SSBN Aridhaman – Vanquisher of Foes

Col Alok Mathur, SM (retd)

It was a proud memorable moment for the nation , when SSBN Aridhaman, indigenously built third nuclear powered ballistic missile Submarine was commissioned in to the  Indian Navy at Vishakhapatnam Naval base in Andhra Pradesh on Friday 02 April 2026.The induction of  new Nuclear powered U Boat will big boost to nuclear triad capability of Indian Armed forces multifold.

INS  Aridhaman, which literally means ’ Vanquisher of Foe’ , Code  Name S 4, joined Indian Navy in presence of Raksha Mantri Rajnath Singh, Naval Chief Admiral Dinesh K Tripathi, Chairman DRDO , Scientists of BARC and Engineers of NSTL and staff of Ship building Centre , VIZAG. The violent waves of Bay of Bengal warmly accepted the new baby in her folds. INS Aridhaman is an upgraded version of Arihant class of SSBNs and joins the Arihant club of two more sisters SSBNS (Arihant and Arighat)

SSBN acronym means Ship Submersible Ballistic Nuclear or in simple terms a manned submarine fitted with nuclear reactor as power plant and equipped with Ballistic Missiles with Nuclear Warhead. It can operate underwater for months together self contained without surfacing and travel round the world.

INS Aridhaman is the marvel product of Advance Technology Vessel (ATV) project of Naval Science and Technology Lab  (NSTL) of  DRDO conceived in 1984.The keel of S 4 was laid in 2018 and the vessel assembly was completed 23 Nov 2021. Intensive Sea trial including firing continued for two years. CNS announced on 2 Dec 2025 that High Sea trials had been successfully completed and it was finally operational on 3 April 2026. The third SSBN has displacement of 7000 tonnes (more than 1000 tonnes from her predecessors) 130 metre long, 12 metre wide and 10 metres high. The hull is made of Titanium alloys and carbon fibre. It has submerged cruising speed of 50 kms per hour (3O knots). The crew consists of 100 officers and ratings. The power pack is one CLWR 81 (Compact Light Water nuclear reactor) heavy water cooled  capable of 83 MW power generation. It is fitted with I X nuclear powered 7 blade shaft for propulsion. The range of the SSBN Aridhaman is unlimited but restricted by food supplies and periodic maintenance. The eyes of Submarine are based on USHUS sonar sensors system developed by Naval Physical and Oceanographic Lab (NPOL) and produced by BEL and ears are based on Panchendriya unified integrated and communication systems, which keeps it in communication with Base Headquarters and outside world. SSBN Aridhaman has advanced Stealth features due to advanced silent CLWR power pack with very low acoustic signatures and carbon composite material   used in hull also reduces physical signatures for enemy detection. The firepower and Lethality of SSBN S4 has been considerably enhanced compared to other two SSBNs. INS Aridhaman, is equipped with 8 Vertical Launching System ( VLS) Tubes. SSBN Arihant and SSBN Arighat had only Four VLS tubes. The SSBN    S 4 can carry 24 x K 15 (Sagarika missiles Range 750 kms) or 8 x K 4 ( Kalam Range 4000 kms) tipped with Nuclear and conventional Warheads. K 5 IRBM with range 6500 kms also under development. Accordingly, Entire Asia, Eastern Africa and Europe will be in striking range of our SSBN Fleet.

INS Arihant Code name S 2  ( meaning Conqueror of Enemy ) was the first SSBN of Indian Navy .The keel was  laid in 2004 and was launched in 2009 . It completed Sea trials in 2013 and finally commissioned in Indian Navy on 15 Aug 2016. It had displacement of 6000 tonnes, 111 metre long, 15 metres beam and draft of 11 metres. It was powered by 1x CLWR 81 nuclear reactor built by Bhabha Atomic Research Centre ( BARC). It was equipped with 4 Vertical launch tubes (VLS) for firing K 15/ K 4   Submarine launched Ballistic missiles. It could carry 12 x K 15 or 4 X K 5 missiles on board. Its alternative weapon system has 6x 533mm torpedo tubes fitted with Anti ship Varunastra. It had unlimited range and could dive up to 300 metres. It was a technology demonstrator model with double hull constructed by Larsen and Tourbo. Tata power Strategic Engineering Division built the control system for the vessel. SSBN 80 is fully operational as on date,

