Project 77-class submarine. Project 77 (formerly Project 75 Alpha) is an Indian Navy acquisition programme to procure nuclear-powered attack submarines. The Government of India, through the Cabinet Committee on Security (CCS), approved the construction of six of these submarines in February 2015. These will be designed by the Navy's in-house Directorate of Naval Design (now Warship Design Bureau) and built in India at the Ship Building Centre at Visakhapatnam. The construction was expected to commence on 2023-24 while the first submarine is expected to enter service in 2032. However, further and final clearance for initially acquiring 2 nuclear submarines, under the Project 77, was approved by CCS on 10 October 2024.

Since India is a traditional user of Russian nuclear submarines (with INS Chakra on lease) the new domestically built submarines would be third class of SSN operated by Indian navy after leased Charlie I and Akula II-class submarines.

Development
The program to construct and deploy a fleet of nuclear submarines was first envisaged in late 1990s. Patrolling by People's Liberation Army Navy ships further fast-tracked India's naval expansion programmes. As per the initial plan, first 4 Arihant class submarines and later much larger S5 class nuclear ballistic missile submarines, and 6 nuclear attack submarines were planned.

The submarines will be powered by a miniature pressurised water reactor (PWR) being developed by the Bhabha Atomic Research Centre which has already supplied a similar 83 MW miniature reactor for the Arihant-class submarine SSBNs.

On 24 June 2019, it was reported that  have been allocated for the initial phase of the project. The submarines will be designed by Directorate of Naval Design (now called Warship Design Bureau) and 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 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 (SBC) 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 (CCS).

On 9 October 2024, the CCS cleared the project worth  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.

See also
 Submarines of the Indian Navy
 Future of the Indian Navy

References

Nuclear-powered submarines
Submarine classes
Attack submarines
Submarines of the Indian Navy