Arihant-class submarine

Basic information

Type:

Submarine

Operators:

Indian Navy

Country of build:

India

Builder:

Naval Dockyard (Visakhapatnam)

Planned:

Completed:

Ship measurements

Displacement:

6,000 t

Length:

111 m

Beam:

11 m

Draft:

15 m

Machine

Propulsion:

1 * CLWR-B1 pressurized water reactor (83 MW)
1 * shaft

Speed:

15 knots

Submerged speed:

24 knots

Test depth:

450 m

Submerged range:

Unlimited except by food supplies

Personnel

Complement:

Combat assets

Electronics:

USHUS sonar
Panchendriya sonar

Armament:

Arihant & Arighaat:

12 * K15 SLBM (1,500 km or 930 mi range) or 4 * K-4 SLBM (3,500 km or 2,200 mi range)

Aridhaman & S4*:

24 * K15 SLBM (750 km or 470 mi range) or 8 * K-4 SLBM (3,500 km or 2,200 mi range) or 8 * K-5 SLBM (5,000–6,000 km or 3,100–3,700 mi range)
6 * 21" (533 mm) torpedo tubes – est 30 charges (torpedoes, cruise missiles or mines)

The Arihant-class is a class of Indian nuclear ballistic missile submarines under construction for the Indian Navy. They were developed under the US$11 billion Advanced Technology Vessel (ATV) project to design and build nuclear-powered submarines. These vessels are classified as 'strategic strike nuclear submarines' by India.

The lead vessel of the class, INS Arihant was laid down in 2004, launched in 2009 and after extensive sea trials was confirmed to be commissioned in August 2016. Arihant holds the distinction of being the first ballistic missile submarine to have been built by a country other than one of the five permanent members of the United Nations Security Council. As of 25 October 2024, INS Arihant and INS Arighaat are already on deep sea patrols.

The submarines are 111 m (364 ft) long with a beam of 11 m (36 ft), a draught of 15 m (49 ft), displacement of 6,000 tonnes (5,900 long tons; 6,600 short tons). The complement is about 95, including officers and sailors. The boats are powered by a single seven blade propeller powered by an 83 MW pressurised water reactor and can achieve a maximum speed of 12–15 knots (22–28 km/h) when surfaced and 24 knots (44 km/h) when submerged.

The submarines have four launch tubes in their hump and can carry up to twelve K-15 Sagarika missiles with one warhead 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). The third and fourth submarines will have a larger configuration, carrying twenty-four K-15 Sagarika or eight K-4 missiles.

The submarine's K-15 missiles can reach most of Pakistan and its K-4 can target all of Pakistan. The K-4 may also be capable of targeting Beijing, but would need to be in the northern most waters of Bay of Bengal. Deployment of the Arihant to the Pacific Ocean is unlikely given the submarine's noise issues.

K-15 is seen as an interim solution however. Each missile tube should be able to fit a single K-4 missile. The newer K-4 is a full-size SLBM (Submarine Launched Ballistic Missile). This is expected to have a range of around 1,900 nautical miles, almost 4 times that of the K-15. While shorter ranged than the SLBMs in service with more mature nuclear navies, it will move India’s at-sea deterrent up a notch.

The Arihant is a unique design which can be characterized as a ‘pocket boomer’. It is much smaller than other ballistic missile submarines (North Koreas’ conventionally powered boats excepted). Its hull is shorter and thinner than its contemporaries and it only carries four missile silos.

But this does not take away from the industrial achievement of an indigenous nuclear-powered submarine. And in many respects its modest size seems pragmatic. Other countries now taking the nuclear submarine path, such as Brazil, are also going for smaller types.