What is INS Aridhaman? India set to welcome third nuclear-powered ballistic missile Arihant-class submarine

INS Aridhaman dominated social media after Defence Minister Rajnath Singh wrote a cryptic post on Friday, which many claimed hinted at the commissioning of Arihant-class submarine INS Aridhaman.

What did Rajnath Singh post on X?

On the day the India Navy commissioned INS Taragiri, Rajnath Singh took to X to say: “Shabd nahi, Shakti hai ‘Aridhaman’” This translated to: “Not just a word, 'Aridhaman' is power!”

Following Singh's post, news agency ANI claimed that in his X post, Rajnath Singh described the submarine as more than just a name, calling it a symbol of power.

Meanwhile, Union Minister for Communications and Development of North Eastern Region Jyotiraditya Scindia posted on X, “India is set to welcome its 3rd nuclear-powered ballistic missile submarine, INS Aridhaman.”

Reports also emerged suggesting that INS Aridhaman will be commissioned during a ceremony on Friday. However, there was no official confirmation on whether INS Aridhaman was also commissioned, along with INS Taragiri, into the Indian Navy on Friday.

In December 2025, Navy Chief Admiral Dinesh K. Tripathi had announced that INS Aridhaman will be commissioned soon. Speaking at the annual pre-Navy Day press conference, Admiral Tripathi confirmed that the advanced submarine has entered the final stages of its trials, India Today reported.

What is INS Aridhaman?

INS Aridhaman is India’s third indigenously-built nuclear-powered ballistic missile submarine. The fourth nuclear-powered ballistic missile submarine is reportedly designated S4*, with its formal name yet to be announced.

According to ANI, INS Aridhaman is an advanced version of the Arihant-class submarines, following earlier inductions such as INS Arighaat in August 2024 and INS Arihant in 2016.

It's equipped to carry longer-range missiles, significantly strengthens India’s sea-based nuclear deterrence by enhancing both strike capability and survivability in line with the country’s nuclear doctrine.

INS Aridhaman, built under the Advanced Technology Vessel project at the Ship Building Centre in Visakhapatnam, is designated as S4 or SSBN 82, Armyrecognition.com reported.

It added that INS Aridhaman is the third Indian-made nuclear submarine and the second Arihant-class unit.

The submarine was reportedly laid down around 2017 to 2018, launched quietly on November 21 or 23, 2021, and has been undergoing harbour acceptance and sea trials since 2022, with final weapon and reactor checks completed by mid-2025.

Key features, as per Armyrecognition.com

1. INS Aridhaman's displacement is consistently given as about 6,000 tonnes on the surface and approximately 7,000 tonnes submerged, with a complement of roughly 95 to 100 crew members, including officers and sailors.

2. It is powered by an 83 MW CLWR-B1 compact light water pressurised reactor derived from the prototype naval reactor at Kalpakkam, driving a single shaft with a seven-blade propeller.

3. Speed is stated at 12 to 15 knots when surfaced and about 24 knots when submerged.

4. As per the report, the missile and combat system of INS Aridhaman reflects a larger payload than earlier Arihant-class units, with eight vertical launch system (VLS) tubes in the raised hull section compared to four on INS Arihant and INS Arighaat.

5. This arrangement allows the submarine to carry up to 24 K-15 Sagarika submarine-launched ballistic missiles, with a range of about 750 kilometers.

6. Alternatively, the submarine can embark up to eight K-4 SLBMs, with ranges around 3,500 kilometers, and is widely expected to be compatible with future K-5 missiles, which are described as having a range between 5,000 and 6,000 kilometers.

7. The INS Aridhaman also retains a set of six 533 mm torpedo tubes to launch heavyweight torpedoes such as the Varunastra, as well as certain cruise missiles or mines for self-protection and limited conventional strike roles.

India's nuclear attack submarine

India’s first leased nuclear attack submarine, INS Chakra, was designated as S1, leading to the naming of subsequent submarines: INS Arihant as S2, INS Arighaat as S3, and INS Aridhaman as S4, the Hindustan Times reported in October 2024.

The newly launched submarine is designated S4*, with its formal name yet to be announced, it added.

Future classes of Indian SSBNs are expected to have a displacement of 6,000 tons, double that of the Arihant class, and will carry nuclear missiles with ranges exceeding 5,000 kilometers and beyond, reported Hindustan Times.