This is a good article. Click here for more information.

KRI Nanggala (402)

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

refer to caption
KRI Nanggala underway in the Java Sea, August 2015
History
Indonesia
NameKRI Nanggala
NamesakeDivine spear of Prabhu Baladewa
Ordered2 April 1977
BuilderHowaldtswerke-Deutsche Werft
Laid down14 March 1978
Launched10 September 1980
Completed6 July 1981
Commissioned21 October 1981
Out of service21 April 2021
IdentificationPennant number 402
FateSank during torpedo drill, 21 April 2021
BadgeKRI Nanggala badge.svg
General characteristics
Class and type Cakra-class attack submarine
Displacement
  • 1,285 tons surfaced
  • 1,390 tons submerged
Length59.5 m (195 ft 3 in)
Beam6.2 m (20 ft 4 in)
Draft5.4 m (17 ft 9 in)
Propulsion
  • 4 × MTU 12V493 AZ80 GA31L diesel engines rated at 1.8 MW (2,400 hp)[1]
  • 4 × Siemens alternators rated at 2,300 hp (1.7 MW)
  • 1 × Siemens motor rated at 3.4 MW (4,600 hp)
  • 1 × shaft
Speed
  • 11 knots (20 km/h; 13 mph) surfaced[1]
  • 25 knots (46 km/h; 29 mph) submerged
Range8,200 nmi (15,200 km; 9,400 mi) at 8 kn (15 km/h; 9.2 mph)
Endurance50 days[1]
Test depth240 m (790 ft)[1]
Complement50 including special forces unit[2]
Crew6 officers, 28 enlisted[3]
Sensors and
processing systems
Electronic warfare
& decoys
  • ESM : Thomson-CSF DR2000U[1]
  • CMS : Kongsberg MSI-90U Mk 2[4]
Armament
  • 8 × 533 mm (21 in) bow tubes[1]
  • 14 × AEG SUT torpedoes

KRI Nanggala (402), also known as Nanggala II, was one of two Cakra-class Type 209/1300 diesel-electric attack submarines of the Indonesian Navy.

Ordered in 1977, Nanggala was launched in 1980 and commissioned in 1981. It conducted intelligence gathering operations in the Indian Ocean and around East Timor and North Kalimantan. It was a participant of the international Cooperation Afloat Readiness and Training naval exercise and conducted a passing exercise with USS Oklahoma City. The vessel underwent major refits by Daewoo Shipbuilding & Marine Engineering (DSME) in 2012 and Indonesian state-owned shipyard PT PAL in 2020.

On 21 April 2021, the ship went missing during a routine exercise in the Bali Sea. During the exercise, the ship was commanded by Colonel Harry Setyawan, with 49 crewmembers and 3 weapon specialists on board. The Indonesian Navy, assisted by other countries, began to search for the missing ship. On 24 April 2021, three days after the ship lost contact, debris from the ship was discovered 19 kilometres (12 mi) from the point of last contact, and the ship was declared sunk. There were no survivors; all 53 people on board the ship perished. On 26 April, the Indonesian government awarded posthumous promotions to everyone aboard the ship.

The cause of the sinking is presumed to be a power outage. The ship had experienced power outages before but recovered successfully. Lt. Col. Heri Oktavian, who was also killed in the incident, had previously voiced his frustrations about the maintenance status of the ship. Oktavian claimed that the workmanship quality and maintenance services performed by state-owned naval dockyard PT PAL are unsatisfactory.

Name[edit]

The submarine was named after the Nanggala, a powerful, divine short spear wielded by Prabhu Baladewa, a Hindu god mentioned in the Mahabharata and a character in wayang puppet theatre.[5][6] Legend states that the spear is capable of melting mountains and splitting oceans.[7]

The vessel was also known as Nanggala II in order to differentiate it from RI Nanggala (S-02), an older Whiskey-class submarine sharing the same name.[8]

Design and construction[edit]

Some of the first crews of KRI Nanggala, the date of the picture is unclear.
Members of Nanggala's first crew
An undated picture of KRI Nanggala, taken before the 2012 refitting
KRI Nanggala before 2012 refitting
Nanggala in training in East Kalimantan, with Indonesian soldiers on her deck.
Training near East Kalimantan, 1992
refer to caption
Periscope (above) and control room, in 2017 after South Korean refitting

