The Kolkata Metro is a rapid transit system serving the city of Kolkata and the Kolkata Metropolitan Region in West Bengal, India. Opened in 1984, it was the first operational rapid transit system in India. , it has four operational lines: the 32.13 km long Line 1 (Blue Line) from Dakshineswar to Kavi Subhash, 14.1 km long Line 2 (Green Line) from Salt Lake Sector V to Howrah Maidan (excluding the under construction section between Sealdah and Esplanade), 7.75 km long Line 3 (Purple Line) from Joka to Majerhat and 5.4 km long Line 6 (Orange Line) from Kavi Subhash to Hemanta Mukhopadhyay for a total of 59.38 km. Two other lines named Line 4 (Yellow Line) and Line 5 (Pink Line) are in various phases of construction and planning. The system has a mix of underground, at-grade, and elevated stations using both broad-gauge and standard-gauge tracks. It operates on a 750 V DC Third rail system. Trains operate between 06:50 and 22:40 IST and the fares range from ₹5 to ₹50. The Kolkata Metro was initially planned in the 1920s, but construction started in the 1970s. The first underground stretch, from Bhawanipore (now Netaji Bhawan) to Esplanade, opened in 1984. A truncated section of Line 2, or the East–West Corridor, from Salt Lake Sector V to Phoolbagan opened in 2020. Line 3, or the Joka-Esplanade Corridor (currently truncated in Majerhat), opened in 2022 while Line 6, from Kavi Subhash to Hemanta Mukhopadhyay, opened in 2024. It is the second busiest metro network in India after the Delhi Metro and is the fifth-longest operational metro network in India after the Delhi Metro, Namma Metro, Hyderabad Metro, and Mumbai Metro. Metro Railway, Kolkata and Kolkata Metro Rail Corporation are the owners and operator of the system. On 29 December 2010, Metro Railway, Kolkata, became the 17th zone of the Indian Railways, completely owned and funded by the Ministry of Railways. It is the only metro system in the country to be controlled by Indian Railways. Around 300 daily train trips carry more than passengers.

History

Early attempts

In the September 1919 session of the Imperial Legislative Council at Shimla, a committee was set up by W. E. Crum that recommended a metro line for Kolkata (formerly Calcutta). This line was supposed to connect Bagmari in the east to Benaras Road, Salkia, in Howrah in the west via a tunnel beneath Hooghly River. The estimated construction costs were £3,526,154, about inr 364000000 based on current exchange rates, and the proposed deadline was 1925–1926. The proposed line was 10.4 km long, about 4 km shorter than the current East-West Corridor, which would connect East Bengal Railway in Bagmari and East Indian Railway in Benaras Road. The tickets were priced at 3 annas (₹ 0.1875) for the full trip. Crum also mentioned a north–south corridor back then. An east–west metro railway connection, named the "East–West Tube Railway", was proposed for Kolkata in 1921 by Harley Dalrymple-Hay. All the reports can be found in his 1921 book Calcutta Tube Railways. However, in 1923, the proposal was not undertaken due to a lack of funds.

Planning

Then the Chief Minister of West Bengal, Bidhan Chandra Roy, reconceived the idea of an underground railway for Kolkata from 1949 to 1950. A team of French experts conducted a survey, but nothing concrete materialized. Efforts to solve the traffic problem by augmenting the existing fleet of public transport vehicles hardly helped, since roads accounted for only 4.2 percent of the surface area in Kolkata, compared with 25 percent in Delhi and 30 percent in other cities. To find alternative solutions, the Metropolitan Transport Project (MTP) was set up in 1969. The MTP, with the help of Soviet specialists, Lenmetroproekt and East German engineers, prepared a master plan to provide five rapid-transit (metro) lines for the city of Kolkata, totaling a length of 97.5 km, in 1971. Three were selected for construction. These were: The highest priority was given to the busy north–south corridor between Dum Dum and Tollygunge over a length of 16.45 km; work on this project was approved on 1 June 1972. A tentative deadline was fixed to complete all the corridors by 1991.

