INS Arisudan

{{Short description|Arihant-class nuclear submarine}} {{use Indian English|date=July 2013}} {{Use dmy dates|date=November 2024}}

{{Infobox ship |section1={{Infobox ship/image | image = Arihant follow on class submarine.jpg | image_caption = A conceptual drawing representing the ''Arihant'' Stretch design }}

|section2={{Infobox ship/career | hide_header = | country = India | flag = {{shipboxflag|India|naval}} | name = INS ''Arisudan'' | ordered = | awarded = | builder = Shipbuilding Centre (SBC), Visakhapatnam, India<ref name="thehindu1">{{cite web|author=S. Anandan|url=http://www.thehindu.com/news/national/second-nuclear-submarine-headed-for-yearend-launch/article2798864.ece|title=Second nuclear submarine headed for year-end launch|work=The Hindu|date=14 January 2012|access-date=2 June 2013}}</ref> | laid_down = 2018<ref name = "hindu1">{{cite news |title=A bigger nuclear submarine is coming |url= https://www.thehindu.com/news/national/a-bigger-nuclear-submarine-is-coming/article19862549.ece |date=2017|website=www.thehindu.com |publisher=The Hindu |access-date=25 June 2025}}</ref> | launched = 16 October 2024<ref> https://www.thehindu.com/news/national/indias-fourth-nuclear-submarine-launched-into-water/article68783731.ece</ref> | christened = | acquired = | commissioned = | recommissioned = | decommissioned = | in_service = | out_of_service = | renamed = | reclassified = | refit = | struck = | reinstated = | homeport = | captured = | fate = | status = Sea trials underway }}

|section3={{Infobox ship/characteristics | hide_header = | header_caption = | class = {{sclass|Arihant|submarine|1}} | type = Nuclear ballistic missile submarine | displacement = 7,000 tonnes | length = 130 m | beam = 11 m | height = | draft = 9.5 m | depth = | decks = | deck_clearance = | power = *1 x CLWR-B1 Compact Light-water reactor,<ref name="CLWR-B1">{{cite news|title=Founder's Day Speech, Director, BARC|url=http://www.barc.gov.in/presentations/fddir18.pdf|access-date=21 March 2021|publisher=Bhabha Atomic Research Centre|date=30 October 2018}}</ref><ref name="clwr_barc">{{cite journal|title=DAE Excellence in Science, Engineering & Technology Awards 2010|journal=BARC Newsletter|date=September–October 2011|issue=322|page=33|url=http://www.barc.gov.in/publications/nl/2011/2011091009.pdf|access-date=21 March 2021|archive-date=15 May 2013|archive-url=https://web.archive.org/web/20130515202113/http://barc.gov.in/publications/nl/2011/2011091009.pdf|url-status=dead}}</ref> 83 MW<ref name="IndiaToday" /> | propulsion = *1 × propeller shaft, nuclear propulsion | speed = '''Surfaced:''' {{convert|12|-|15|kn|km/h}} '''Submerged:''' {{convert|24|kn|km/h}} | range = Unlimited except by food supplies | endurance = Unlimited except by food supply and maintenance | test_depth = Between {{convert|300|m|abbr=on}} to {{convert|400|m|abbr=on}} | complement = | time_to_activate = | sensors = *USHUS sonar *Panchendriya unified submarine sonar, control system and underwater communication system<ref name="naval-technology.com">{{Cite web |url=http://www.naval-technology.com/projects/arihant-class/|title=Retrieved on 2016-10-21.|access-date=29 December 2012|archive-url=https://web.archive.org/web/20130502115614/http://www.naval-technology.com/projects/arihant-class|archive-date=2 May 2013|url-status=live }}</ref> | EW = | armament = * 6 × 21" (533 mm) torpedo tubes – est 30 charges (torpedoes, cruise missiles or mines)<ref name="globalsecurity">{{cite web|first=John|last=Pike|url=http://www.globalsecurity.org/military/world/india/atv-specs.htm|title=Advanced Technology Vessel (ATV)|publisher=globalsecurity.org|date=27 July 2009|access-date=24 January 2011|url-status=live|archive-url=https://web.archive.org/web/20110829062226/http://www.globalsecurity.org/military/world/india/atv-specs.htm|archive-date=29 August 2011}}</ref> *8 VLS cells for either **24 K-15 Sagarika SLBM **8 K-4 SLBM | notes = }} }}'''INS ''Arisudan''''' ('''SSBN 83''') ({{Lit|Slayer of foes}}) is a nuclear-powered ballistic missile submarine, and the fourth and final {{sclass|Arihant|submarine|1}} of the Indian Navy. It is designated '''S4*''' Strategic Strike Nuclear Submarine. The 7,000-tonne vessel was built under the Advanced Technology Vessel (ATV) project at the Ship Building Centre in the port city of Visakhapatnam. It is an upgraded variant of the ''Arihant''-class submarine.<ref>{{cite web|url=http://www.sunday-guardian.com/analysis/needed-a-nuclear-triad|title=Needed, a nuclear triad|publisher=Sunday-guardian.com|access-date=2 June 2013|archive-date=3 May 2014|archive-url=https://web.archive.org/web/20140503233228/http://www.sunday-guardian.com/analysis/needed-a-nuclear-triad|url-status=dead}}</ref><ref>{{cite web|url=http://www.defencenow.com/news/551/india-to-construct-two-more-arihant-nuclear-submarines-for-navy.html|title=India To Construct Two More Arihant Nuclear Submarines For Navy|publisher=Defence Now|date=28 February 2012|access-date=2 June 2013|archive-url=https://web.archive.org/web/20150712032120/http://www.defencenow.com/news/551/india-to-construct-two-more-arihant-nuclear-submarines-for-navy.html|archive-date=12 July 2015|url-status=dead}}</ref>

