Chennai Mass Rapid Transit System

Chennai Mass Rapid Transit System commonly referred to as Chennai MRTS is a metropolitan Mass Rapid Transit System (MRTS) in Chennai, India. It is operated by Southern Railway of the state-owned Indian Railways. Opened in 1995, it was the first elevated railway line in India. The railway line runs from Chennai beach to Velachery, covering a distance of 19.34 km (12.02 mi) with 18 stations and is integrated with the wider Chennai suburban railway network.

While the suburban railway started has been operational since 1931, the Planning Commission of Government of India set up a team to study the adequacy and feasibility of different modes of transport and recommend development in major cities including Madras in 1965. In July 1971, eight important transport corridors including the 39 km (24 mi) north–southeastern rail corridor along the Buckingham Canal were identified for development of rail corridors. The north–southeastern rail corridor was approved by Government of India in 1983–84 with the project to be implemented in four phases. The project was taken up for implementation by the Ministry of Railways with construction beginning in 1991. The first phase from Chennai beach to Chepauk was completed in 1995 with further extension to Thirumyilai completed in 1997. Part of second phase from Thirumayilai to Thiruvanmiyur was completed in 2004 with the extension to Velachery in 2007. As of January 2024, a planned extension to St. Thomas Mount is under construction.

The Chennai MRTS line is largely elevated with at-grade sections at its terminals. The line runs at grade initially till Park Town, parallel to the suburban railway network and becomes elevated thereon, roughly following the course of the Buckingham Canal, running parallel to the Coromandel Coast till Thiruvanmiyur before deviating west towards Velachery. It uses the same broad gauge (5 ft 6in) as the suburban system, thus allowing the movements of trains between the existing suburban lines and the MRTS. The elevated tracks are built at an average height of about 14 metres (46 ft) from the ground. The Chennai MRTS uses 9-car electrical multiple unit (EMU) train sets. The trains use 25 kV overhead catenary for traction. The coaches are manufactured by the Integral Coach Factory, Chennai. The coaches are not air-conditioned and are equipped with first-class and second-class passenger seating.

As of 2015, the system had a ridership of 1 lakh (0.1 million) commuters per day. With the implementation of the Chennai Metro Rail starting in 2015 and planned expansion of the same, further expansion of the MRTS system was put on hold in 2017, with the plans for the MRTS system to be taken over by Chennai Metro Rail Limited. In 2022, the Southern Railway of Indian Railways gave an in-principle approval for the take-over under which the coaches, stations and other infrastructure will be upgraded on par with the Chennai Metro.