Construction

The foundation stone of the project was laid by Indira Gandhi, the Prime Minister of India, on 29 December 1972, and construction work started in 1973–74. Initially, cut and cover along with slurry wall construction to handle soft ground, was recommended by the Soviet Union consultants. Later, in 1977, it was decided to adopt both shield tunneling and cut and cover methods for the construction of underpopulated areas, sewer lines, water mains, electrical cables, telephone cables, tram lines, canals, etc. The technology was provided by M/s NIKEX Hungarian Co., Budapest. In the early days, the project was led by the Union Railway Minister from West Bengal, A. B. A. Ghani Khan Choudhury, often against the prevailing socio-political stance of his contemporaries in the West Bengal government. From the start of construction, the project had to contend with several problems including insufficient funds (until 1977–1978), a shifting of underground utilities, court injunctions, and an irregular supply of vital materials. In 1977, an injunction for the allocation of new funding was passed by the newly elected Jyoti Basu government. Despite all the hurdles, services began on 24 October 1984, with the commissioning of a partial commercial service covering a distance of 3.40 km with five stations served between Esplanade and Bhowanipur (currently Netaji Bhavan). The first metro was driven by Tapan Kumar Nath and Sanjoy Kumar Sil. The service was quickly followed by commuter services on another 2.15 km stretch in the north between Dum Dum and Belgachhia on 12 November 1984. The commuter service was extended to Tollygunge on 29 April 1986, covering a further distance of 4.24 km, making the service available over a distance of 9.79 km and covering 11 stations. However, the services on the north section were suspended starting 26 October 1992, as this small, isolated section was little used. The Line 1 was almost entirely built by cut and cover method, while a small 1.09 km stretch between Belgachia and Shyambazar was built using shield tunneling with compressed air and air locks, since the alignment crossed a railway yard (now Kolkata railway station) and Circular Canal. After more than eight years, the 1.62 km Belgachhia–Shyambazaar section, along with the Dum Dum–Belgachhia stretch, was opened on 13 August 1994. Another 0.71 km stretch from Esplanade to Chandni Chowk was commissioned shortly afterward, on 2 October 1994. The Shyambazaar-Shobhabazar–Girish Park (1.93 km) and Chandni Chowk–Central (0.60 km) sections were opened on 19 February 1995. Services on the entire stretch of the Metro were introduced from 27 September 1995 by bridging the 1.80 km gap with Mahatma Gandhi Road metro station in the middle. In 1999–2000, the extension of Line 1 along an elevated corridor from Tollygunge to New Garia, with six stations, was sanctioned at a cost of inr 9070000000. The section was constructed and opened in two phases, Mahanayak Uttam Kumar to Kavi Nazrul in 2009 and Kavi Nazrul to Kavi Subhash in 2010. In the north, the line was extended till Noapara from Dum Dum on 10 July 2013. The latest extension opened was the 4.1 km stretch from Noapara to Dakshineswar on 23 February 2021. The master plan of the metro corridor was made in 1971 along with the North–South Corridor, connecting the office district of Bidhannagar with the twin city and transportation hub Howrah via another transport hub of the city, Sealdah, and the central business district Esplanade by an underwater metro line. It is a inr 48746000000 project, sanctioned in 2008 by Prime Minister Manmohan Singh. The foundation stone was laid on 22 February 2009 and construction started in March 2009. The autonomous Kolkata Metro Rail Corporation (KMRC) was formed to implement the project. The Government of India (Ministry of Urban Development) and Government of West Bengal each had a half-share in it. Later, the Government of West Bengal pulled out from it, and the shares were transferred to the Ministry of Railways.

Route realignment

The realignment led to many other issues and delays. Some of the biggest issues were the H-piles under the Esplanade metro station and the Bowbazar mishap. Per the 1971 master plan, the East-West Corridor was supposed to pass under Central metro station, so the square foundational beams in Esplanade were not removed. Since the Tunnel Boring Machines (TBMs) cannot cut through steel, another small tunnel was dug using New Austrian tunneling method (NATM) and the H-piles were cut manually. This extended the tunneling process by one and a half months. In September 2019, during the construction of the eastbound tunnel (from Esplanade to Sealdah), a TBM hit an aquifer under Bowbazar, causing a major collapse in the area, delaying work in that section for several months. Around 80 houses were damaged and many buildings were declared unsafe, affecting more than 600 people. Later subsidence in the area was checked using grouting.