KRI Nanggala was ordered on 2 April 1977[9] and was financed as part of a US$625 million loan by the West German government to the Indonesian government.[10] About $100 million was spent on the submarine and its sister vessel, KRI Cakra.[10] The vessel was designed by Ingenieurkontor Lübeck of Lübeck, constructed by Howaldtswerke-Deutsche Werft of Kiel, and sold by Ferrostaal of Essen – all acting together as a West German consortium.[1]

Nanggala was laid down on 14 March 1978 and launched on 10 September 1980.[1] It was tested in West German waters before it was handed over to Indonesia on 6 July 1981.[8]

Nanggala left West Germany in early August 1981 with 38 crew members under the command of Lieutenant Colonel Armand Aksyah.[8] The submarine was first presented to the public on the 36th anniversary of the Indonesian National Armed Forces on 5 October 1981.[11] Sixteen days later, it was commissioned by the Minister of Defense and Security, General M. Jusuf.[12]

Historical context[edit]

During the 1960s, Indonesia was known as one of the largest Asian naval powers, with 12 Soviet-made Whiskey-class submarines in its fleet.[13][14] However, by 1981, during the Indonesian New Order, when Cakra and Nanggala arrived in Indonesia to reinforce the country's naval defenses, only one of the 12 Whiskey-class submarines had still retained the ability to dive.[15][13] The Indonesian government had planned to purchase a Type 206A submarine from Germany in the late 1990s, but was unable to do so due to funding issues.[14]

During the beginning of the Reform Era, an embargo on military equipment imposed by the U.S., as well as continuing financial problems experienced as a result of the Asian financial crisis, meant that the Indonesian Navy was unable to procure any additional submarines until 2017.[14][13] As a result, Cakra and Nanggala were the only active submarines in the Indonesian Navy between the decommissioning of KRI Pasopati in 1994[16] and the commissioning of KRI Nagapasa in 2017.[17][18]

By 2020, Indonesia had made plans to own and operate eight submarines by 2024.[14]

Service history[edit]

Nanggala participated in several naval exercises, including the Cooperation Afloat Readiness and Training exercises in 2002 and 2015.[19][20] In 2004, the boat participated in the Joint Marine Operations Exercise held in the Indian Ocean, during which it sank the decommissioned KRI Rakata.[19][21] In August 2012, the boat conducted a passing exercise with USS Oklahoma City, accompanied by KRI Diponegoro and a Bölkow-Blohm helicopter.[22]

The submarine conducted a number of intelligence-gathering operations in the waters around Indonesia, including one in the Indian Ocean from April to May 1992, and another around East Timor from August to October 1999, in which the boat tracked the movements of the International Force East Timor as it landed in the region.[23] During May 2005, the submarine was tasked with scouting, infiltrating, and hunting down strategic targets around Ambalat, after Indonesian KRI Tedong Naga [id] and Malaysian KD Rencong were involved in a minor collision near the area.[24][23]

Nanggala underwent a refit at Howaldtswerke that was completed in 1989.[25] Roughly two decades later, the boat underwent a full refit for two years in South Korea by Daewoo Shipbuilding & Marine Engineering (DSME) that was completed in January 2012.[26][2][a] The refit cost US$63.7 million,[28] replaced much of the submarine's upper structure, and upgraded its weaponry, sonar, radar, combat control and propulsion systems.[29][2] After the refit, Nanggala became capable of firing four torpedoes simultaneously at four different targets and launching anti-ship missiles such as Exocet or Harpoon. Its safe diving depth was increased to 257 metres (843 ft), and its top speed was increased from 21.5 knots (39.8 km/h) to 25 knots (46 km/h).[2] In November 2016, the submarine was equipped with an ASELSAN KULAÇ echosounder system.[30]

In 2012, three crew members of the Nanggala died in a failed torpedo launch exercise. The submarine was then sent to South Korea for repair.[31]

Sinking[edit]

On 21 April 2021, Air chief marshal Hadi Tjahjanto, Commander of the Indonesian National Armed Forces, reported that Nanggala was believed to have disappeared in waters about 95 km (51 nautical miles) north of Bali.[15][b] Indonesian Navy spokesperson First Admiral Julius Widjojono [id] stated that Nanggala had been conducting a torpedo drill, but failed to report its results as expected.[32][33] Further details emerged that Nanggala had requested permission to dive to fire an SUT torpedo[21] at 03:00 WIB (20:00 UTC, 20 April).[34][35] At around 04:00, Nanggala should have been flooding its torpedo tubes in preparation for the firing of the torpedo. The last communication with Nanggala was at 04:25, when the commanding officer of the training task force would have authorized the firing of torpedo number 8.[36] Chief of Staff of the Indonesian Navy Yudo Margono reported that Nanggala had fired a live torpedo and a practice torpedo before contact was lost.[35][34][37]

