}
Public private partnership with RInfra A long Colaba–Bandra–Charkop line was proposed as the Yellow Line in the original Mumbai Metro masterplan unveiled by the
MMRDA in 2004. A long Bandra-Kurla–Mankhurd line and a line from Charkop to Dahisar were proposed as Line 3 and Line 4, respectively, in the same plan. In the updated masterplan, the proposed Charkop–Bandra–Mankhurd and Charkop–Dahisar lines were merged into a single Dahisar–Bandra–Mankhurd line, which would have been and had 27 stations. This was planned to be the second corridor of the Mumbai Metro. Like Line 1, this corridor was also proposed to be constructed on a public private partnership (PPP) model. Then President
Pratibha Patil launched the project in August 2009. The MMRDA appointed
Reliance Infrastructure (RInfra), in consortium with
SNC Lavalin Inc., Canada and Reliance Communication, through an international competitive bidding process to carry out this phase of the project, and the concession agreement was signed with the RInfra-led consortium in January 2010. The project was proposed to be implemented on
build–operate–transfer (BOT) basis for a concession period of 35 years, with an extension clause of another 10 years. Construction was planned to begin in August 2010 and conclude by mid-2013. However, construction work had yet to begin by December 2012, leading to calls for Yellow Lineto be cancelled outright. MMRDA officials plan to solve the problem by shifting the location of the proposed rake depot to Malwani, near
Malad. The plot does not come under the purview of the CRZ laws and therefore will not require environmental clearances. The MMRDA has said that they have not ruled out an underground line, claiming that they had considered a combination of an elevated and underground alignment but had deemed it impossible due to the large land requirement for ramps and
slip roads. On 6 September 2012, the MMRDA sent a letter to Reliance Infrastructure asking them to start work on the metro immediately or face legal action. In response to the letter, RInfra blamed the government and the MMRDA for the delayed construction work. They said that the government had failed to fulfill its contractual obligation to provide the necessary land, right-of-way permits and clearances. On 8 February 2013, then RInfra CEO Sumit Banerjee claimed that the project had not advanced because the MMRDA had failed to fulfill its share of the responsibilities. The state government had since been considering alternative sites for the depot, which might have led to complete change in the alignment of the line and could have required re-bidding for the project. On 9 August 2013,
DNA reported that an MMRDA official had informed them that a plot that was to be used as the casting yard for Line 2, was planned to be marked for use as a casting yard for Line 3. The paper called the move "a clear indication" that Yellow Line"will not take off in the near future." Chief Minister Prithviraj Chavan told the media on 30 August 2013 that "it is now clear that Mumbai's Metro II project will now not happen." On 13 November 2014, Reliance Infrastructure announced that it had terminated the agreement between the MMTPL and the Maharashtra government. RInfra stated, "Due to non-fulfilment of various critical obligations by Maharashtra government and the Mumbai Metropolitan Region Development Authority (MMRDA), the project could not take off. Even after four years, despite the best efforts of the Maharashtra government, various project impediments could not be resolved." The MMRDA issued a statement confirming that the agreement was terminated with mutual consent. No party will bare any cost as a result of the termination and the state government will return a bank guarantee of 160 crore. The MMRDA also clarified that the Yellow Lineproject had not been cancelled and will be constructed by the Mumbai Metro Railway Corp. Ltd (MMRCL) under an
engineering, procurement and construction (EPC) model.
EPC model In September 2013, the MMRDA appointed RITES to study the feasibility of constructing the proposed metro line underground. RITES also studied the feasibility of extending the corridor and merging the Charkop-Dahisar metro, proposed as a separate line, with this project. RITES submitted its final report to the MMRDA in the last week of May 2014, concluding that constructing the metro underground and extending it up to Dahisar was feasible. The merged Dahisar-Bandra-Mankhurd line would be long and have 37 underground stations. The estimated cost of construction of this line was 28,900 crore, 134% higher than the originally estimated costs of 7,660 crore for the Charkop-Bandra-Mankhurd line and 4,680 crore for the Charkop-Dahisar corridor. RITES proposed the construction of a major car depot at Oshiwara and a minor car depot at Mandale, Mankhurd on sites that were a mix of publicly and privately held land. The extension of the line to Mankhurd was proposed to resolve land acquisition issues, as land was available for the construction of a depot at Mankhurd. The MMRDA approved the detailed project report for the line in August 2015. The report estimated the cost of the project as . On 15 June 2015, the MMRDA announced that it would combine the two stretches and implement the Yellow Line of the Mumbai Metro in three parts - Dahisar East-DN Nagar (Metro 2A), DN Nagar-BKC (Metro 2B), and BKC-Mankhurd (Metro 2C). On 1 July 2015, it was announced that the MMRDA was allotted a plot in
Mankhurd adjacent to the
Sion Panvel highway for the Metro carshed. The land was under dispute between the MMRDA and the State Home Ministry for the construction of a jail. The plan was later modified to build the line in two sections - Dahisar-DN Nagar (Metro 2A) and DN Nagar-Mankhurd (Metro 2B). Metro 2A was approved by the Maharashtra Government on 6 October 2015. In November 2015, the Department of Economic Affairs (DEA) cleared the MMRDA's request to secure a loan from the
Asian Development Bank (ADB). The Maharashtra Cabinet approved the Metro 2B corridor on 27 September 2016. Half of the project cost will be funded by the Centre and the State Government, while the remaining will be financed through loans from the Asian Development Bank and the New Development Bank. The Metro 2B corridor was proposed to be long and to have 22 stations. The project was estimated to cost 10,986 crore, including land acquisition cost of 1,274 crore. A study by
World Resources Institute (WRI) India, published in May 2021, estimated that Metro 2A and Line 7 had the potential to create 1.1 million jobs in the city.