Expansion planning

By 2011–2012, the Railway Ministry had announced plans for the construction of five new metro lines and an extension of the existing north–south corridor. These were:

Major modifications

A new four-platform interchange station was constructed at Noapara and Kavi Subhash. This acts as an interchange station for Line 1 with Line 4 and Line 6 respectively. For the time being, only two platforms are in use for Noapara, but once Line 4 is running, all four platforms will be operational, whereas, from 6 March 2024, all four platforms of Kavi Subhash will be operational. The existing Esplanade metro station was upgraded and a subway was constructed to the new metro station to provide an interchange among Line 1, Line 2 and future Line 3. In 2009–2010, Line 1 underwent upgrades of services and amenities and many stations were renamed after famous personalities by then Minister of Railways Mamata Banerjee.

Network

Summary

The Kolkata Metro currently operates with four lines: Line 1, Line 2, Line 3, and Line 6. These lines have a total of 50 operational stations with a further 29 under construction. Additionally, there is one more line proposed, The planned network will have a total of 21 stations, further expanding the metro's reach and capacity. The planned network consists of the entirety of Line 5; the extension of Line 2 to Teghoria and the extension of Line 4 to Barasat.

Operational

Under construction/planned

Lines

Summary

Blue line (Line 1)

Line 1, or the Blue line, of Kolkata Metro has a total length of 32.13 km serving 26 stations, of which 15 are underground, 9 are elevated and 2 at-grade. It uses the broad gauge tracks. It was the first underground railway to be built in India, with the first trains running in October 1984 and the full stretch that had been initially planned completed and operational by February 1995. The southward extension of the Blue Line to an elevated corridor from Tollygunge to New Garia was constructed and opened in two phases, Mahanayak Uttam Kumar to Kavi Nazrul in 2009 and Kavi Nazrul to Kavi Subhash in 2010. Another extension constructed was the 2.59 km elevated corridor from Dum Dum to Noapara in 2013. The last 4.13 km extension from Noapara to Dakshineswar opened in 2021, thus completing the Blue line. A northward extension from Dum Dum to Dakshineswar (6.20 km) was sanctioned and included in the 2010–2011 budget at a cost of inr 2275300000. The commercial operations for Dum Dum to Noapara (2.09 km) were commissioned in March 2013, and construction from Noapara to Dakshineswar with an interchange with Line 5 at Baranagar (2.38 km) is being executed by RVNL. This section is opened on 23 February 2021 for general public with a projected ridership of 55,000 by 2030. An upgrade of the existing signaling system from Indian Railways Signalling to Communication Based Train Control was proposed by Metro Railway, Kolkata, at a cost of inr 4670000000, and was sent to Indian Railways. Work is also ongoing to upgrade it's old stainless steel third rail to more modern and sustainable aluminium third rail. This could help reduce energy loss by about 84% and solve the problem of voltage drops. This also decrease the time interval between trains to just 90 seconds from 5 minutes. Indian Railways approved the proposal, installation work of Communication Based Train Control signal is expected to be started after conversation of third rail (which is expected to be completed within 2 years) and will be completed within 2–3 years.

