Military Wiki
Russian submarine K-152 Nerpa
INS Chakra SSN attribute Ajai Shukla
Project 971U serving the Indian Navy
Career (Russia) Naval Ensign of Russia
Name: K-152 Nerpa
Namesake: Baikal Seal
Builder: Amur Shipbuilding Plant, Komsomolsk-on-Amur
Laid down: 1993
Launched: October 2008
Commissioned: 2009
Fate: Transferred on lease to the Indian Navy, 4 April 2012
Career (India) Naval Ensign of India
Name: Chakra
Commissioned: 4 April 2012
Homeport: Vishakhapatnam
Status: in active service, as of 2024
General characteristics
Displacement: 8,140 tonnes (8,010 long tons) surfaced
Length: 108.0–111.7 m (354.3–366.5 ft) (sources vary)
Beam: 13.5 m (44 ft 3 in)
Draught: 9.6 m (31 ft 6 in)

The INS Chakra is a 8,140-tonne (8,010-long-ton) Project 971[1][2] (or Project 518[3]) Akula class submarine (NATO: Akula II[1][2]) type nuclear-powered attack submarine. Construction was started in 1993, but suspended due to lack of funding. The Indian Navy sponsored the building and sea trials of the submarine provided it was given to the Indian Navy on lease for 10 years. It was launched as the K-152 Nerpa in October 2008 and entered service with the Russian Navy in late 2009. The submarine was leased to the Indian Navy in 2011, after extensive trials and was formally commissioned into service as the INS Chakra II at a ceremony in Visakhapatnam on 4 April 2012.[4] The INS Chakra joins the Eastern Naval Command at Visakhapatnam.[5]

While K-152 Nerpa was undergoing sea trials in the Sea of Japan on 8 November 2008, an accident caused the deaths of some twenty sailors and injury to twenty-one others. A fire suppression system discharged gas in the bow of the sub, suffocating civilian specialists and navy crew members.


The Nerpa was laid down at the Komsomolsk-on-Amur shipyard in 1993, but its completion was delayed for nearly a decade due to a lack of funds caused by the economic crisis of the early 1990s.[6] The partly constructed vessel was mothballed until 2004, when Rosprom (the Federal Agency for Industry) signed an agreement with the Indian government to complete the submarine and lease it to the Indian Navy. The vessel was intended to be completed by 2007, but underwent further delays. In 2007, it was transferred to the Vostok shipyard in the closed city of Bolshoy Kamen, Primorsky Krai, for fitting-out. It was launched in October 2008 for sea trials, following which it was due to be handed over to the Russian Defence Ministry.[7] Reports in the Indian media suggest that the resumption of construction was underwritten with Indian funding.[8] The standards of the vessel's construction were criticised by several commentators. Alexander Golts, defence editor of the Yezhednevny Zhurnal newspaper, said that in the 1980s, the Amur shipyard turned out submarines "one after another, like pancakes,"[9] but from 1993 to 2008 had produced just one. "The old specialists had left, and the new ones lacked professionalism."[9] An unnamed worker at the Amur shipyard told Komsomolskaya Pravda that there were "questions about the quality of the metal that was used in building the nuclear submarine", some of which had been bought from China, and alleged that "when the first trials of the submarine were carried out water was leaking in between the seams! So it is not surprising that the work dragged on."[7]

During May 2009, the repairs were reported to be almost complete and new sea trials were planned for June 15–20.[10] However, by October 2009, the work had still not been completed due to the shipyard's electrical supply having been disconnected. Nikolai Povzyk, the head of the shipyard, complained they had not been paid the 1.9 billion roubles (63.8 million dollars) owed for the work carried out on the Nerpa.[11]

Lease to India[]

AkulaProjekt971U right

INS Chakra of the Indian Navy

INS Chakra

Chakra in the open sea, flying colours of the Indian Navy

As of 2015, Russia had an agreement pending with India worth US$2 billion for the lease of Nerpa and another Project 971 Shchuka-B class submarine.[12] Of this, K-152 Nerpa will be leased for 10 years to India at an estimated cost of US$670 million. The submarine was finally handed over to India on 30 Dec 2011.[13] After being handed over to the Indian Navy, it would be commissioned as INS Chakra.[14] Nerpa is the Russian word for the Baikal seal,[15][16] and Chakra is a wheel or a disc.

