Phase one of the Chennai Metro rail network is spread across the length of 45.046km. Credit: Ashwin Kumar / Flickr.
The Koyambedu Metro station has installed sustainable and eco-friendly green boxes. Credit: Axel Drainville / Flickr.
The first segment of section between Koyambedu and Alandur was commissioned in 2015. Credit: srini091 / Flickr.
The project was approved by the Government of India in 2016. Credit: VtTN / Wikipedia.

The Chennai Metro is a metro rail project serving the city of Chennai, Tamil Nadu, India. The project is owned and operated by Chennai Metro Rail Limited (CMRL).

The metro rail network consists of five lines, two of which are currently operational and three are under construction. The project is being supported Japan International Cooperation Agency (JICA) with a loan worth $2.8bn.

The Chennai Metro development is being executed in two phases. Construction on phase I was commenced in June 2009 and the system began operations in June 2015.

Phase one consists of line one (Blue line) and line two (Green line) and covers a length of 45.046km with 32 stations. The Blue line is being extended northwards by a length of 9.05km from Washermanpet Metro Station and Thiruvottriyur/Wimco Nagar under the phase I extension. The extension includes eight additional stations. The first trial run between Washermanpet Metro station and Wimco Nagar Metro station took place in December 2020, followed by the commissioning in February 2021.

Phase two consists of lines three, four and five, covering a total length of 118.9km with 128 stations. The foundation stone for phase two of the project was laid in November 2020 and the project completion is scheduled for 2026.

In January 2021, the Chennai Metro announced plans to build a huge depot for maintenance of trains for the corridor between Light House and Poonamalle for phase two of the project.

Need for a metro rail project in Chennai

Formerly known as Madras, Chennai is the capital of the southern state of Tamil Nadu. Chennai is part of a wave of metro development in India, all founded on a rationale of rapid urban expansion, unacceptable and unpredictable journey times by road and concern for the environment if reliance on motorised transport continues unchecked.

Growth is less attributable to high technology and the service industries than some other Indian metropolitan areas and the port of Chennai is also an established manufacturing centre, notably for the automotive industry. Like the Namma Metro in Bengalaru (Bangalore), the Chennai project learns from the experience and practices in Delhi, one of the world’s most successful modern urban rapid transit schemes.

The project

A feasibility study for the metro was carried out in 2003. Following approval in November 2007, Chennai Metro Rail Limited (CMRL) was set up by the Tamil Nadu state, as a special-purpose vehicle to implement the project.

Central and state governments are meeting 40% of the project, the balance being raised through long-term loans. The Japanese Bank for International Cooperation (JBIC) is a principal source.

The metro supplements 1,676mm gauge operations which, like most of the Chennai-based Southern Railway division of Indian Railways, are mainly geared toward passenger activity. Chennai has a three-route suburban railway, with the main focus at Chennai Central to the east (coastal) side of the city. Also, broad gauge, the free-standing 25kV ac overhead-equipped Mass Rapid Transit System (MRTS) on mostly elevated alignments remains in development.

The first line opened in 1997, but MRTS has been affected by delays and suffers from a lack of stock. An early tram system that also was used for goods was closed by the 1950s.

The underground stretch from AG-DMS to Washermanpet of blue line was opened in February 2019 and phase one of the project was also completed.

Phase one infrastructure

The project consultant was the Delhi Metro Rail Corporation Limited (DMRC). Unlike Delhi and other Chennai rail operations, the new metro was planned to be built to 1,435mm gauge. The first phase proposal included two corridors to integrate with existing public transport services, including the heavily used bus terminal and Central station.

Blueline (Corridor one) is 23.085km between termini at Washermenpet and Chennai International Airport, with a current suburban railway link at Tirusulam. The Blue line extension is a 9.051km extension from Washermanpet metro station to Wimco Nagar.

Running west and with an interchange with Corridor one at Alandur, Corridor 2 is 21.961km between Chennai Central and St Thomas Mount to the south. There is a northern connection with Corridor one at Chennai Fort.

Around 55% of the lines are underground alignments and the remaining are elevated.

A ballast-free slab track was proposed to reduce maintenance, with a 750V dc third-rail power supply.

Phase two

Phase two of the Chennai Metro rail project consists of three corridors. Corridor three will be the 45.8km between Madhavaram to Sipcot while Corridor four will be the 26.1km between Lighthouse and Poonamalle Bypass. The Corridor five will be the 47km between Madhavaram to Sholinganallur.

Rolling stock

In 2010, Alstom was awarded a contract to supply rolling stock for phase one of the Chennai Metro network. The company delivered first two Metropolis train sets in February 2014 and a total of 42 sets by 2015.

The trainsets are made of stainless steel and composed of four cars each. They are equipped with electrically operated automatic sliding doors, a regenerative braking system, and air-conditioned interiors. The operating speed of the trains is up to 80km/h.

Signalling and communications

The network has a single centralised operation control centre and ATP (Automatic Train Protection) and ATS (Automatic Train Supervision) have been installed. The telecommunication system is multi-functional embracing information, security and safety aspects. To avoid problems experienced on present operations and to facilitate cross-mode ticketing from the outset, CMRL proposed a computer-based automated fare collection system.