Green line (Line 2)

Green Line or Line 2, is the metro corridor to connect Kolkata with Howrah by an underwater tunnel below the Hooghly River. The length was supposed to be 14.67 km, 8.9 km underground and 5.77 km elevated. However, the project was stalled several times due to land acquisition and slum relocation issues. A major route realignment in 2013 increased the length to 16.55 km. The elevated stretch is 5.77 km long while the underground stretch is 10.81 km. The planned intersection with the Blue Line at Central was re-aligned to Esplanade (interchanges with Blue line and Purple line). In September 2019, during the construction of the eastbound tunnel between Sealdah metro station and Esplanade metro station, a Tunnel boring machine hit an Aquifer at Bowbazar, causing a major collapse in the area, delaying work on that section for several months. These issues have caused massive delays to the project, and foreign currency losses had led to an 80 percent cost escalation of the project to nearly inr 89969599999.99998. Between Mahakaran and Howrah, the metro runs under the Hooghly River– the biggest and the only underwater metro tunnel in India. Transfer stations with railways are located at Two major railway stations, Sealdah and Howrah. A new elevated extension from Sector-V to Teghoria was sanctioned a distance of 5.5 km at a budget of inr 6740000000 in 2016. From Teghoria, passengers can take the Orange Line metro. The line from Sector-V to Salt Lake Stadium was inaugurated on 13 February 2020 by the then Minister of Railways Piyush Goyal after 11 years of construction. Services to Phoolbagan metro station, the first underground station of the line, were extended on 4 October 2020. The extension added 1.66 km to the existing line. On July 11, 2022, this line was extended till Sealdah. On 6 March 2024, the Esplanade - Howrah Maidan section was inaugurated by Prime Minister Narendra Modi, leaving only 2.9 km between the two functional stations to be joined.

Purple line (Line 3)

Previously, the stretch from Thakurpukur to Majerhat was surveyed as a branch line of the circular railway, and a metro line from Majerhat to Dakshineswar via Sealdah (interchange with Green line) was planned. This plan was scrapped and a new metro line from further south in Joka to BBD Bagh was sanctioned in 2010–2011 with a total length of 17.22 km at an anticipated cost of inr 26190200000. Later the route was truncated to Esplanade. The corridor runs along Diamond Harbour Road, Khidirpur Road, and Jawaharlal Nehru Road, major arterial roads of Kolkata, and has passenger interchange facilities with the Blue Line and Green line at Esplanade and Blue line at Park street. The proposed Esplanade station will not be the same as that of the Blue Line but a different station that will also serve the Green Line. The line now has a new depot in Joka. Due to land acquisition problems and objections from the Ministry of Defence, construction has been delayed several times since the beginning. Defence Ministry objected that the elevated corridor would overlook the Eastern Command headquarters at Fort William, Ordinance Depot at Mominpore. The change in alignment from elevated to underground increased the construction cost of the stretch from inr 1390000000 to inr 30000000000. The work resumed in several phases and new bids were invited by Rail Vikas Nigam Limited (RVNL) in April 2020. It is India's first metro line to run on indigenous head hardened rails, manufactured by Jindal Steel & Power. The extension of this line to IIM and Diamond Park for 2 km was sanctioned in the 2012–2013 Budget at a cost of inr 2944900000. The work is being executed by RVNL. The line has 3 phases: The Mominpur metro station was planned to be built across a 2500 sq. m area. However, the Ministry of Defence objected to the elevated structure, saying that it would overlook the Ordnance depot. This forced RVNL to stall the entire project, and RVNL almost dropped the station from the plan even though it alone would have a projected 20,000 passengers during peak hours. Underground Mominpur station was also not possible due to the sharp gradient from Taratala metro station. After a series of discussions and consultations with the Ministry of Defence and Government of West Bengal in 2016, it was decided to shift the station around 1 km northward, near the Alipore Bodyguard Lines. But, after a year Defence Ministry approved the Mominpur metro station in its original location as the change in alignment would have delayed the project and budget overrun. It will be the last elevated station of the corridor. Now, the proposed underground Khidirpur metro station is planned at the Alipore Bodyguard Lines. There were also hurdles regarding clearance for tunneling under defence lands. In 2020, the Defence Ministry eased out the process as lease rent wasn't required anymore for tunneling as long the overground ownership of the land did not change. On 30 December 2022 the Joka - Taratala section and on 6 March 2024, the Taratala - Majerhat section was inaugurated remotely by Honourable Prime Minister Narendra Modi, completing the 7.75 km Phase 1 stretch.

