Green Line (Kolkata Metro)

Green Line, also known as East–West Metro, is a rapid transit metro line of the Kolkata Metro in Kolkata, West Bengal, India. It currently consists of two distinctly operational sections from Salt Lake Sector-V to Sealdah, and Esplanade to Howrah Maidan by going underneath the Hooghly River. A future eastern extension from Sector-V to Teghoria is planned. It will cover a distance of 23.1 km (14.4 mi) and consist of 17 stations from Teghoria (Haldiram) in the east to Howrah Maidan in the west, of which it will consist of 11 elevated and 6 underground stations, and the operational section consists of 6 elevated and 6 underground stations, with a total distance of 15 km (9.3 mi). It is expected to derive a very high ridership, since it will connect India's two largest commuter railway and long-distance railway terminals, Howrah and Sealdah, along with two of its largest business districts, BBD Bagh and Salt Lake Sector V. At present, more than 100,000 passengers commute through the line every day, and this figure is expected to go up to 1 million after it gets fully completed by 2035. It will also connect the industrial hub of Kolkata, i.e., Howrah and the IT hub of Kolkata, i.e., Salt Lake Sector-V. It has interchange with Blue Line at Esplanade and will eventually connect with Purple and Orange Lines.
The Green Line has India's first and biggest underwater metro tunnel, along with the deepest metro ventilation shaft. In the deepest metro shaft, the Howrah metro station is be the deepest metro station in India, at a depth of 33 m (108 ft). The first phase between Salt Lake Sector V and Salt Lake Stadium was inaugurated by the then Minister of Railways, Piyush Goyal, on 13 February 2020, and commercial services started from 14 February 2020. The underground stretch till Phoolbagan was opened on 4 October 2020 by the current Minister of Railways, Ashwini Vaishnaw, and then till Sealdah was opened on 12 July 2022. The section between Esplanade and Howrah Maidan was inaugurated by Prime Minister Narendra Modi on 6 March 2024, leaving the gap between Esplanade and Sealdah as the only remaining unopened section. On 21st January 2025 trial run started between Sealdah-Esplanade section.
The master plan had already identified the corridor way back in 1971. But the success of the Delhi Metro contributed to the sanction of the East–West Metro corridor, which would connect Howrah railway station with the satellite city of Salt Lake. In January 2004, the Vadodara-based Pacific Consultant International Group conducted a feasibility study for the line. The report proposed the route and tubular structures be under the Hooghly River, a distributary of the Ganga River.
A new organisation called the Kolkata Metro Rail Corporation Limited (KMRCL) was formed, which would be executing the operations of this line, by commencing construction in 2009. Of the KMRC's eight directors, four each were from the Governments of West Bengal and India. The cost was being shared between the state government as 30 percent, the Union Urban Development Ministry as 25 percent, and the Japan Bank for International Cooperation (JBIC) as 45 percent. But in 2011, after state government disinvested from the project, most of the share of this project went to Indian Railways, the owner of the Kolkata Metro, and with the JBIC. The project is estimated at a cost of ₹5,000 crore (US$580 million). While by 2019, the cost escalated to ₹8,000 crore (equivalent to ₹99 billion or US$1.2 billion in 2023).
Due to major setbacks, such as land acquisition, slum relocation, and route alignment problems, the project got delayed. The East-West Corridor was originally slated to be operational by 2012, but was later pushed back to 2015. The project was implemented in four phases. The first phase, from Salt Lake Sector V to Salt Lake Stadium, became operational on 13 February 2020. The second phase, to Phoolbagan opened on 4 October 2020. The third phase to Sealdah became operational from 14 July 2022, and part of the final phase between Esplanade and Howrah Maidan, which includes the journey through the tubular tunnels under the Hooghly River, became operational on 6 March 2024. This made the line and the Kolkata Metro the first metro to run underwater in India, leaving the gap between Esplanade and Sealdah as the only remaining unopened section of the line.
Just before the tunnel enters the underwater segment, lies a ventilation shaft on the Kolkata bank of Hooghly River, which is the deepest of its kind in India, at 44 metres (144 ft) below ground level.
