India has recently launched its fourth nuclear-powered ballistic missile
submarine (SSBN), codenamed S4, marking a significant advancement in its
maritime defence capabilities. This launch took place on October 16, 2024, at
the Ship Building Centre in Visakhapatnam, following the commissioning of its
second SSBN, INS Arighat, in August 2024. The third SSBN, INS Aridhaman, is
expected to be commissioned next year.
The S4 submarine boasts nearly 75% indigenous content, showcasing India's growing self-reliance in defence technology.
It is equipped with K-4 ballistic missiles, which have a range of 3,500 km and can be launched through vertical systems. This significantly enhances India's second-strike capability against adversaries like China and Pakistan. INS Arihant is equipped with K-15 SLBMs.
The K-4 and K-15 missiles are both submarine-launched ballistic missiles developed by India, but they differ significantly in terms of range, capabilities, and operational roles.
K-15 Missile
The K-15, also known as Sagarika, has a range of approximately 750 km, making it suitable for targeting adversaries close to India's borders. It is primarily deployed on the INS Arihant-class submarines and is considered a reliable second-strike capability against regional threats like Pakistan and China.
K-4 Missile
The K-4 missile offers a significantly greater range of about 3,000 to 4,000 km, which allows for more strategic flexibility and the ability to target deeper into enemy territory. This missile is intended to enhance India's nuclear deterrence by operationalizing its sea-based nuclear triad. The K-4 can carry a larger payload and features advanced manoeuvrability to evade missile defence systems.
| Feature | K-15 | K-4 |
|---|
| Type | Short-Range Submarine-Launched Ballistic Missile (SLBM) | Intermediate-Range SLBM |
| Maximum Range | 750 km | 3,000 - 4,000 km |
| Payload Capacity | Approximately 1 ton | Up to 2 tons |
| Length | About 10 meters | Approximately 12 meters |
| Development | Indigenously developed by DRDO | Indigenously developed by DRDO |
| Operational Status | Operational since 2018 | Undergoing testing and deployment |
| Launch Mechanism | Vertical launch from submarines | Vertical launch from submarines |
| Manoeuvrability | Limited manoeuvrability | Can perform three-dimensional manoeuvres to evade defences |
The SSBNs are designed for long-term underwater operations, with endurance
limited primarily by food supplies and crew fatigue. They provide a reliable
second-strike capability essential for strategic nuclear deterrence.
The launch of S4 comes amid heightened regional tensions and reflects India's
commitment to bolstering its naval capabilities in response to the increasing
assertiveness of China's military presence in the Indian Ocean. The Indian
government has prioritized the development of nuclear submarines over
traditional aircraft carriers due to their vulnerability to long-range
missiles.
| Submarine Name | Commissioning Date | Missile Type | Range (km) | Indigenous Content |
|---|
| INS Arihant | 2016 | K-15 | 750 | 40% |
| INS Arighat | August 29, 2024 | K-4 | 3,500 | 75% |
| INS Aridhaman | Expected 2025 | K-4 | 3,500 | 75% |
| S4* | October 16, 2024 | K-4 | 3,500 | 75% |
In addition to the S4, India plans to construct two more nuclear-powered
attack submarines and has recently approved the construction of three advanced
diesel attack submarines in collaboration with France. This strategic shift
underscores India's focus on enhancing its maritime deterrence capabilities
against potential threats in the Indo-Pacific region.
The commissioning of the S4* submarine is part of a broader strategy to bolster India's maritime security, particularly in response to increasing naval activities from China in the Indian Ocean. Additionally, the Indian Navy is set to construct two more nuclear-powered attack submarines to further enhance its deterrence capabilities in the region.
Focus On Maritime Security
Defence Minister Rajnath Singh said in a message to the neighbouring countries who share maritime boundaries with India that maritime security is a collective effort and inviting “outside forces” to the doorstep would dent efforts for unity, PTI reported.
“Maintaining peace in the Bay of Bengal and Indian Ocean Region should be top priority. Cooperation of India’s friendly nations is essential in this effort, as even if one country is left out, the nation's security wheel breaks,” Singh said.
The Navy said it has taken several steps to deal with the issue. These measures include:
1. The Indian Navy has substantially enhanced maritime surveillance efforts in the central/north Arabian Sea and augmented force levels.
2. Task Groups comprising destroyers and frigates have been deployed to undertake maritime security operations and render assistance to merchant vessels in case of any incident.
3. Aerial surveillance by long-range maritime patrol aircraft and RPAs has been enhanced to have complete maritime domain awareness.
4. Towards effective surveillance of the Exclusive Economic Zone (EEZ), the Indian Navy is operating in close coordination with the Indian Coast Guard.
5. The Indian Navy is closely monitoring the overall situation in coordination with national maritime agencies. "The Indian Navy remains committed to ensuring the safety of merchant shipping in the region," the navy said.