Yellow line (Line 4)

The work of integrating the Circular Railway from Dum Dum Cantonment to Biman Bandar into a 6.249 km new metro line from Noapara to Netaji Subhash Chandra Bose International Airport was sanctioned in the 2010–2011 budget. The cost of the project is inr 1848300000.0000002. An eastward extension from Biman Bandar to Barasat over 10.627 km was also sanctioned and included in the 2010–2011 budget. The cost of the project is inr 23977199999.999996. The work on this project from Noapara to Barasat is being executed by Metro Railway, Kolkata. Due to multiple delays and hurdles, the total cost of the project had grown to inr 48295700000. Following an objection from the Airports Authority of India (AAI), the route was further reworked. Instead of using the Circular Line's Jessore Road and Biman Bandar railway station, Jessore Road and Jai Hind metro station were planned at-grade and underground, respectively. This stretch will continue underground till Barasat after Prime Minister Narendra Modi's approval which was till New Barrackpore earlier. As of 2024, the construction work has started from the airport to New Barrackpore underground link, and the bidding for the New Barrackpore to Barasat line extension is expected to start.

Pink line (Line 5)

The Pink Line is the northward extension from Baranagar to Barrackpore [12.45 km]. It was sanctioned at a cost of inr 20696000000 in the 2010–2011 budget. This line was meant to enable a quick commute from the northernmost suburbs to South Kolkata. The work corridor is being executed by RVNL. As of May 2021, no physical construction has commenced, and the project has been stalled as metro construction would affect the water pipelines along Barrackpore Trunk Road. To avoid this, another proposal was made to continue this line through the Kalyani Expressway. Eleven metro stations were planned on this route.

Orange line (Line 6)

A connection between New Garia and Netaji Subhas Chandra Bose International Airport (29.87 km) via EM Bypass, Salt Lake and Rajarhat-New Town was sanctioned to reduce travel time between the southern fringes of Kolkata and the airport. Work on this line was inaugurated by the then Railway Minister Mamata Banerjee on 7 February 2011 with a project deadline of six years. The link between Kavi Subhash and Jai Hind, to be set up at a cost of inr 42595000000, will have 24 stations with the terminal Jai Hind metro station being an underground one. The work is executed by Rail Vikas Nigam Limited. Jai Hind metro station will also have a stabling yard, and will be the largest underground facility in the country. This line will have interchanges at Kavi Subhash (with Blue line); Salt Lake Sector V (with Green line) and Teghoria/VIP Road (again with Green line). In July 2020, bids were invited by RVNL to complete the sections left due to various reasons and hurdles. Initially, the Jai Hind metro station was planned to be elevated. However, the AAI objected that the elevated stretch up to the airport might pose a threat to aircraft, so the route was further reworked and the station was shifted underground, 150 m from the Airport terminal building. As per another revised plan, this line will continue till Barasat and the Yellow line would terminate at Jai Hind. There are also possibilities that Jai Hind metro station would serve as a junction of three lines, i.e. Noapara–Jai Hind, Kavi Subhash–Jai Hind, and Jai Hind–Barasat. On 6 March 2024, the Kavi Subhash-Hemanta Mukhopadhyay section was inaugurated, completing the 5.4 km Phase 1 stretch.

Proposed expansions

In 2012, RITES, surveyed 16 new routes for connecting the suburban areas to the city. The key routes were:

Owners and operators

Since the formation of the Metropolitan Transport Project (MTP) in 1969, Kolkata Metro has always been under the Indian Railways, directly or indirectly. It is the only metro in the country to be controlled by Indian Railways. On 29 December 2010, Metro Railway, Kolkata, became the 17th zone of the Indian Railways, completely owned and funded by the Ministry of Railways. Although Kolkata Metro Rail Corporation was formed with 50-50 shares of the Government of West Bengal and the Government of India, as the implementing agency of the East–West Corridor, later majority shares were transferred to Indian Railways. In July 2019, the operation of Green line was handed over to Metro Railway, Kolkata.