== Description == The boat will have one seven-blade propeller powered by a Compact Light Water Reactor (CLWR). It can achieve a maximum speed of {{convert|12|-|15|kn|km/h}} when on surface and {{convert|24|kn|km/h}} when submerged.<ref name="navaltech">{{cite web |url= http://www.naval-technology.com/projects/arihant-class/ |title=SSBN Arihant Class Submarine, India |publisher=naval-technology.com |access-date=2 June 2013}}</ref><ref>{{Cite web |date=31 August 2024 |title=INS Arighaat: How a second nuclear submarine boosts India’s strategic reach |url=https://www.indiatoday.in/india/story/ins-arighaat-how-a-second-nuclear-submarine-boosts-indias-strategic-reach-2591300-2024-08-31 |access-date=10 September 2024 |website=India Today |language=en}}</ref><ref>{{Cite web |date=22 December 2020 |title=India to commission second Arihant-class submarine in 2021 |url=https://www.janes.com/osint-insights/defence-news/india-to-commission-second-arihant-class-submarine-in-2021 |access-date=10 September 2024 |website=Default |language=en}}</ref> The CLWR is an upgraded form of the one that powers INS Arihant. The CLWR has exceptionally lower acoustic signature than the previous generation making it harder to detect by enemy vessels along with longer endurance.<ref>{{Cite web |date=8 September 2024 |title=How Refined 83 MW PWR on INS Arighat Boosts its Stealth and Endurance Compared to INS Arihant |url=https://defence.in/threads/how-refined-83-mw-pwr-on-ins-arighat-boosts-its-stealth-and-endurance-compared-to-ins-arihant.9797/ |access-date=10 September 2024 |website=Defence.in |language=en-US}}</ref>

The submarine has eight VLS tubes in its hump, as compared to four on her predecessors— She can carry up to 24 K-15 Sagarika missiles (each with a range of {{convert|750|km|abbr=on|disp=or}}), eight K-4 missiles (with a range of {{convert|3500|km|abbr=on|disp=or}}) or K-5 missiles (with range of 6,000 km or 3,700 mi).<ref name="IndiaToday">{{cite news|url=https://www.indiatoday.in/magazine/the-big-story/story/20171218-india-ballistic-missile-submarine-k-6-submarine-launched-drdo-1102085-2017-12-10|title=A peek into India's top secret and costliest defence project, nuclear submarines|date=7 December 2017|work=India Today|access-date=11 December 2017|url-status=live|archive-url=https://web.archive.org/web/20190420153439/https://www.indiatoday.in/magazine/the-big-story/story/20171218-india-ballistic-missile-submarine-k-6-submarine-launched-drdo-1102085-2017-12-10|archive-date=20 April 2019}}</ref><ref>{{Cite web|url=https://www.indiatoday.in/india/story/ins-arihant-returned-yesterday-from-20-day-deterrent-patrol-1383188-2018-11-05|title=INS Arihant returned yesterday from 20-day deterrent patrol|date=5 November 2018|website=India Today|language=en|access-date=13 October 2019}}</ref><ref>{{Cite news |date=2024-11-28 |title='Nuclear-capable ballistic missile tested from INS Arighaat' |url=https://timesofindia.indiatimes.com/india/nuclear-capable-ballistic-missile-tested-from-ins-arighaat/articleshow/115747030.cms |access-date=2024-11-30 |work=The Times of India |issn=0971-8257}}</ref>

== Construction == Around 2012, the S5 submarine project to succeed and supplement the first three ''Arihant'' class submarines remained in the developmental stage. Hence, another ''Arihant''-class submarine was cleared for production as a stopgap measure<ref name=":18">{{Cite web |date=2025-12-29 |title=CHAKRA EXCLUSIVE: India's fourth SSBN sails out for sea trials |url=https://chakranewz.com/critical-technologies/trending/chakra-exclusive-india-rsquo-s-fourth-ssbn-sails-out-for-sea-trials |access-date=2025-12-30 |website=chakranewz |language=en}}</ref> to avoid idling of the production line.