Elevated Metro 2B The elevated Metro 2B line received permission from the
Central Railway (CR) to be built at a height of 22 metres over the
Central Line to accommodate CR's plan to construct an elevated CST-Panvel high-speed rail line and an elevated CST-Kalyan line. The MMRDA objected to the height band due to concerns over difficulty involved in operating a metro line at that height as well as evacuating passengers to ground level in case of an emergency. The Central Railway later granted the MMRDA permission to build Metro 2B at a height of 13 metres, with the CST-Panvel elevated line proposed to take a height of 22 metres. Petitions against the project were also filed in the
Bombay High Court by the Juhu Vile Parle Development Cooperative Housing Association, the Gulmohar Area Society Welfare Group, and the Balabhai Nanavati Hospital. Some Mumbai residents protested the project on 5 October 2017 at Santacruz and Mahim. Several celebrities including Javed Akthar participated in the protest. Metro 2B also faced legal issues concerning the section between Indira Nagar and Nanavati Hospital that passes through a funnel area of the
Juhu Aerodrome. In June 2018, the MMRDA filed an affidavit in the Bombay High Court stating that it had "taken into consideration all the aspects of the project, including the pros and cons of underground and elevated Metro, and have taken a conscious decision to go for an elevated Metro". The agency stated that there was insufficient land available to build the metro partly underground, as large quantities of land were required to build the ramps going underground and coming back overground. The agency also noted that an underground metro would take 2 years to build and would cost over 5.5 times more per kilometer than an elevated line. The MMRDA stated that the design of the metro was a "highly technical issue" and that the petitioners did not have the required scientific experience to evaluate it. In August 2019, the Court directed the petitioners to explain why they thought the MMRDA had selected an elevated line instead of an underground line, after the petitioner's advocate stated that he "had not come prepared" and did not know if there was a scientific reason behind the MMRDA's decision. The Bombay High Court ruled in favour of the MMRDA and dismissed all petitions against the Metro 2B project.
Cancelled stations Two metro stations (MMRDA Station and Kurla Terminus) that were originally proposed for Metro 2B were cancelled. The MMRDA Station was cancelled because it overlapped with the Kalanagar flyover ramp. The Kurla Terminus station was cancelled in September 2020 because it was in the path of the restricted funnel zone for
Mumbai Airport. Further, the proposed SG Barve Marg station was only 474 metres away from the proposed Kurla Terminus. Another issue was that the Kurla Terminus station would have been located between the
Santa Cruz–Chembur Link Road (SCLR) rail overbridge and another permanent structure.
Depot and Line 7 link Line 7 of the Mumbai Metro connects Dahisar East with Andheri East, and the depot for the line was proposed to be located at
Dahisar. However, land acquisition for the Dahisar depot was delayed by litigation filed in 2016. In 2020, the MMRDA proposed using the depot at
Charkop to serve both Line 2A and Line 7 by building a ring metro line to connect the two corridors. The MMRDA utilized an empty plot of land located after Ovaripada station on Line 7 to build pillars for the link connecting the two lines. In November 2021, the MMRDA cancelled the plan to build the depot at Dahisar and instead proposed building the depot for Lines 7, 7A and 9 at Rai Murdhe in Bhayandar. Line 2A and Line 7 were both commissioned on 2 April 2022, with services operating between and
Aarey via
Dahisar East. Both lines were extended on 19 January 2023, providing circular service between and
Gundavali via Dahisar East. The Charkop depot currently serves as the depot for Line 2A and Line 7. The Mandale depot will be used to serve Lines 2A and 2B once completed. ==Construction==