India's indigenous nuclear attack submarine (SSN) program, under the designation Project-77 (formerly Project-75 Alpha), represents a significant step in advancing the nation's naval capabilities. Approved by the Cabinet Committee on Security, the project aims to design and construct six nuclear-powered attack submarines, with the first two currently under development.

The design phase is expected to take 4-5 years, followed by another five years for construction. This timeline places the delivery of the first submarine by 2036-37, with the second expected by 2038-39. 

These submarines will feature 95% indigenous content, reducing dependency on foreign suppliers, while foreign assistance will be limited to design consultancy. The submarines will be equipped with a 190 MW pressurised light-water reactor, have a displacement of approximately 10,000 tons, and achieve speeds exceeding 30 knots.

These SSNs are critical for India's maritime strategy, especially in the Indo-Pacific region. Unlike conventional submarines, nuclear-powered attack submarines have unlimited underwater endurance, limited only by crew requirements. They will be capable of anti-surface and anti-submarine warfare and land-attack missions using cruise missiles.

The program is also expected to galvanise India's defence ecosystem, involving major private sector firms like Larsen & Toubro for hull fabrication and assembly at the Ship Building Centre in Visakhapatnam. The initiative underscores India's commitment to achieving strategic autonomy in defence manufacturing.

Indigenous Design

The Directorate of Naval Design, now known as the Warship Design Bureau, plays a pivotal role in India's Project 77, which aims to develop indigenous nuclear attack submarines. Here are the key responsibilities of the Directorate in this project:

Design Leadership

The Directorate is responsible for designing the submarines, leveraging its expertise in naval architecture and engineering to create a robust and efficient design for the SSNs.

This includes developing the overall layout, ensuring structural integrity, and optimising performance characteristics such as speed and stealth.

Collaboration With Other Agencies

The Directorate works closely with other agencies like the Defence Research and Development Organisation (DRDO) and the Bhabha Atomic Research Centre (BARC) to integrate advanced technologies and systems into the submarine design.

This collaboration is essential for incorporating the new 190 MW nuclear reactor and other sophisticated systems.

Detailed Design Phase

After completing the preliminary design phase, the Directorate moves on to the detailed design phase, which involves refining the design to meet specific operational requirements and ensuring that all systems are fully integrated.

This phase is critical for ensuring that the submarines meet the Indian Navy's strategic needs.

Incorporating Strategic Requirements

The Directorate ensures that the submarine design aligns with India's evolving strategic requirements, including the ability to carry advanced missile systems and enhance the country's nuclear deterrence capabilities.

Directorate of Naval Design is central to the development of Project-77, providing the foundational design expertise necessary for building India's first indigenous nuclear attack submarines.

Designing indigenous nuclear attack submarines poses several key challenges for India:

Technological Hurdles in Nuclear Reactor Design

Developing a reliable and efficient nuclear reactor is crucial. India has faced challenges in producing a viable reactor design, which has led to delays in past projects like the Arihant-class submarines.

The new 190 MW reactor for Project 77 requires significant advancements in design and engineering to accommodate its increased power output and size.

Hull Design And Structural Modifications

The larger reactor necessitates a new hull design with increased internal space and structural modifications. This requires expertise in hydrodynamics and materials science to ensure stealth and survivability.

The Arihant-class submarines were initially designed as SSNs but were modified for SSBN roles, highlighting the complexity of adapting designs for different roles.

Indigenous Content And Dependency On Foreign Assistance

Achieving high indigenous content (95%) while ensuring quality and performance is a challenge. Limited foreign assistance is available, mainly for design consultancy, which means relying heavily on domestic expertise.

Balancing indigenous development with the need for international collaboration for critical technologies can be complex.

Infrastructure And Operational Readiness

Developing robust infrastructure for training, maintenance, and repair is essential for operational readiness. Past accidents, like the one on INS Arihant, underscore the need for reliable systems and trained personnel.

Ensuring that the submarines can operate effectively requires extensive operational experience and confidence-building measures.

Integration of Advanced Systems

Incorporating advanced systems such as hypersonic missiles and silent propulsion technologies (e.g., Nuclear-Electric Propulsion) requires significant design and integration efforts. This involves not only technical capability but also strategic planning to ensure these systems enhance the submarine's overall performance and stealth.

IDN