INS Arighaat

INS Arighaat (SSBN 81) (lit. 'Vanquisher of the Enemy') is the second of the Indian Navy's Arihant-class submarine. It is designated S3 Strategic Strike Nuclear Submarine. The 6,000 tonne vessel was built under the Advanced Technology Vessel (ATV) project at the Ship Building Centre in the port city of Visakhapatnam.^[9][3]

An artist's impression of an Arihant-class submarine
History
India
Name	INS Arighaat
Builder	Shipbuilding Centre (SBC), Visakhapatnam, India[1]
Laid down	2011[2]
Launched	19 November 2017[3]
Commissioned	29 August 2024
Status	In active service
General characteristics
Class & type	Arihant-class ballistic missile submarine
Type	Ballistic missile submarine
Displacement	6,000 tonnes
Length	111.6 m
Beam	11 m
Draft	9.5 m
Installed power	1 x CLWR-B1 Compact Light-water reactor,[4][5] 83 MW[3]
Propulsion	1 × propeller shaft, nuclear propulsion
Speed	Surfaced: 12–15 knots (22–28 km/h) Submerged: 24 knots (44 km/h)
Range	Unlimited except by food supplies
Endurance	Unlimited except by food supply and maintenance
Test depth	Between 300 m (980 ft) to 400 m (1,300 ft)[6]
Sensors & processing systems	USHUS sonar Panchendriya unified submarine sonar, control system and underwater communication system [7]
Armament	6 × 533 mm (21 in) torpedo tubes - estd. 30 charges (torpedoes, missiles or mines) 4 VLS cells for 12 × K-15 Sagarika SLBM (or) 4 × K-4 SLBM [8]

The submarine was quietly launched in 2017 and little has been publicly announced about its capabilities and current status. The submarine was originally known as INS Aridhaman but was renamed INS Arighaat upon its launch. Arighaat was commissioned on 29 August 2024.^[10]

Description

The boat will have one seven-blade propeller powered by a Compact Light water reactor (CLWR). It can achieve a maximum speed of 12–15 knots (22–28 km/h) when on surface and 24 knots (44 km/h) when submerged.^[11][12][13] 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.^[14]

The submarine has four launch tubes in its hump, just like her predecessor. She can carry up to 12 K-15 Sagarika missiles (each with a range of 750 km or 470 mi), or four K-4 missiles (with a range of 3,500 km or 2,200 mi).^[3][15][16]

Status

INS Arighaat was launched in November 2017.^[3] INS Arighaat was expected to be commissioned in 2021.^[3][17] However the commissioning was pushed to 2024 as per a report in the Hindustan Times.^[18][19] INS Arighaat has been commissioned on 29 August 2024 after extensive trials and upgrades. The commissioning ceremony was held in the presence of Defence Minister Rajnath Singh in Naval Dockyard at Visakhapatnam.^[20][21][22]

INS Arighaat is significantly more advanced than the INS Arihant with an increased indigenous content of 70%. In contrast to its predecessor which is equipped with only 750-km range missiles, Arighaat is equipped with both K-15 Sagarika and K-4 missiles.^[23]

Service history

On 27 November 2024, a nuclear-capable K-4 SLBM with a range of 3,500 km (2,200 mi) was tested from INS Arighaat in Bay of Bengal. The missile was tested without a warhead and this was the first submarine launch of the long range missile system.^[24][25][26] While the missile launch was a success, the other parameters for the missile test is being examined as of 2 December.^[27]