Southern Railway (SR) is one of the eighteen zones of Indian Railways. It is headquartered at Chennai and operates across the states of Tamil Nadu, Kerala, Andhra Pradesh and the union territory of Puducherry. The origin of the Southern Railway can be traced back to the Madras Railway formed in 1845. Southern Railway was created on 14 April 1951 by merging three state railways, namely, the Madras and Southern Mahratta Railway, the South Indian Railway Company, and the Mysore State Railway. Southern Railway maintains about 5,081 km (3,157 mi) of railway lines and operates 727 railway stations.

The history of the Southern Railway can be traced back to the Madras Railway. In 1832, the proposal to construct the first railway line in India at Madras was made by the British.^[2] In 1835, the railway track was constructed between Little Mount and Chintadripet in Madras and became operational in 1837.^[3] The Madras Railway was established later in 1845 and the construction on the first main line between Madras and Arcot started in 1853, which became operational in 1856.^[4] In 1908, Madras Railway merged with Southern Mahratta Railway to form the Madras and Southern Mahratta Railway.^[5][6]

In 1944, all the railway companies operating in British India were taken over by the Government.^[7] Post Independence, various re-grouping proposals were studied as there were 42 different railway systems. In December 1950, the Central Advisory Committee for Railways approved the plan for Indian Railways into six zonal systems and the Southern Railway zone was created on 14 April 1951 by merging three state railways, namely, the Madras and Southern Mahratta Railway, the South Indian Railway Company, and the Mysore State Railway.^[8]

Southern Railway zone covers the states of Tamil Nadu, Kerala, Puducherry and a small portion of Andhra Pradesh.^[8] Andaman and Nicobar will form part of the zone once the proposed new railway line between Port Blair and Diglipur becomes operational.^[9]

The Southern Railway is headed by the General Manager, assisted by an Additional General Manager. Southern Railway is headquartered in Chennai and is divided into six divisions namely Chennai, Tiruchirappalli, Madurai, Palakkad, Salem and Thiruvananthapuram.^[8]

The zone operates both passenger and freight trains. Various classes of passenger trains including Vande Bharat Express, Shatabdi Express and Tejas Express are operated by Southern Railways.^[10] Freight operations include container traffic from the ports, coal bound to the thermal power stations, oil and petroleum products from refineries, cement and food grains. Most of the lines inside ports, thermal stations, manufacturing industries and owned by the respective companies and the zone provides a link connecting to its network along with the wagons and locomotives. The zone has a larger proportion of passenger traffic compared to freight.^[11][12] There are about 727 stations on the Southern railway network.^[13]

Chennai Suburban Railway is the commuter rail system in the city of Chennai, operated by the Southern Railways. The system operates four lines with a track length of 1,174.21 km (729.62 mi), of which 509.71 km (316.72 mi) are dedicated dual tracks for EMUs.^[33][34]

Nilgiri Mountain Railway is a 1,000 mm (3 ft 3+3⁄8 in) metre gauge railway in Nilgiris district connecting Mettupalayam and Udagamandalam. It was built during the British Raj in 1908 and is currently operated by the Southern Railways.^[35][36] It is the only rack railway in India and operates on its own fleet of steam locomotives between Coonoor and Udhagamandalam.^[37] In July 2005, UNESCO added the Nilgiri Mountain Railway as an extension to the World Heritage Site of Mountain Railways of India.^[36]

• Zones and divisions of Indian Railways
• All India Station Masters' Association (AISMA)