Project 77-class submarine
Project 77 is an Indian Navy acquisition programme to procure nuclear-powered attack submarines.
Background
Development
The Government of India, through the Cabinet Committee on Security, approved the construction of six nuclear attack submarines on 18 February 2015. Following the approval, the Naval Staff Qualitative Requirements are to be ascertained for the over 6,000 tonne-displacement submarines. These are to be built at the Ship Building Centre at Visakhapatnam. On 8 December 2017, Navy chief, Admiral Sunil Lanba, announced that the design for the class of six submarines had commenced at the newly commissioned Submarine Design Centre, Gurgaon. The project cost was estimated at. These will be designed by the Navy's in-house Directorate of Naval Design. The construction was expected to commence on 2023–24 while the first submarine is expected to enter service in 2032.On 24 June 2019, it was reported that have been allocated for the initial phase of the project. The development is expected to continue till 2025. Mishra Dhatu Nigam is developing a new hull material that is expected to allow the submarine to dive to deeper depths than. A scaled down model of the submarine is planned to be tested first. The total cost of the project is now estimated to be around.
In February 2020, The Economic Times reported that the preliminary design phase of the programme has been successfully completed. The report stated that Submarine Design Group of the Directorate of Naval Design, assisted by the DRDO, will now start working on the detailed design and construction phase of the programme.
As of March 2021, it was reported that the Indian Navy has prioritised the construction of Project 75 Alpha submarines over a planned third aircraft carrier. Later it was announced that initially, three submarines will be cleared in 2023-24 while the remaining three will get clearance later. The first boat was expected to roll out in 2032. The ship class will have a final design clearance in Gurugram by Submarine Design Group, its nuclear reactor will be built in Kalpakkam, hull fabrication will be undertaken by Larsen & Toubro at Hazira and finally assembly and sea trials will be conducted by the Ship Building Centre in Visakhapatnam.
As of August 2024, a report suggested that the first batch of P-75A class will have 2 submarines, while 4 more will be cleared in a later phase. The final clearance for the 1st batch worth is expected to be received "soon" from the Cabinet Committee on Security.
On 9 October 2024, the CCS cleared the project at to construct 2 nuclear attack submarines for the Indian Navy. The submarines shall be built at Ship Building Centre in Visakhapatnam and will include major private sector firms including Larsen & Toubro. According to reports, the first submarine will take 10–12 years to be launched with a 190 MW pressurised light-water reactor and a displacement of almost 10,000-tonnes. The maximum speed will be over. The submarines will feature an indigenous content of 95% and foreign assistance will include design consultancy only.
During a press conference, the Indian Navy confirmed that it plans to operate 6 SSNs in total. The first of the initial two submarines is to be completed by 2036-37 followed by the next in 2038-39. The submarines are anticipated to be equipped with DRDO-developed hypersonic missiles and an upgraded BrahMos, which might have a strike range of 1,500–2,000 kilometers.
In September 2025, the Times of India reported that the Bhabha Atomic Research Centre is developing a 200 MWe-rated nuclear reactor for the Indian Navy's next-generation nuclear submarines, including Project 77 and S5-class submarines.