Indigenous Nuclear Attack Submarines (SSNs)

Sub : Sci

Sec: Defence

Why in News

India’s indigenous nuclear attack submarine (SSN) program has gained attention following approvals for its design and construction phases. The timeline indicates the design phase will take 4-5 years, with the first submarine expected to be ready by 2036-37. This milestone follows India’s experience with ballistic nuclear missile submarines (SSBNs) and recent advancements in submarine technology.

About Nuclear Submarines:

SSNs have infinite capacity to stay dived. As they are not propelled by batteries, they need not emerge for charging by a diesel engine.
Propelled by a nuclear-powered engine, these submarines only need to come to the surface for replenishing supplies for the crew.
SSNs are also able to move faster underwater than conventional submarines. All this allows a navy to deploy them at farther distances, and quicker. They are like the fighter jets of the underwater world.
India is among six nations that have SSNs, alongside the US, the UK, Russia, France and China.
India got its first SSN in 1987 from the Soviet Navy, which it rechristened INS Chakra, which was decommissioned in 1991.
In 2012, India got another Russian SSN on a ten-year lease, called INS Chakra 2, which has since been returned to Russia.
The government has also decided that of the 12 submarines to be built indigenously after the P75 and P75i projects, six would be SSNs instead of SSK.
Types of nuclear submarines:
- Ship Submersible Nuclear (SSN): one that carries conventional weapons.
- Guided Missile Submarines (SSGN): capable of carrying guided missiles with conventional warheads.
- Ship Submersible Ballistic Nuclear (SSBN): can carry ballistic missiles that may be nuclear armed.

About INS Aridhman (S4*):

India’s fourth SSBN, the S4*, was launched into water at the SBC in Visakhapatnam.
It has significant indigenous content, showcasing the involvement of Indian industry in its construction.
It has a submerged displacement of around 7,000 tons, which is larger than its predecessor, INS Arihant, and allows for the inclusion of advanced systems.
The submarine will carry the K-4 submarine-launched ballistic missile (SLBM) with a range of 3,500 km, crucial for India’s undersea nuclear deterrence.
The S4* forms a key part of India’s nuclear triad, enabling second-strike capability from underwater, significantly boosting India’s strategic defence posture.
It is one of the latest in a line of advanced SSBNs under construction, with plans to eventually integrate the K-5 SLBM, extending the strike range to 5,000 km

About INS Arihant (S2):

It has a displacement of 6,000 tonnesand is powered by an 83 MW pressurised light-water reactor with enriched uranium.
Retains the same reactor and dimensions, but has several technological upgrades.
The advanced technology project began in the 1980sand its first product, the Arihant vessel, was launched in 2009 by then-Prime Minister Dr. Manmohan Singh, and eventually commissioned in 2016.
The third of these submarines, which is at an advanced stage of construction, is set to be larger and more capable than the current two submarines in the same class.

About INS Arighaat (S3):

INS Arighaat is a 6,000-tonne Arihant-class ballistic missile submarine.
Arighaat will be armed with indigenously built K-15 missiles, with a range of more than700km.
It can reach a speed of 12–15 knots (22–28 km/h) on the surface and up to 24 knots (44 km/h) when submerged.
It is powered by 83 MW pressurised light-water nuclear reactors, which allow it to remain submerged and undetected for much longer than conventional diesel-electric submarines.
Compared to Arihant, the indigenisation content has doubled in Arighaat (from 30% to 60%)
INS Arighaat will enhance the Navy’s nuclear strike capability and will serve as a vital component of India’s nuclear triad.
Arighaat adds to India’s sea-based nuclear deterrent, which is the most credible and survivable leg of the nuclear triad.