The navy subsequently sent a distress call to the International Submarine Escape and Rescue Liaison Office at around 09:37 to report the boat as missing and presumably sunk.[38] The navy stated that it was possible that Nanggala experienced a power outage before falling to a depth of 600–700 m (2,000–2,300 ft).[37] Widjojono stated that Nanggala was able to dive to a depth of 500 m (1,600 ft).[35] The deepest areas of the Bali Sea are over 1,500 m (4,900 ft) below sea level.[39] It was also reported that the underwater telephone (UWT) of the submarine was defective during the drill, hampering communications between the boat and rescue vessels in the area.[40]

At the time it went missing, Nanggala had 53 people on board, including 49 crew members, 1 commander, and 3 weapons specialists.[41] The highest-ranking naval officer in the submarine was Colonel Harry Setyawan, the commander of the submarine unit of the 2nd Fleet Command. Subordinates with him were Lieutenant Colonel Heri Oktavian, the commander of the submarine, and Lieutenant Colonel Irfan Suri, an officer from the Weapons Materials and Electronics Service.[42]

At noon on 22 April, Yudo Margono stated that the oxygen reserves on Nanggala would be sufficient for the entire crew and passengers for three days after it had submerged, noting that the oxygen would run out on Saturday, 24 April, at 03:00 (20:00 UTC, 23 April).[43] Submarine experts stated that submarines have backup systems that may provide sufficient oxygen for some time depending on the state of the equipment.[44] A crisis center equipped with an ambulance and a mobile hyperbaric chamber was established at the 2nd Fleet Command [id] headquarters in Surabaya.[45][46] The center was also a source of information for the media and families of the submarine crew members.[46]

Indonesian president Joko Widodo stated that the safety of the crew of Nanggala was of top priority and invited everyone to pray for the crew's safety.[47]

Rescue efforts[edit]

On 21 April around 07:00, an aerial search revealed traces of an oil spill on the surface of the water near the location where the submarine was believed to have dived.[48][35] Indonesian Navy deployed three warships—KRI Diponegoro, KRI Raden Eddy Martadinata, and KRI I Gusti Ngurah Rai—to search for Nanggala.[49] Widjojono stated that a team of divers was searching for the boat.[32] Janes Defence News also reported that the navy had sent a number of other warships to the area.[38] The governments of Australia, Singapore, and India had responded to Indonesian requests for assistance.[48]

On 22 April, the Indonesian Navy reported that an oil slick had been observed at multiple locations.[50] Indonesian frigate Raden Eddy Martadinata had detected movement underwater at a speed of 2.5 knots (4.6 km/h) but was unable to obtain enough information to identify the contact before it disappeared.[50] Admiral Yudo Margono, Chief Staff of Indonesian Navy, also reported that an Indonesian naval vessel had detected an object that was magnetic at a depth of 50 to 100 metres (160 to 330 feet).[35][c]

The Indonesian Navy had deployed six additional ships to the area: KRI Dr. Soeharso, KRI Hasan Basri, KRI Karel Satsuitubun, KRI Singa, KRI Hiu and KRI Layang.[51] Yudo Margono also noted on Thursday that three submarines, five airplanes, and 21 warships had been deployed in the search effort.[35] Submarine KRI Alugoro had also joined the search.[52] KRI Rigel [id], a warship with more powerful sonar equipment, was expected to arrive on 23 April.[53][54] The Republic of Singapore Navy deployed its submarine rescue vessels, MV Swift Rescue and Royal Malaysian Navy sent its MV Mega Bakti respectively, to the scene.[50] Indian Navy announced that their deep-submergence rescue vehicle (DSRV) had departed naval facilities at Visakhapatnam, Andhra Pradesh, en route to the search area.[55] U.S. Department of Defense press secretary John Kirby stated that the department was sending airborne assets to assist in the search.[39] These included a P-8 Poseidon maritime patrol aircraft.[56][57]

