The gauge of the railway track is a minimum vertical distance between the inner sides of two tracks is called a railway gauge. That distance between the two tracks on any railway route is known as a railway gauge. Approximately 60% of the world's railway uses standard gauge. There are 4 types of railway gauge used in India:
  1. Broad gauge
  2. Metre Gauge
  3. Narrow gauge 
  4. Standard gauge (for Delhi Metro)

Broad Gauge

Broad gauge is also called wide gauge or large line. The distance between two tracks in these railway gauges is 1676 mm (5 ft 6 in). It would not be wrong to say that any gauge, wider than standard gauge or 1,435 mm (4 ft 8½ inches), is called broad gauge. The first railway line built in India was a broad gauge. This line from Bore Bunder (now Chhatrapati Shivaji Terminus) to Thane in 1853. Broad gauge railway is also used on ports for crane service etc. This gives better stability. they are even better than thinner gauges.

types of railway gauges - broad gauge

Standard Gauge 

The distance between the two tracks in this railway gauge is 1435 mm (4 ft 8½ in). In India, standard gauge is used only for urban rail. and transit systems like Metro, Monorail and Tram. The only standard gauge line in India was the Kolkata (Calcutta) tram system in 2010. All metro lines passing in urban areas will be made only in the standard gauge because it is easy to get rolling stock for the standard gauge as compared to the Indian gauge and easy to installed. the lines that are in operation are Delhi Metro, Rapid Metro,Bangalore Metro and Mumbai Metro in 2016. All these are operated separately from Indian Railways.

types of railway gauges - standard gauge

Metre Gauge

The distance between the two tracks is 1,000 mm (3 ft 3 3/8 in). The metre gauge lines reduce the cost. All meter gauge lines except the Mountain Railway which is a legacy run on a meter gauge in India will be converted into broad gauge under project Unigauge.

types of railway gauges - metre gauge

Narrow Gauge

The small gauge is called a Narrow gauge. The narrow gauge is the railway track, in which distance between two tracks is 2 ft 6 in (762 mm) and 2 ft (610 mm). There was a 1,500 km narrow gauge rail route in 2015, which is considered to be about 2% of the total Indian rail network. As the country is developing small line services are expected to be completed by 2018. Now the small lines are being converted into big lines. Trains with small bogies now will no longer be able to see much. The Darjeeling Mountain Railway has declared UNESCO World Heritage on 24 July, 2008. Kalka Shimla Railway is also very popular.

types of railway gauges - narrow gauge