Services

Operations

Originally, There are a total of 358 services every day. But, the services and timings were changed due to the COVID-19 pandemic and as of November 2024, it operates between 06:50 and 22:40 IST. Trains operate at an average speed of 23 km/h and stop for about 10 to 20 seconds at each station, depending on the crowd. All stations have display boards showing the terminating station, current time, scheduled time of arrival and estimated time of arrival of trains in Bangla, Hindi and English. Digital countdown clocks are also present in the stations. The coaches of blue and green line have line route-maps and all line have speakers and displays, which provide details of upcoming stations in the three languages. Navigation information is available on Google Maps. Kolkata Metro has launched its own official mobile app 'Metro Ride Kolkata' for android & iOS smartphone users which provides information regarding station, train timing, fare and has online smart card recharge facility along with mobile QR code ticketing.

Seat reservation

In 2008, the Kolkata Metro Railway experimented with the practice of reserving two entire compartments for women. This system was found to be ineffective and caused inconvenience for a lot of commuters (including women) and the plan was dropped. Now, certain sections of seats in each compartment are reserved for women, senior citizens and the physically challenged. The four-seat sections at each end of a coach are reserved for senior citizens and the physically challenged, and the two middle seat sections, between the general seat sections on each side, are reserved for women.

Fare

The fare is based on the predetermined distance formulas. Kolkata Metro has the lowest starting fare in the country of inr 5. For Blue Line, the fare ranges from inr 5 to inr 25,for Green Line, its inr 5 to inr 30, for Purple Line, the fare ranges from inr 5 to inr 20 and Orange line fare range is from inr 5 to inr 20.

Tickets

After using the magnetic ticketing strip system from 1984 to 2011, Kolkata Metro introduced Radio-Frequency Identification (RFID) tokens by Centre for Railway Information Systems (CRIS) in partnership with Keltron in August 2011. The old magnetic strip reader gates were replaced with new RFID readers. The gates are AFC types of gates. These tokens are touched on the machine to enter the station, while to exit from the destination station, it is required to submit the token into the machine. The current tokens are coin-shaped and made of plastic.

QR Code Ticket

The Kolkata Metro has introduced a QR code ticketing system on several lines, including the Blue Line (Line 1), Green Line (Line 2), and Orange Line (Line 6), with plans to extend this system to more lines in the future. This system allows commuters to purchase and use QR code tickets for seamless travel. Commuters can also opt for mobile QR code tickets via the Metro Ride Kolkata app, available on both Google Play Store and iOS App Store. Only one person can use a mobile ticket at a time. Users have the option to take a screenshot of the QR code ticket for easy access during travel. Additionally, the app offers a smart card recharge feature, allowing passengers to top up their metro cards digitally. The balance can then be updated at any Add Value Machine (AVM) located in metro stations. The app also provides real-time metro route and timing information, further enhancing the commuting experience.

Smart Card

After introducing RFID tokens, Kolkata metro introduced a Smart Card service provided by CRIS. Earlier, four different types of smart cards were used: Minimum Multi Ride (MMR), Limited Multi Ride (LMR), General Multi Ride (GMR) and Extended Multi Ride (EMR). They were withdrawn on 7 November 2013 and a single type of Smart Card (General Smart Card) was introduced. Two new types of Tourist Smart Cards were also introduced (Tourist Smart Card – I and Tourist Smart Card – II). There is a compulsory refundable security deposit of inr 60. The card is common for both the Blue line and the Green line. Online smart card recharge facility was launched on 1 July 2020. These smart cards are not required to be submitted to the AFC gates at the arriving station and can be carried by the passengers. These cards are required to be recharged if the previously recharged money is already spent.

Tourist Smart Card

Two new types of Tourist Smart Cards were also introduced (Tourist Smart Card – I and Tourist Smart Card – II). This type of smart card is for tourists and has unlimited rides. They cost inr 250, valid for a day and inr 550, valid for three days. A security deposit of inr 60 is also charged.

Durga Puja special services

The metro railway runs special night-long services during Durga Puja (Maha Saptami to Maha Navami) to help people travel faster and more conveniently for pandal-hopping. The services start at 13:00 and operate till 04:00 the next day. Pre-puja services are also run.

