The construction started on 10 June 2009 with the piling work for the elevated viaduct between Koyambedu and Ashok Nagar stretch. Construction is expected to be fully completed by February 2015. The first section to be opened will be on Line 2 between Koyambedu and St. Thomas Mount and this stretch is likely to be in operation by 2013. The construction work on the project was suspended on 9 August 2012, following an accident that killed a worker and injured six others, a day earlier. The work resumed after safety audit across its 32 stations was completed.
The tunnelling work began on 28 July 2012 at Nehru Park by means of twelve tunnel boring machines (TBMs) imported from China. Two parallel tunnels, 14.05 metres apart, were drilled at a depth of about 20 m for a length of 36,308 m. The depth of the tunnels will vary from 15 metres to 17 metres from the ground. The tunnel will have an outer diameter of 6.2 metres and an inner diameter of 5.8 metres. It will start at a depth of 9 metres from the surface.
The project is estimated to cost around INR146 billion (US$2.4 billion) for the two corridors totalling 45 km. However, the previous estimate in 2007 was INR95.65 billion (US$1.6 billion). But it is likely to increase by 23% to INR180 billion (US$3.0 billion)Tamil Nadu government in 2012–13 budget said global bids have been invited for implementing Phase I, covering 57 km and estimated to cost Rs 85 billion. The Underground tunnelling will cost about INR 3 billion per kilometre, whereas elevated track will cost about INR 1 billion per kilometre. The estimated construction cost of underground and elevated station will be INR 1 billion and INR 3 billion, respectively.
- 16 April: Planning commission gives in-principle approval for the project
- 21 November: Deal signed with Japan Banking Corporation for procuring 59% loan at Tokyo.
- 20 January: Tenders floated for Phase I of the Metro project; winning bidder yet to be announced, work to commence in the end of February or beginning of March.
- 29 January: Chennai Metro becomes one of the fastest projects to get approval from the Economic Ministry, signed for commencement by officiating Finance Minister Mr. Pranab Mukherjee.
- 13 February: The Hyderabad-based Soma Enterprise Ltd has been awarded a INR 199.2-crore (INR 1.99 billion) contract in the Chennai Metro Rail Project, marking the start of the work on the project. It has begun construction on the 4.5 km stretch elevated viaduct along the IRR (Inner Ring Road) between Koyambedu and Ashok Nagar. It does not include stations as it would be tendered separately.
- 10 March: A Five-member consortium led by Egis Rail S.A, France has been awarded the USD 30 million general consultancy contract by CMRL. The other members of the consortium are Egis India Consulting Engineers Private Ltd., India, Maunsell Consultants Asia Ltd., Hong Kong, Balaji Rail Road Systems Ltd., India and Yachiyo Engineering Co. Ltd., Japan.
- 20 May: CMRL started to evaluate the integration of Metro corridor with the planned grade separator at the junction of Arcot Road and Jawaharlal Nehru Road.
- 27 May: Trial Pile Load Tests are being conducted at three locations in Inner Ring Road (IRR) — At Ashok Nagar opposite to Karaikudi Restaurant, at vadapalani opposite to Hotel Ambica Palace Empire and at Koyambedu opposite to SAF Games Village.
- 10 June: Deputy Chief Minister of Tamil Nadu Thiru. M.K.Stalin inaugurated the piling work for the construction of elevated viaduct from Koyambedu to Ashok Nagar.
- 23 July: Pre-qualification tenders invited by EMBYE consultant for the rolling stock.
- 30 July: Soil tests conducted by DMRC at Wimco Nagar, Periyar Nagar and Neydhal Nagar in Tiruvottiyur for Chennai Metro Extension.
- 26 August: Tenders invited for the elevated viaducts for the Corridor 1 from Saidapet including station viaducts until OTA and for Corridor 2 from Ashok Nagar including station viaducts until Alandur.
- 4 September: Pre-qualification tenders invited for underground stations and tunnels. Invite for bids are expected around January 2010.
