track, which in turn impacts the size and design of the rail vehicles that can operate on the track.
Over 60% of the world’s railway network uses the standard gauge of 1435 mm.
India has four distinct kinds of railway gauges:
- Broad gauge
- Meter gauge
- Narrow gauge
- Standard gauge (specifically used for the Delhi Metro)
- Broad gauge is a railway track configuration where the separation between the two tracks in these railway gauges is 1676 mm.
- Any gauge above the conventional gauge measurement of 1,435 mm is often referred to as a broad gauge.
- The first railway line constructed in India was a wide gauge track from Bore Bunder (now known as Chhatrapati Shivaji Terminus) to Thane in the year 1853.
- The use of broad-gauge railway systems is also seen at port facilities for the purpose of accommodating cranes and other related equipment.
- Thicker gauges provide enhanced stability and surpass thinner gauges in terms of performance.
- The separation between the two tracks is 1,000 mm.
- The installation of meter-gauge lines was undertaken with the objective of minimising expenses.
- Under the Unigauge project, it is planned to convert all meter gauge lines in India, except the Nilgiri Mountain Railway (a historical railway operating on a meter gauge) into a wide gauge.
- The smaller gauge is sometimes referred to as a narrow gauge or little line.
- The narrow-gauge railway refers to a kind of railway track characterised by a distance of 762 mm and 610 mm between the two tracks.
- The Darjeeling Mountain Railway was officially designated as a UNESCO World Heritage site.
- The Kalka Shimla Railway is well recognised and has significant popularity.
- The railway gauge in question exhibits a distance of 1435 mm between its two tracks.
- In the context of rail transportation systems in India, it is observed that the standard gauge is only used for urban rail transit systems such as Metro, Monorail, and Tram, the only standard gauge railway line in India was the Kolkata (Calcutta) tram system.
- In metropolitan regions, it is preferable to construct metro lines only using the standard gauge due to the greater accessibility of rolling equipment for this gauge, as opposed to the Indian gauge.