UPSC Courses

DNA banner


  • 18 July, 2022

  • 15 Min Read



The Navy Kilo Class Submarine INS Sindhudhvaj was decommissioned from service at Visakhapatnam after 35 years in service, the navy now has 15 conventional submarines in service.

About Sindhudhvaj

  • Commissioned into the navy in June 1987, Sindhudhvaj was one of the 10-kilo Class Submarines that India acquired from Russia between 1986 and 2000.
  • The Sindhughosh submarines, designated as 877EKM, were designed as part of Project 877 and built under a contract between Rosvooruzhenie and the Ministry of Defence (India).
  • The submarines have a displacement of 3,000 tonnes, a maximum diving depth of 300 meters and a top speed of 18 knots, and can operate solo for 45 days with a crew of 53.
  • Sindhudhvaj had many first credits, including operationalization of the indigenized sonar USHUS, indigenized satellite communication system Rukmani and MSS, inertial navigation system and indigenized Torpedo fire control system.
  • Sindhudhvaj also successfully undertook matting and personnel transfer with a deep submergence rescue vessel and was the only submarine to be awarded the Chief of Naval Staff (CNS) Rolling Trophy for innovation by Prime Minister Narendra Modi.

A submarine is a watercraft capable of independent operation underwater. India's submarine fleet is based at two locations one is at Visakhapatnam on the east coast and another in Mumbai on the west coast.

Other Submarines of India

  • Number of Submarines in India:

Currently, India has now 15 conventional diesel-electric submarines, classified as SSKs, and two nuclear ballistic submarines which are classified as SSBNs. Most of India’s submarines are over 25 years old, and many are getting refitted.

15 SSKs submarine can be classified as:

  • Four are Shishumar Class, which were bought and then built in India in collaboration with the Germans starting 1980s,
  • Eight are Kilo Class or Sindhughosh Class bought from Russia (including erstwhile USSR) between 1984 and 2000, and
  • Three are Kalvari Class Scorpene submarines built at India’s Mazagon Dock in partnership with France’s Naval Group, earlier called DCNS.

Facts about India’s submarine acquisition

  • India got its first submarine, INS Kalvari of the Foxtrot Class, from the USSR in December 1967.
  • Russia offered India its Kilo Class submarines. Subsequently, India added to its submarine fleet with the help of Russia and Germany.
  • Last year India gifted INS Sindhuvir to Myanmar.
  • In 2012, India got another Russian SSN on a ten-year lease, called INS Chakra 2, which has since been returned to Russia.

About Kalvari Class Scorpene Submarine

  • Kalvari-class Diesel Electric attack submarine was built at Mazgaon Dock in Mumbai on Thursday. They are a stealthy class of submarines having been built under Project 75 and whose design is based on the Scorpene class of submarines.
  • This class inclides INS Kalveri, INS Khanderi, INS Karanj, INS Vela, INS Vagir and INS Vagsheer. Of these Kalvari and Khanderi have been commissioned in 2017 and 2019, Vela and Karanj and undergoing sea trials, Vagir has been launched and Vagsheer is under construction.
  • This class of submarines have Diesel Electric transmission systems and these are primarily attack submarines or ‘hunter-killer’ type which means they are designed to target and sink adversary naval vessels.
  • The Kalvari class of submarines are capable of carrying anti-warships and anti-submarine operations and launching various types of torpedoes and missiles and are equipped with a range of surveillance and intelligence gathering mechanisms.
  • These submarines are around 220 feet long and have a height of 40 feet. It can reach the highest speeds of 11 knots when surfaced and 20 knots when submerged.
  • The modern variants of the Scorpene class of submarines have what is called the Air Independent Propulsion (AIP) which enables non-nuclear submarines to operate for a long time without access to surface oxygen.
  • It also needs to be noted that the Defence Research and Development Organisation (DRDO) has an ongoing programme to build a fuel cell-based AIP system for Indian Naval Submarines.

About Nuclear Submarine (SSN)

  • SSNs have an infinite capacity to stay underwater. As they are not propelled by batteries, they need not emerge for charging by a diesel engine. Propelled by a nuclear-powered engine, these submarines only need to come to the surface for replenishing supplies for the crew.
  • SSNs are also able to move faster underwater than conventional submarines. All this allows a navy to deploy them at farther distances, and quicker. They are like the fighter jets of the underwater world.
  • India is taking two SSNs on lease from Russia, but the first of them is expected to be delivered only by 2025.
  • But, during this time India has developed its own SSBNs, INS Arihant and INS Arighat.
  • The SSBNs are strategic programmes and fall under the Strategic Forces Command, the tri-services command responsible for India’s nuclear weapon and act as a deterrent.

India’s Modernisation Plan:

  • 30 - Year Plan: The 30-year plan (2000-30) for the indigenous submarine construction, approved by the Cabinet Committee on Security in 1999, envisaged two production lines of six submarines each, built in India in partnership with a foreign Original Equipment Manufacturer (OEM). The projects were called P-75 and P-75I.
  • P-75: Of the six being built, P-75 has delivered three Kalvari Class Scorpene Submarines so far.
  • P-75I: It is yet to take off, the Request for Proposal was issued in July 2021. It will be India’s first under the Strategic Partnership Model, which came up in 2015.
  • India is building at least two larger SSBNs that will have bigger missiles, called S4 and S4* projects. The four SSBNs are expected to be commissioned before 2030.

Capabilities at a Glance

The total Submarines in the Fleet is 15. It includes:

  • Ballistic Missile Submarine (SSBNs)
  • Nuclear-Powered attack submarines (SSNs)
  • Diesel-electric attack submarines (SSKs)
  • Air-independent propulsion (AIP) enable.

In service

Under construction




Source: The Indian Express

Pradhan Mantri Suryodaya Yojana

Recently, Prime Minister announced Pradhan Mantri Suryodaya Yojana under which 1 crore households will get rooftop solar power systems. India’s Status of Current Solar Capacity India currently stands at 4th place globally in solar power capacity. As per Ministry of New an

Foreign Contribution Regulation Act (FCRA)- NGO 

The Foreign Contribution Regulation Act, 2010 (FCRA) registration of two prominent non-governmental organisations (NGOs) — Centre for Policy Research (CPR) and World Vision India (WVI) have been cancelled this month. What is FCRA? Key provisions of FCRA, 2010 Key aspects Description

Voice clone-AI

Voice clone fraud has been on the rise in India. AI voice cloning – It is the process of creating a synthetic replica of a person’s voice through machine learning and speech synthesis technology.It is called as voice deepfakesor audio deepfakes. Objective – To achieve a high level of na

Science communication- how to promote

Steps taken by India to promote Science Communication Publications and Information Directorate (PID) - An organisation under Council of Science and Industrial Research (CSIR) established in 1951 for publishing and disseminating scientific information in India. National science magazines- The PI

Universal Basic Income (UBI)- Analysis

Universal Basic Income (UBI) can strengthen welfare architecture and unlock the nation’s latent demographic potential. UBI - It is an income support mechanism typically intended to reach all or a very large portion of the population regardless of their earnings or employment status. Objective- To provide enough to co


Search By Date

Newsletter Subscription
SMS Alerts

Important Links

UPSC GS Mains Crash Course - RAW Prelims Answer Key 2024