Green Line, also known as East–West Metro, is a rapid transit metro line of the Kolkata Metro in Kolkata, West Bengal, India. It is India's first underwater stretch metro that passes under the Hooghly River. It currently runs from Salt Lake Sector-V to Howrah Maidan by going underneath the Hooghly River. A future eastern extension from Sector-V to Teghoria and western extension from Howrah Maidan to Santragachi Bus Terminus are planned. It will cover a distance of and consist of 24 stations from Teghoria (Haldiram) in the east to Santragachi Bus Terminus in the west, of which it will consist of 18 elevated and 7 underground stations, and the operational section consists of 6 elevated and 6 underground stations, with a total distance of .
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 the deepest metro station in India, at a depth of . The first phase between Salt Lake Sector V and Salt Lake Stadium was inaugurated by the then Minister of Railways, Shri 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, Shri Ashwini Vaishnaw, and then till Sealdah was opened on 12 July 2022. The section between Esplanade and Howrah Maidan was inaugurated by Honb'le Prime Minister of India Shri Narendra Modi on 6 March 2024. The Esplanade and Sealdah section was inaugurated on 22 August 2025.
It is expected to derive a very high ridership, since it connects India's two largest commuter railway and long-distance railway terminals, Howrah, Sealdah, Shalimar Railway station and Santragachi Railway Station in the future 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 by 2035. It also connects 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 and Purple at Esplanade and will eventually also connect with Orange at Salt Lake Sector V and Teghoria.
History 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. In 2012, the project was estimated at a cost of , while by 2019, the cost had escalated to .
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.
On 21 January 2025 trial runs started on the remaining gap between Esplanade and Sealdah, which was then opened on 22 August 2025. This connected the formerly two separate sections from Salt Lake Sector-V to Sealdah and Esplanade to Howrah Maidan together into one continuous line. This also completed the original 16-year construction project between Salt Lake Sector-V and Howrah Maidan after many years of hardships, delays and developmental work.
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 below ground level.
Current status
Elevated Corridor: The elevated section for Phase 1 is complete, including the last trials, from Salt Lake Sector V to Salt Lake Stadium. Commercial operations started on 14 February 2020. Tunnel for Phase 2: The construction of the -long tunnel has been completed. This section was constructed by ITD-ITD Cementation JV. Underground Stations for Phase 2: The works at Phoolbagan station was completed, and it is operational from 4 October 2020. Underground Stations for Phase 3: The Sealdah station was completed, and was inaugurated by the Minister of Women and Child Development, Smriti Irani, and is available for commercial usage from 14 July 2022. Tunnel for Phase 3: Tunneling work for phase 3 was completed. However, work at the shaft at Durga Pithuri Lane was ongoing. Underground Stations for Phase 4: Howrah Maidan, Howrah, Mahakaran and the new Esplanade were completed and were inaugurated on 6 March 2024. Tunnel work for phase 4: Both tunnels for phase 4 are complete. Tunneling between Esplanade and Sealdah was completed on 9 October 2020 and between Sealdah and Bowbazar shaft completed on 15 May 2021. Retrieval of the TBMs and covering of the shaft are completed. The last remaining gap between Esplanade and Sealdah stations was opened on 22 August 2025. Train Depot: Construction, electrical and mechanical work have been completed at Central Park depot, and it is presently operational. Timeline The following dates represent the dates the section opened to the public, not the private inauguration. HistoryExtension dateTerminalsLength 14 February 2020Salt Lake Sector-VSalt Lake Stadium 4 October 2020Salt Lake StadiumPhoolbagan 11 July 2022PhoolbaganSealdah6 March 2024EsplanadeHowrah Maidan22 August 2025SealdahEsplanadeTotal Salt Lake Sector-VHowrah Maidan Stations
Green Line # Station Name Distance (km) Opening Connections Layout Platform TypeEnglishBengali 1Teghoria তেঘরিয়া Proposed VIP Road (Under Construction) UndergroundTBD 2Raghunathpur রঘুনাথপুর Elevated 3Baguiati বাগুইআটি 4 Kestopur কেষ্টপুর 5 Krishnapur কৃষ্ণপুর 6Salt Lake Sector-V সল্টলেক সেক্টর-৫ 0 14 February 2020 IT Centre (Under Construction) Side 7 Karunamoyee করুণাময়ী 1.227 8Central Park সেন্ট্রাল পার্ক 0.803 9City Center সিটি সেন্টার 0.933 10Bengal Chemical বেঙ্গল কেমিক্যাল1.127 11Salt Lake Stadium সল্টলেক স্টেডিয়াম0.795 12Phoolbagan ফুলবাগান 1.6954 October 2020 Underground Island 13Sealdah শিয়ালদহ 2.30511 July 2022 Sealdah Side & Island 14Esplanade এসপ্ল্যানেড 2.631 6 March 2024 (Under Construction) 15Mahakaran মহাকরণ 0.878 Island 16 Howrah হাওড়া 2.206 HowrahHowrah Station Jetty Side & Island 17Howrah Maidan হাওড়া ময়দান 1.057 Island 18Foreshore Road ফোরশোর রোড Proposed TBD 19Coal Depot কোল ডিপো 20Shalimar শালিমার Shalimar 21Nabanna নবান্ন Elevated 22Belepole বেলেপোল 23Bakshara বাকসাঁড়া 24Santragachi সাঁতরাগাছি Santragachi 25Santragachi Bus Terminus সাঁতরাগাছি বাস টার্মিনাস
Inauguration 1st Phase 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 2020, services up to Phoolbagan were extended as a part of Phase 1A.
2nd Phase On 14 July 2022, the first commercial run from Sealdah metro station was made, as a part of Phase 2.
3rd Phase
On 6 March 2024, the truncated route between Esplanade and Howrah Maidan was opened by Prime Minister Narendra Modi.
4th Phase On 22 August 2025, the remaining Sealdah–Esplanade section was opened by Prime Minister Modi, connecting the formerly two separate sections from Salt Lake Sector-V to Sealdah and Esplanade to Howrah Maidan together into one continuous line.
Infrastructure Stations 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.
Escalators and elevators 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.
Tunnel Ventilation System (TVS) 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 evaluated.
Platform Screen Doors (PSDs) 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.
Electrification, signaling and automatic fare collection 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).
Operations Like the north–south corridor, the east–west metro runs from 6:30 am to 10:20 pm (Monday to Saturday) and 9 am to 10:20 pm (Sundays) at a frequency of 6 minutes during peak hours and 12 minutes during non-peak hours.
Rolling stock