- 31 December: Pre-qualification tenders invited for track works (design and build). Invite for bids are expected around May 2010.
- 11 January: Pre-qualification tenders invited for power supply system and overhead equipment (design and build). Invite for bids are expected around May 2010.
- 28 January: Larsen and Toubro (L&T) bags the contract for 9.73 elevated viaducts from Corridor 1 from Saidapet until OTA (5.17 km @ INR 1733.0 million) and for Corridor 2 from Ashok Nagar until St. Thomas Mount (4.56 km @ INR 1411.3 million) valued together at INR 3144.3 million.
- 12 February: Tenders invited for 10 elevated stations and an integrated viaduct-flyover @ vadapalani.
- 12 March: Tender invited for Koyambedu Depot pre-filling and two PQs invited for Telecom, Platform Screen Doors & Signalling and Lifts & Escalators.
- 29 March: Chennai Metro Project Phase II receives INR 29326 million loan agreement from Japan. Finance Ministry of India signs agreement with Japanese Ambassador to India Hideaki Domichi.
- 19 April: Tender for pre-filling of Koyambedu depot has been awarded to Tantia Construction Limited for 205.2 million.
- 22 June: Tenders for 10 elevated stations have been awarded. 5 stations in – Koyambedu, CMBT, Arumbakkam, Vadapalani and Ashok Nagar/K.K Nagar as 1 package at a cost of 1395.4 million and another 5 in Little Mount, Guindy, Alandur, O.T.A., and SIDCO as another package at a cost of 949.9 million have been awarded to Consolidated Construction Consortium Limited.
- 29 June: Works on Underground sections, underground stations, signalling and telecom, tracks, OHE, etc. would begin before the end of 2010–2011 financial year.
- 2 August: Rolling stock tenders have been awarded to Alstom Transport S.A & Alstom Projects India Ltd consortium at a cost of INR 14713 million. 42 train-sets of 4-car configuration (168 coaches) is to be procured. The first delivery of cars is expected to reach by end of 2012. The train sets will be equipped with air-conditioned interiors, electrically operated automatic sliding doors, regenerative braking system.
- 19 August: Phase-I extension will have 2.3 km underground and 6.6 km elevated with 7 stations.
- 30 October: Metro rail extension to Tambaram would be considered.
- 2 November: Depot work for Phase I has been awarded to L&T.
- 20 December: DMRC submitted a detailed project report (DPR) for extending Corridor-I from Washemenpet to Wimco Nagar, a distance of nine km, at an estimated cost of Rs.22.40 billion. Also the official go-ahead for starting the detailed project report (DPR) for the next phase is still awaited.
- 21 January: Rs449.22-crore contract for design and construction of track works was awarded to a joint venture of L&T and Alstom. Rs.1.98 billion contract for supply of lifts and escalators was awarded to a joint venture of Johnson Lifts Pvt. Limited and SJEC Corporation (China).
- 1 February: Transtonnelstroy-AFCONS JV bags two contracts for underground sections with value of Rs15.67 billion and Rs10.31 billion respectively. A joint venture of city-based Metro Tunnelling and L&T SUCG bagged the Rs705.75-crore contract to design and build three underground stations and associated tunnels from Nehru Park to Pachaiyappa’s College.
- 2 February: OJSC Mosmetrostroy-Gammon India JV has been awarded two underground packages for a value of INR 9328.8 million and INR 10474.2 million.
- 22 February: Contract for power supply and overhead electrification (OHE) was awarded to Siemens AG of Germany and Siemens Ltd India Consortium for Rs3.05 billion.
- 3 March: Automatic Fare Collection (AFC) system design-and-build contract to Nippon Signal Co Ltd for 1098.8 million.
- 7 March: The contract for tunnel ventilation system (design and build) was awarded to Emirates Trading Agency LLC, Dubai and ETA Engineering Private Limited, India donsortium for Rs.2418.3 million. Underground stations air conditioning system contract was awarded to Voltas ltd for Rs.1962.0 million.
