Formerly known as Madras, Chennai is the capital of the southern state of Tamil Nadu. It is India’s fourth-largest city with a population around eight million. 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.
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 the 40% of the project, the balance being raised through long-term loans; the Japanese Bank for International Cooperation is a principal source.
The metro will supplement 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 a 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 project consultant was the Delhi Metro Rail Corporation Limited (DMRC). Unlike Delhi and other Chennai rail operations, the new metro will be built to 1,435mm gauge. The first phase proposal is for two corridors to integrate with existing public transport services, including the heavily used bus terminal and Central station.
Corridor 1 will be the 23km (14.4 miles) between termini at Washermenpet and Chennai International Airport, India’s third busiest and with a current suburban railway link at Tirusulam. Running west and with an interchange with Corridor 1 at Alandur, Corridor 2 will be 22km (13.8 miles) between Chennai Central and St Thomas Mount to the south. There will be a northern connection with Corridor 1 at Chennai Fort.
Around 57% of the lines will be on new elevated alignments, an approach widely used on modern Indian systems to allow for relatively rapid installation at lower cost than tunnelling.
For Chennai, a given distance of elevated track can be created for around a third of the cost of that underground. Ballast-free slab track is proposed to reduce maintenance, with a 750V dc third rail power supply. According to location, metro stations will be a mix of island and side platform types.
There is a challenging target to complete phase 1 in six years, with DMRC anticipated as being involved through the whole process. At the end of 2008, CMRL was requesting tenders for civil engineering works on elevated sections and for valuation of properties to install infrastructure. Compulsory powers are available, although the aim is for land transfer through agreed selling prices. The metro will however mainly use sites already in public ownership.
Interest in supplying electric multiple units is likely from international manufacturers such as Bombardier, Siemens, Rotem, Alstom or Mitsubishi, with a probable demand for a degree of domestic content in materials and production.
Beyond reference to the Delhi Metro stock, CMRL is yet to detail rolling stock requirements beyond four and six-car sets with dimensions of driver motor cars at 21.64m, motor/trailer cars at 21.34m, with a 2.9m width. On Corridor 2, ‘Koyambedu Depot-cum-Workshop’ is designated as the primary maintenance facility, with a second at Minambakkam on Corridor 1 for stabling and inspections.
Signalling and communications
The network will have a single centralised operation control centre and ATP (Automatic Train Protection) and ATS (Automatic Train Supervision) will be installed. The telecommunication system will be 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 proposes a computer-based automated fare collection system.
The start of metro services is now envisaged to be in financial year 2014–15, by which time the state government intends to have a single authority installed for maximising the potential benefits of a multi-mode public transport system. As well as adding later phases, the Chennai Metro may replace heavy rail in pre-existing proposals for new rail links around the metropolitan area such as that between Avadi and Sriperumbudur.