SSBN Arighat  Code Name S 3  ( meaning Destroyer of Enemy )  was the indigenously built second Nuclear Powered Submarine equipped with Nuclear tipped Ballistic Missiles (SSBN) Joined Indian Navy on 28 August 2024 in presence of Raksha Mantri Raj Nath Singh, Chief of Defence Staff and CNS. SSBN Arighat fully  designed and manufactured in India , a matter of proud for the Nation and dream of Atma Nirbhar Bharat. The Indian SSBN is  weighing about 6000 tonnes , 112 metre Long  and about 11 Metres wide and 10 metres High Hull of Titanium based alloys with  submerged cruising speed is almost 50  Kilometre per hour (30 knots).The crew consisted of 90 Officers and Ratings.  The scientists of Defence Research and Development Organisation,Naval Science and Technology Lab , Bhabha Atomic Research Centre and  Chairman of Ship Building Centre with  his core Team  , who  were overwhelmed when they also witnessed the  smooth slide of Black Shark INS Arighat with Tricolour painted on Head and Hull  in to  waves of Bay of Bengal . The Lethal Cigar Shaped Black U Boat had become part of Strategic Forces Command to further strengthen the TRIAD capability and strategic deterrence of India against to two Rogue Nuclear neighbours. SSBN 81 is also active and operational.

Shan No Varunah  is the motto of Indian Navy  which means” O God of the Sea ( Varun Devta), be auspicious on us”. Indian Navy is one the top Navies in the World with Blue Water Capabilities. The President of India is the supreme commander of Indian Armed forces. Admiral Dinesh kumar Tripathi, a four star Admiral is the Present Chief of Naval Chief. Indian Navy,s role is to protect the 7000 kms long Blue frontiers and faraway maritime assets in Bay of Bengal , Arabian Sea and Indian Ocean.  It is also mandated to actively participate in Anti Piracy operations in Persian Gulf, Red Sea, Mediterranean Sea, Cape of Good hope and also Malacca strait region and South China Sea also.  India Navy was raised on 26 Jan 1950 and was born from Royal Indian Navy of pre independence era. The present manpower Indian Navy is 1. 5 Lakhs personnel including Reservists.The Navy has approximately 22O Naval Vessels including Modern Aircraft Carriers , Submarines ,Destroyers ,Frigates , Corvettes, Landing Ship Tanks ( LSTs) , Landing Craft Utility (LCU) , Fleet  Tankers, Mine sweepers, Fast patrol boats and several Indian Naval Air Squadrons with modern Fighters like MIG 29K , Deep Surveillance squadrons with P 8I Boeing  , Dornier 228  and Helicopters  Units of Dhurv (ALH), Ka 31 , Sea King Mk 42 C and UH 3 and old Sea horse Chetak. 26 X Rafales Marine Fighter Jets with France  deal worth 63,000 crores was  signed on 24 April 2025 for INS Vikrant.

Submarines are the eyes, ears and teeth of any Navy in the World. German U boats had sunk hundreds of Warships of Allies (USA, Britain, France , Canada) and were terror .Similarly ,Japanese Navy was also very strong and had large fleet of Aircraft Carriers and Submarines and ruled the Indo Pacific waters.  USA and Britain also had a lethal and potent Submarine fleet .

Indian Navy has been also upgrading its Submarine Fleet gradually. As on date, we have a small fleet of approx 20 U boats. Most of the fleet is of Old vintage but after 2015 , there has been focus to replace / upgrade the conventional vintage submarines to Modern and more lethal SSN and SSBN class of Submarines equipped with a small nuclear reactor as power pack which imparts month long underwater duration and inherent safety and security with stealth and unlimited range.