Indian naval crews earlier trained to operate the submarine near St. Petersburg and another group of sailors was expected to arrive in Vladivostok in late 2008 for joining sea trials.[17] The training of the crew was viewed as crucial to India's own nuclear submarine program, known as the Arihant class submarine.[18]

After the 2008 accident, there were conflicting reports over the status of the lease. A Russian defence industry official denied that talks had been held with India on the delivery of the nuclear submarine. "Russia did not launch talks on a contract to supply India with the Nerpa nuclear-powered submarine."[19] General of the Army Nikolai Marakov stated that Russia would commission the Nerpa and that it would join seven other Akula class submarines in Russia's Pacific Fleet. "The sum of $650-780 million, which Rosoboron export and the Amur Shipbuilding Plant had negotiated over a long period of time with the Indian Ministry of Defence, will now be found in Russia," he said.[20]

However, in May 2009, both Russian and Indian defence officials confirmed that the Nerpa would be joining the Indian Navy by the end of 2009, after Russian President Vladimir Putin visited the yard and announced an immediate release of 1.2 billion roubles, for the submarine construction.[21] On December 28, 2009, Nerpa was commissioned and joined the Russian Navy. The submarine underwent further adjustments in February 2010.[22] As of August 2010, Russia was training a crew from the Indian Navy to sail the ship to India in fulfilment of the lease agreement.[23] INS Chakra was expected to be commissioned into the Indian Navy before October 2011.[24]

On July 1, 2011, Russian Navy chief Admiral Vladimir Vysotsky has been quoted as holding that "the Indian crew is now absolutely prepared for operating the submarine", which will be on a 10-year lease.[25]

On January 23, 2012, home voyage under Indian control from the Russian port of Vladivostok to its Indian base Visakhapatnam, commenced.[26] Official Russian announcement of the transfer was still pending at that time. The ship was identified as "INS Chakra II" of the "Akula II" class.[citation needed] The similarly named Chakra was a Charlie I-class submarine leased by India from Russia 1988-1992.

INS Chakra was officially inducted into the Indian Navy on April 4, 2012.[27][28]

2008 accident[]

Russian submarine K-152 Nerpa
Date Saturday 8 November 2008
Location Pacific Ocean, Sea of Japan, off the coast of Vladivostok[29]
20 killed
21 injured
Accident occurred on board the Russian submarine K-152 Nerpa

An accident aboard K-152 Nerpa occurred at 8:30 PM local time on 8 November 2008,[30] during an underwater test run in the Pacific Ocean.[31] A total of 208 people - 81 military personnel and 127 civilians - were on board at the time of the accident.[6] At least 20 people were killed by asphyxiation[32] and at least 21 more were injured,[33] marking the worst Russian submarine disaster since the Kursk sank in 2000.[34][35] Three of the dead were military personnel and the rest were civilians from the Vostok, Zvezda, Era and Amur shipbuilding yards who were members of the acceptance team.[36]

The incident involved the accidental triggering of a fire extinguishing system which sealed two forward compartments and released freon R-114B2 (Dibromotetrafluoroethane)[37] gas into them.[6] According to survivors, those affected by the gas release were caught off guard and may not have been alerted in time due to warning sirens sounding only after the gas had already begun pouring in. Some of the victims were reported to have been unable to turn on breathing kits before they suffocated.[38]

On 10 November, a Russian Navy statement blamed the disaster on an "unsanctioned operation" of the fire suppression system aboard the Nerpa.[6] Preliminary investigations concluded that the system had triggered automatically without human intervention. On 13 November, naval investigators announced that a crewman had turned on the system "without permission or any particular grounds".[39][40]


The K-152 Nerpa finds a mention in the Hollywood film The Darkest Hour as the nuclear submarine hiding in the Moscow River to take survivors of alien attack to safety.