On 23 April, the Indonesian National Police also sent four police ships equipped with remotely operated vehicles (ROVs) and sonar devices.[58] Fleet Commander Australia, Rear Admiral Mark Hammond announced that HMAS Ballarat and HMAS Sirius would join the search operation.[59] Other nations, including Germany, France, Russia, Turkey, and Thailand, offered assistance.[60]

Lieutenant Colonel Heri Oktavian
Colonel Harry Setyawan
Lt. Col Heri Oktavian (left) and Colonel Harry Setyawan, commanders aboard Nanggala when it sank in 2021

Discovery[edit]

The location where Nanggala was found

On 24 April 2021, the Indonesian Navy announced the finding of debris, including a part associated with torpedo tubes, a coolant pipe insulator, a bottle of periscope grease, and prayer rugs.[61][62][63] Because the debris was found within 10 nmi (19 km; 12 mi) of the point of last contact and no other vessels were believed to be in the area, the debris was believed to have come from the submarine, and Nanggala was declared sunk.[63][d] Yudo Margono stated that a sonar scan had shown the submarine at a depth of 850 m (2,800 ft),[64] and its crush depth was presumed to be 500 m (1,600 ft).[63] Due to the maximum operational depth limitation of 800 m of Rigel's two underwater ROVs, Rigel was unable to launch them and was assisted by the submarine rescue ship MV Swift Rescue of the Republic of Singapore Navy, which launched its 1,000m depth-capable drone and located and made visual contact with Nanggala at 09:04.[65][66]

On 25 April 2021, the Indonesian Navy confirmed that all 53 hands on board were lost.[67][68] Underwater scans identified parts of the submarine, including the rudder, diving plane, anchor, and external parts of the pressure hull, as well as items such as an MK11 submarine escape suit.[69]

The ROV Super Spartan from MV Swift Rescue of the Singapore Navy first made visual contact with the wreck and determined that the submarine had split into three parts.[70] Using a multibeam echosounder, KRI Rigel confirmed the final position of Nanggala at a depth of 838 m (2,749 ft) at the coordinates 7°48′56″S 114°51′20″E / 7.81556°S 114.85556°E / -7.81556; 114.85556Coordinates: 7°48′56″S 114°51′20″E / 7.81556°S 114.85556°E / -7.81556; 114.85556, roughly 1,400 m (1,500 yd) from where Nanggala had dived.[71][72][73]

Analysis[edit]

Cause[edit]

The Navy said Nanggala might have experienced a power outage.[37] The boat had experienced a power outage before because of a blown electrical fuse, but the boat successfully recovered after the ship executed an emergency main ballast tank blow.[74] After the finding of debris from Nanggala, Yudo Margono said the submarine might have cracked instead of exploded, as an explosion would have been detected by sonar.[75]

Indonesian legislator and retired Major General Tubagus Hasanuddin suspected the refit, performed by the South Korean firm DSME in 2012, may not have been performed properly. He said that after the refit, the submarine had failed a torpedo firing test, which resulted in three deaths. Hasanuddin also said Nanggala had exceeded its design capacity of 38 with 53 people on board when it sank. Yudo Margono said the vessel was combat ready, had received a letter of acceptance, and had a history of successful firing exercises.[76] Hasanuddin also questioned why 53 people were allowed on board the Nanggala when it sunk despite the ship only being designed for 34 crew.[77]

Poor maintenance[edit]

Nanggala commander Lt. Col. Heri Oktavian, who died in the incident, had voiced his frustration with the maintenance status of the Nanggala to Edna C. Pattisna, a close friend, who is also a reporter with local news media Kompas, for which she published an article titled Message from KRI Nanggala-402 Commander.[78] Oktavian claimed that the workmanship quality and maintenance services performed by state-owned shipyard PT PAL Indonesia were unsatisfactory and suffered from frequent delays. He lamented that an officer encountered criticism from his superiors for reporting the poor workmanship by PT PAL on the KRI Alugoro, a Changbogo-class submarine assembled by PT PAL's Surabaya yard and launched on 11 April 2019.[79] Oktavian was also quoted as saying: "This submarine (the Alugoro) by PT PAL, there's nothing good about it".[80] Nanggala was last serviced by PT PAL in 2020.[81] No further refitting of Nanggala was requested to DSME after the 2012 refit despite the need for submarines to undergo maintenance at least once every six years.[82][83]

Aftermath[edit]

refer to caption
Rahmat Eko Rahardjo was removed from his post.