- 10 August: Contract for Construction of Elevated Station at Meenambakkam, Viaduct and Cut – Cover Tunnel between OTA Station and Chennai Airport Station was awarded to Lanco Infratech Limited for 1789.4 million.
- 12 September: Work on ‘double-decker’ structure at Arcot Road–100-ft Road at Vadapalani begins. The 4-lane flyover below the Metro will be 700-m long and 18.6-m wide, with 7.5-m wide service roads and 2.5-m wide drainage-cum-footpath on either side.
- 22 March: The complex engineering of the Chennai Metro Rail construction.
- 7 April: The Madras High Court dismisses a petition filed by the Indian National Trust for Art and Cultural Heritage challenging the demolition of the rear section of the P. Orr and Sons building on Anna Salai.
- 10 September: The erection of electrical masts on elevated viaduct between Vadapalani and Koyambedu was started. 30 Masts were erected at the site and further erection is going on. In the elevated viaduct, flexible overhead catenary system is adopted.
- 24 September: The track works for about 3.5 km between Vadapalani and CMBT stations have been completed. About 2.6 km has been handed over for other system works such as OHE Erection etc.
- 4 October: Walls are being built below the surface at all underground station sites, including Mannadi, near the high court and Chennai Central, in Egmore, at Government Estate, near LIC, in Thousand Lights, near Gemini Flyover, Teynampet, Chamiers Road, Kilpauk Medical College & Hospital, Pachaiyappa’s College, Anna Nagar Tower, in Anna Nagar East and Thirumangalam.
- 6 October: Eleven TBMs have been commissioned to bore tunnels along the underground stretch. The first TBM, launched in July, has readied a nearly 100-metre-long tunnel and the second machine will be launched within a fortnight. A total of three TBMs are stationed at the May Day Park, Chintadripet. Two Tunnel Boring Machines (TBMs), just arrived from China, will soon begin boring an underground path from Saidapet to Gemini.
- 18 October: Eight cars shells required for the first two trains is completed and further fitment of cables, pipes, panels and equipments are progressing well in Alstom factory located in São Paulo, Brazil. Mock up model of the passenger saloon and cab is completed in Brazil. The saloon mockup is shipped from Brazil and is expected to reach Chennai by the end of November 2012.
- 4 December: The first model coach of Chennai Metro Rail that was manufactured in Brazil arrived in the city.
- 6 November: The test run of the Chennai Metro Rail was flagged off by the Tamil Nadu Chief Minister Jayalalithaa. The four-coach train made a small trip of one km along the test track in Koyambedu on Wednesday.
- 30 January: In the address to the state assembly for the year 2014, the Governor Rosaiah stated that, the State government would take up a detailed project report for Phase II of the project in newly identified corridors.
- 14 February: The maiden trial run for the Metro Rail was conducted between the Koyambedu and Ashok Nagar stations. The train had three trial runs, in this stretch which includes five stations – Koyambedu, CMBT,Arumbakkam, Vadapalani and Ashok Nagar. Further runs are planned at varying speeds and to be followed by software test, signal test, telecom test and train test after which an integration trial will be conducted. The final inaugration could happen, after success of all these tests and obtaining of rail safety clearance. After statutory processes, CMRL hopes to open a 9-km stretch up to Alandur to the public by July 2014.
Washermenpet – Broadway (Prakasam Road) – Chennai Central Station – Rippon Building – along Cooum River – Government Estate – Tarapore Towers – Spencers – Gemini – Anna Salai – Saidapet – Guindy – Chennai Airport.
Chennai Central – along EVR Periyar Salai – Vepery – Kilpauk Medical College – Aminjikarai – Shenoy Nagar – Annanagar East – Anna Nagar 2nd avenue – Tirumangalam – Koyambedu – CMBT – along Inner Ring Road – Vadapalani – Ashok Nagar – SIDCO – Alandur – St. Thomas Mount.