There are three types of Submarines .First type are Diesel Electric Submarines (SS) are the most common conventional type of  Submarines. They are powered by large number of Rechargeable batteries. They are fitted with Diesel power pack with 1000 to 1200 HP and give drive to mechanical robust propellers. 95% of Indian Submarines are conventional submarines .The advantages of this type are that they have low cost of manufacture , easy to maintain and refurbish ,  Radiation free , Safe , whereas the disadvantages are Easy to target as Noisy , have to surface within 72 hours as oxygen required for batteries and less endurance compare to SSN and SSBN . They are tactical Battle platforms. They are fitted with 12/16 Torpedoes with limited range with conventional War heads .India posses 17 conventional Attack Submarines. They are three types of conventional Indian Submarines as per OEM  ie Kalvari Class ( French origin Scorpene ) 05 Nos, Sindhughosh ( Russian Origin Kilo Class) 07 Nos and Shishumar ( HDW German Origin Type  209/1500 ) 04. Russian origin  Submarines are almost 20 years old and  require extensive periodic maintenance. The maximum depth these submarines dive is limited to 200 metres.

Indian Navy romance with Nuclear Submarines dates back to 1984, when Project Advance Technology Vessel (ATV) was sanctioned. India acquired a Charlie class SSN, a nuclear powered submarine from Russia in 1987 and named it as INS Chakra 1 . This was used for training of scientists and designers of DRDO and also for training of crews in nuclear environment. It was returned to Russia in 1991. Again , After lot of negotiations, India was acquired one Akula Class Nuclear powered attack submarine from Russia (SSBN) in 2012 but without any Nuclear tipped/ Conventional weapons. It was named INS Chakra 2. The rider was it could only be used for Reconnaissance and Training purpose only. The main objective was to train Submariners to operate nuclear powered Submarines and train for long under water duration and Nuclear Warfare and learn Anti radiation safety measures. The Vessel was reverted to Russia in June 2021.  Project ATV was already in pipe line to construct SSBNs at Home. DRDO and Naval scientist had already developed a design and process to manufacture at Ship Building Centre Vizag , had already initiated. INS Chakra was leased for 10 years . More than 300 Naval crew were trained during this period. The negotiations  have been finalised  for  leasing another Akula class ( K-322 Kashalot ) SSN, displacement 15,000 tonnes from Russia in 2026 for 10 years. This will be christened as INS Chakra 3 with an aim to construct bigger size SSBNS.

The main Weapon system used by Submarines is Torpedoes. They are conventional   underwater missiles self propelled fitted with High Explosive warheads. They are optically aimed and tracked at the Target. Once launched will move towards target but mid course correction not possible and will explode on Impact/ proximity. They follow the acoustic signatures of Enemy Vessel. French Exocet are very effective Torpedoes. Conventional Submarines have Mine Laying Capabilities also. Indian Arihant Class Submarines will be fitted with four Vertical Launch Cells for 12 X K 15 and 6X 533mm Torpedo Tubes  ( Sagarika) Nuclear warhead Missiles with about 750 to 1000 km range . Arighat and Aridhaman had been  fitted with Kalam 4 Nuclear Missile with a range of 3000 plus kms .Longer Range K 5 with range of 5000 kms also under development which would cover entire Asia and part of Europe.

Indian Government has already approved various Submarine Projects. Four Arihant class SSBNs under Project 76 ( THREE  already commissioned , one under construction) , Six  Nuclear powered submarines SSNs with conventional War heads ( Project 77) , 13 Conventional  foreign origin Submarines under Project 75  and  Seven  under Project 75 I ( Indigenous design) and to be manufactured in India.

Presently, 42 Countries of the World are operating conventional Submarines There are only five nations operating SSBN ( Nuclear powered  submarines equipped with Nukes) .USA , Great Britain, Russia, France and China are old members of the SSBN Club and India  has made a forced entry and Joined the Elite club  in 2016 with  SSBN Arihant, SSBN Arighat in 2024 and  SSBN Aridhaman in 2026.  The trio of three predators are patrolling the Indian maritime frontiers for any hostile intruders continuously. During Op Epic Fury , US SSBNs operated in , Gulf , Arabian Sea  and Indian Ocean boldly and sunk many Warships of Iran . SSBNs are the Silent Sharks who destroy the foe ruthlessly without a warning.