Security

All stations are equipped with closed-circuit cameras, metal detectors and baggage scanners. The Railway Protection Force provides security on the premises. Smoking is strictly prohibited in the metro premises. All stations in the Green Line have half-height and full-height platform screen doors for elevated and underground stations, respectively.

Other facilities

All stations have televisions that broadcast news and songs. WiFi was introduced at Park Street and Maidan metro station in 2016. Gradually, it was expanded to all the stations. The service is provided by Reliance Jio. Most stations have services such as ATMs, food outlets, and chemist stalls. To ease crowding for recharging smart cards, two Automatic Card recharge machines were installed at Dum Dum. On account of the Swacchota–i–Seba (in English, Cleanliness is service), a nationwide awareness and mobilization campaign on cleanliness, plastic bottle crushers were placed at multiple stations.

Ridership

Kolkata Metro is the 2nd busiest metro system in India. 2,465 travel by every Metro train in Kolkata against 1,110 in Delhi metro. Kolkata Metro carries around 700,000 people daily. The daily and annual ridership has consistently risen since 1984. Low fares and fast and convenient travel have contributed to the high ridership figures. During the 2019 Durga Puja, there was a record ridership of.

Infrastructure

Rolling stock

Depots and yards

There are 5 operational depots now. The Noapara, Tollygunge and New Garia depots serve the Blue Line, the New Garia depot also serve the Orange Line, while the Central Park depot serves the Green Line and the Joka depot serves the Purple Line A depot at New Town for Orange Line and a yard at Airport are under construction.

Stations and electrification

Kolkata Metro has 50 operational stations, of which 21 are underground, 26 are elevated and 3 are at grade. Currently, Noapara is the largest metro station in the system and it will be the interchange station for the Blue Line and Yellow Line. Howrah metro station is the deepest metro station in India. The standard length of platforms in Kolkata Metro is 170 m. The metro stations of Gitanjali and Netaji have the shortest platforms of 163 m. The average length between any two stations is 1.14 km. The shortest distance is 0.597 km between Central and Chandni Chowk, and the longest distance is 2.38 km between Noapara and Baranagar. Since the Kolkata Metro has electrification, electricity substations were built in Jatin Das Park, Central and Shyambazar.

Signalling and telecommunication

An upgrade of the existing signaling system of the North-South corridor from Indian Railways Signalling to Communications-based train control (CBTC) was planned by Metro Railway, Kolkata at inr 4670000000 and the proposal was sent to Indian Railways, so that time interval between trains can be decreased to just 90 seconds from 5 minutes. In August 2019, Indian Railways gave the go-ahead to the proposal, and installation work is supposed to be complete within 2–3 years.

Public address system

PA systems are present at all stations and their premises. A station master can make a necessary announcement to the passengers and staff, overriding the ongoing local announcement. Train PA systems are controlled by the motormen for announcements to passengers on the particular train.

Issues

Since the Kolkata Metro was constructed in the 1970s, there were some technical limitations. Due to the tunnel dimensions, and being under Indian Railways, Kolkata Metro opted for an Indian metre gauge shell (2.7 m width) mounted upon broad gauge bogies. The rakes have to be custom built and require a special assembly line involving additional costs thus limiting the options for rake manufacturers for Blue line. From its inception, the coaches were manufactured by ICF, which lacked the pre-requisite knowledge for manufactured non-air-conditioning rakes. The 3000 and 4000 series rakes were faulty and delivered without any trials. In addition, Indian Railways signaling is used instead of European signaling. All of these factors have led to snags, delays, and accidents. Unlike Delhi Metro, Kolkata Metro is owned and operated by Indian Railways instead of an autonomous body, and it relies solely on Indian Railways for every decision, from funding to route realignment.

Underground tunnels

In densely populated areas, there are no free spaces left to build elevated metro tracks and stations. As a result, underground systems are constructed in these areas. However, the construction of an underground metro tunnel in the Bowbazar area has caused cracks in the houses of many residents. Consequently, the metro authority had to evacuate the people, leading to massive delays and slow development in the construction of the metro railway in that area.