  1. 1.0 1.1 Russia Hands Over Nerpa Nuclear Sub to India
  2. 2.0 2.1 K-152 Nerpa: Russian Akula II class nuclear attack submarine
  3. Prime Minister Vladimir Putin has a working meeting with Roman Trotsenko, President of the United Shipbuilding Corporation (USC)
  4. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£ (4 April 2012). "Russian-built nuclear submarine joins Indian navy". Retrieved 4 April 2012. 
  5. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£ (April 16, 2012). "Indian Navy Inducts Nuclear-powered Attack Submarine". Defense Media Network. 
  6. 6.0 6.1 6.2 6.3 Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£ (9 November 2008). "Twenty Persons Perished Aboard a Submarine Due to a Defective Fire-Extinguishing System". Komsomolskaya Pravda. 
  7. 7.0 7.1 Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£ (9 November 2008). "In Its First Trials the Submarine Nerpa Leaked at the Seams". Komsomolskaya Pravda. 
  8. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£. "Shipping, Shipbuilding And Offshore News". Marine Log. Retrieved 2008-11-11. 
  9. 9.0 9.1 Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£. "Behind the Russian Sub Disaster.". Newsweek. Retrieved 2008-11-11. 
  10. New sea trials of Nerpa submarine set for June - paper RIA Novosti 2009-05-13
  11. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£ (October 8, 2009). "Repairs of India-bound Russian sub hit by lack of funds: report". Retrieved 2010-02-21. 
  12. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£ (2008-11-09). "More than 20 killed in Russian nuclear sub accident: spokesman". AFP. Archived from the original on 2009-02-23. Retrieved 2008-11-18. 
  13. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£ (2011-12-30). "Russia hands over Nerpa attack submarine to India". Retrieved 2012-07-19. 
  14. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£ (10 November 2008). "Nuclear Submarine Accident Kills 20". Moscow Times. Retrieved 2008-11-11. 
  15. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£. "Baikal Seal". Seal Conservation Society. Retrieved 2008-11-21. [dead link]
  16. John Cross, Robert Charman (2006). Healing with the Chakra Energy System. Berkeley, CA: North Atlantic Books. pp. 17–18. ISBN 1-55643-625-4. 
  17. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£ (10 November 2008). "No Significant Damage to Russian Sub". Times of India. Retrieved 2008-11-28. 
  18. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£. "Accident on Russian submarine meant for India kills 20.". The Economic Times. Retrieved 2008-11-11. 
  19. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£. "Russian defence official denies doomed sub meant for India.". RIA Novosti. Retrieved 2008-11-17. 
  20. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£ (18 November 2008). "Nerpa nuclear submarine to join Russian Navy - top brass". RIA Novosti. Retrieved 2008-11-20. 
  21. India to acquire Russian nuclear submarine on lease by year end
  22. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£. "Russia's Nerpa nuclear sub to be 'fine-tuned' next month". Retrieved 14 May 2011. 
  23. Russian atomic sub leased to India — RT
  24. K-152 Nerpa for the Indian Navy | Russia & India Report
  25. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£ (2011-07-02). "Russia to hand over India nuclear sub by year-end". The Times Of India. 
  26. AFP (Agence France-Presse) Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£ (2012-01-23). "India sails new nuclear submarine home". Retrieved 2012-01-23. 
  27. Economic Times news article: INS Chakra: Govt inducts Russian-origin Akula II class Nerpa into Navy
  28. India Today news article: INS Chakra formally inducted into Indian Navy
  29. Unnithan, Sandeep (Mumbai, November 9, 2008). "Freak accident on Russian N-submarine kills 21". India Today. Retrieved 2008-11-09. [dead link]
  30. Loiko, Sergei L. (8 November 2008). "False fire alarm blamed in Russian sub deaths". The Columbus Dispatch. Retrieved 2008-11-11. 
  31. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£ (2008-11-08). "Russia: More than 20 dead in nuclear sub accident". CNN. Retrieved 2008-11-08. [dead link]
  32. Gutterman, Steve (2008-11-09). "Russian navy: sub accident kills more than 20". Retrieved 2008-11-09. [dead link]
  33. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£ (02:16 GMT, Sunday, 9 November 2008). "Twenty die on Russian submarine". BBC. Retrieved 2008-11-09. 
  34. Syal, Rajeev (Sunday November 9, 2008 00.01 GMT). "Twenty die in nuclear submarine accident". London: Retrieved 2008-11-09. 
  35. Faulconbridge, Guy (Sat Nov 8, 2008 10:57pm EST). "At least 20 die in accident on Russian nuclear sub". Reuters. Retrieved 2008-11-09. 
  36. Ren TV, Moscow, 2030 GMT 10 November 2008
  37. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£ (November 11, 2008). "Fire on Board the Russian Navy Akula II Nuclear Submarine kills Twenty Russian Sailors". International Online Defence Magazine. 
  38. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£ (11 November 2008). "Russian sub survivors: Freon killed as crew slept". Retrieved 2008-11-18. [dead link]
  39. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£ (15 November 2008). "Матрос запустил смертельный газ на глазах у своего командира?". Komsomolskaya Pravda. Retrieved 2008-11-18.  (Russian)
  40. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£ (15 November 2008). "Матрос включил систему пожаротушения на "Нерпе" от скуки". Retrieved 2008-11-18.  (Russian)

All or a portion of this article consists of text from Wikipedia, and is therefore Creative Commons Licensed under GFDL.
The original article can be found at Russian submarine K-152 Nerpa and the edit history here.