The newly designated S4* submarine will be fourth and final submarine of the class, with an indigenous content of over 80%<ref name=":18" /> and equipped with K4 missiles, was thereafter launched on 16 October 2024.<ref name=":8">{{Cite news |last=Gupta |first=Shishir |date=22 October 2024 |title=India Launches 4th nuclear-missile submarine |url=https://www.hindustantimes.com/india-news/india-launches-4th-nuclear-missile-submarine-101729560730642.html |access-date=22 October 2024 |work=Hindustan Times}}</ref> By December 2025, the submarine entered sea trials. During the fourth week of the month, the vessel sailed out from her berth at the Shipbuilding Centre.<ref name=":18" /><ref name=":19">{{Cite web |last=Militar |first=Redaccion Zona |date=2025-12-30 |title=India is reported to have begun sea trials of the fourth of its new Arihant-class nuclear-powered ballistic missile submarines |url=https://www.zona-militar.com/en/2025/12/30/india-is-reported-to-have-begun-sea-trials-of-the-fourth-of-its-new-arihant-class-nuclear-powered-ballistic-missile-submarines/ |access-date=2025-12-31 |website=Zona Militar |language=en-US}}</ref>

== Naming == The submarine was designated as S4*, as it was an follow on order to the previous class and will be built before the tentative S5 class submarines.<ref>{{Cite web |last= |first= |date=2024-08-29 |title=INS Arighaat: How India’s 2nd nuclear submarine is major defence boost {{!}} 5 points |url=https://www.hindustantimes.com/india-news/ins-arighaat-how-india-s-2nd-nuclear-submarine-is-major-defence-boost-explained-101724938709013.html |access-date=2026-05-20 |website=Hindustan Times |language=en}}</ref><ref>{{Cite news |last=Bhattacharjee |first=Sumit |date=2026-04-03 |title=INS Aridhaman, nuclear-powered submarine, enters India’s naval fleet |url=https://www.thehindu.com/news/national/indias-new-nuclear-powered-submarine-ins-aridhaman-commissioned/article70819744.ece |access-date=2026-05-20 |work=The Hindu |language=en-IN |issn=0971-751X}}</ref> The new unit designated as S4* would feature the stretched configuration of the third submarine of the class, {{INS|Aridhaman}}.<ref name="India Today3">{{cite news |last=Unnithan |first=Sandeep |date=7 December 2017 |title=A peek into India's top secret and costliest defence project, nuclear submarines |url=https://www.indiatoday.in/magazine/the-big-story/story/20171218-india-ballistic-missile-submarine-k-6-submarine-launched-drdo-1102085-2017-12-10 |url-status=live |archive-url=https://web.archive.org/web/20171211024434/http://indiatoday.intoday.in/story/india-ballistic-missile-submarine-k-6-submarine-launched-drdo/1/1104982.html |archive-date=11 December 2017 |access-date=11 December 2017 |work=India Today}}</ref> S4* could be commisioned in late 2027 and would enable Countinnues at-sea deterrance. The submarine may also take upp the pennent number S76. The submarine will be initially homeported in Visakapatnam before moving to INS Varsha.<ref>https://www.iiss.org/online-analysis/military-balance/2026/05/deepening-deterrence-indias-expanding-ssbn-capability/</ref>

It was also reported in January 2026, that the final submarine, so far referred to as S4*, will be named INS ''Arisudan'' upon entry into service. The name has been proposed by the ship-naming committee of the Indian Navy and is yet to be receive clearance by the defence ministry and eventually, the President of India, who is also the Supreme Commander of the Armed Forces.<ref name=":20">{{Cite web |date=2026-01-05 |title=Arihant class nuclear-powered submarine S4* likely to be named INS Arisudan |url=https://www.hindustantimes.com/india-news/arihant-class-nuclear-powered-submarine-s4-likely-to-be-named-ins-arisudan-101767555406284.html |access-date=2026-01-05 |website=Hindustan Times |language=en}}</ref><ref>https://drdo.gov.in/drdo/sites/default/files/drdo_news/NPC03to05Jan2025.pdf</ref><ref>{{Cite web |last=Bedi |first=Rahul |title=India Builds Nuclear-Powered Submarines with Ease, but Stalls on Less Complex Fleet |url=https://thewire.in/security/india-builds-nuclear-powered-submarines-with-ease-but-stalls-on-less-complex-fleet |access-date=2026-05-20 |website=The Wire |language=en}}</ref>

== See also == * Future of the Indian Navy * K Missile family

==References== {{reflist|colwidth=30em}}

{{Submarines of the Indian Navy}}

{{DEFAULTSORT:Arisudan}} Category:Arihant-class submarines Category:Nuclear-powered submarines Category:Ships built in India Category:Submarines of India Category:2021 ships Category:Submarine classes