As of March 2025
On 3 February 2020, the final inauguration date was revealed. After 11 years, since the construction started, the first phase of the line was inaugurated on 13 February by Union Minister of Railways Piyush Goyal, with commercial services to start the very next day. The service will start from 8 am and ends at 8 pm, with 37 pairs of services a day. 5 rakes would run at a frequency of 20 minutes. Dipak Kumar drove the first train.
In October 2021, services up to Phoolbagan were extended as a part of Phase 1A.
On 14 July 2022, the first commercial run from Sealdah metro station was made, as a part of Phase 2.
On 6 March 2024, the truncated route between Esplanade and Howrah Maidan was inaugurated by Prime Minister Narendra Modi.
All the stations in this line are equipped with Platform Screen Doors to keep people away from the tracks for greater safety. Mott MacDonald is the detailed design consultant for all the elevated stations, whereas Lee Harris Pomeroy Architects have designed all the underground stations. Out of the 6 underground stations, 3 have been built by ITD Cementation, a part of the Italian-Thai Development Public Company, and the other 3 by Afcons Infrastructure, including the 520 meters underwater stretch. All the elevated stations were built by Kolkata-based Simplex Infrastructure ltd.
90 escalators and 40 elevators have been installed at different levels in the line to facilitate smooth mobility of passengers, including physically challenged and aged persons. The Letter of Award (LoA) for installation of forty-one escalators and twenty-six elevators for 8 stations of Phase-I has been awarded.
TVS provides a means to control smoke flow and ensure safe evacuation of passengers in case of a fire, as well as maintain an acceptable environment in the tunnel and station track ways. The Tender for the TVS was invited and the bids of eligible tenderers have been evaluated.
The PSDs are a system of full height/half height motorized sliding doors that provide controlled access to the trains and protect the platform edges. The PSD work for 6 elevated and 6 underground stations have been completed.
The line has two types of signaling equipment supplied by ANSALDO STS. One is the feature cab signaling and another is the continuous automatic train control with automatic train protection. The other signaling equipment includes an integrated system featuring a fiber optic cable, SCADA, radios and a PA system. The line also has a train information system, control telephones and a centralized clock system. The contract for AFC works has been awarded to M/s. Indra Sistemas SA (Spain).
Unlike the north–south corridor, the east–west metro will run from 8 am to 8 pm at a frequency of 1.5 minutes during peak hours and 5 minutes during non-peak hours. But in phase 1 operations, the frequency will be 20 minutes, and each will stop for 20 seconds in each station.
The Construcciones y Auxiliar de Ferrocarriles (CAF), in collaboration with Melco, was to supply 14 trains for this line. The 14 rakes were acquired at a cost of approximately €110m ₹600 crore (US$70 million). Each rake composes of 6 coaches having a capacity of 2,068 people per train. The maximum speed of the train is 90 km/h (56 mph). The first lot of trains was to be manufactured in Spain and imported to Kolkata in November 2014. The next lot was to be manufactured in India. However, the tender was cancelled by the Kolkata Metro Rail Corporation (KMRC) due to technical reasons, and excessive delay in project. Then, a re-tender was issued in July 2015. The Bharat Earth Movers Limited (BEML) emerged as the only bidder in the fourth round of bidding for providing the rolling stock. Thus, the contract for providing the rakes was awarded to the BEML. The BEML has earlier provided rakes for Delhi Metro, Bengaluru Metro and Jaipur Metro. Fourteen rakes, each with six coaches, were ordered. Out of 14, 11 rakes have already been received by the KMRC.
In December 2023, Kolkata Metro added blue light in the underwater tunnel section to give passengers a sense of feeling under Hooghly River alongside other lights in the tunnel.
The Government of West Bengal has proposed an extension to the East–West Metro line. According to this proposal, the East–West Metro will have 3 terminating stations at Howrah Maidan, Salt Lake Sector-V and the proposed Teghoria station. In Teghoria, it will be connected to the Airport-bound Orange Line, and interconnection facilities will be present. It was previously planned that the extension and the present route would converge at the Central Park Station. But now the plan is changed and it is decided to extend the line directly from Salt Lake Sector V Station. The proposed extension is under study and it will need several clearances before being implemented. Another 10 km (6.2 mi) East-West Metro extension project from Howrah Maidan to Santragachi bus terminus has also been proposed. Rail India Technical and Economic Service (RITES), and the implementing agency for this project was planned to start work on the corridor early in 2017.