After the Indonesian Navy declared Nanggala lost with all hands, the People's Consultative Assembly recommended a posthumous promotion for all personnel on board.[84] Hadi Tjahjanto stated that he would propose the promotions to Indonesian President Joko Widodo.[85] A day later, on 26 April, Joko Widodo announced that the government would award a posthumous promotion and confer posthumously the Bintang Jalasena (Navy Meritorious Service Star) to everyone on board Nanggala.[86] The ceremony conferring the awards and promotions was held on 29 April, attended by Joko Widodo,[87] Minister of Defense Prabowo Subianto, Hadi Tjahjanto, and Yudo Margono.[88][e]

Tubagus Hasanuddin recommended that the Indonesian Navy's remaining Cakra-class submarine be taken out of service.[76] Parliamentarian Utut Adianto stated that Indonesia's defences required modernization.[89] Frans Wuwung, former head of the engine room of Nanggala, stated that despite the submarine's age, its equipment was still in good condition due to proper maintenance and did not consider such a modernization necessary.[90]

Two days after the sub had been declared sunk, Rahmat Eko Rahardjo, the commander of the 2nd Fleet Naval Combat Squad who had given permission for Nanggala to dive,[91] and ING Sudihartawan, the commander of the 2nd Fleet, were relieved of their commands by Hadi Tjahjanto. Hadi appointed Iwan Isnurwanto, a former Nanggala crew member and chief of staff,[92] to replace the latter.[93] Iwan later appointed Wirawan Ady Prasetya — another Nanggala commander — to replace the position that Harry had left posthumously.[94]

Reactions[edit]

Condolences were expressed by the King of Malaysia,[95] Australian Prime Minister Scott Morrison,[96] the Korean Ministry of Defense,[97] Singapore Defence Minister Ng Eng Hen and Senior Minister Teo Chee Hean,[98] the UK's Minister of State for Asia, Nigel Adams, and ambassador to Indonesia, Owen Jenkins.[99] United States Secretary of Defense Lloyd Austin expressed his "heartfelt concern" in a call with Prabowo Subianto.[100]

During the search, use of the hashtag #PrayForKRINanggala402 and #KRINanggala402 became popular on Twitter.[101][102] After Nanggala had been declared sunk, the phrases "On Eternal Patrol" and "Rest In Peace", and the motto Wira Ananta Rudira (Sanskrit: Steadfast to the End), used by the submarine unit to which Nanggala belonged, saw increased usage.[103][104][105]

Salvage[edit]

On 3 May, two Chinese Navy ships, ocean tug Nantuo (195) and ocean salvage and rescue ship Yongxingdao (863), arrived to assist with the recovery of the wreck.[106] Scientific research vessel Explorer 2 was scheduled to arrive the next day.[106][107][f] There have also been discussions between the Indonesian Navy and state-owned oil regulator SKK Migas to raise the submarine.[106]

By 18 May, the team had successfully recovered two liferafts that weighed approximately 700 kg (1,500 lb) each.[107] However, they had yet to locate the submarine's pressure hull, and gave up on lifting the bridge after a sling was broken during a failed attempt, as the bridge likely weighed over 20 tonnes (20,000 kg; 44,000 lb).[107][108]

Notable former crew members[edit]

  • Rear Admiral Frans Wuwung, former head of engine room,[109] member of the People's Representative Council (2001–2002)[110]

See also[edit]

Notes[edit]

  1. ^ Nanggala did not return to operations until February 2012.[27]
  2. ^ The area is around 300 km (160 nautical miles) to the east of the large East Java city of Surabaya.
  3. ^ It is unclear if Achmad Riad and Yudo Margono were referring to the same object.
  4. ^ In addition, Korean writing was found on some of the debris, and Nanggala had been refitted in South Korea in 2012.[62]
  5. ^ All awardees received the Bintang Jalasena Nararya 'Navy Meritorious Service Star, Third Class'.[88]
  6. ^ Explorer 2 is also known by its Chinese name Tan Suo Er Hao.[106][107]

References[edit]

  1. ^ a b c d e f g h i Saunders, Stephen, ed. (2009). Jane's Fighting Ships 2009–2010. Jane's Information Group. p. 339. ISBN 9780710628886. Archived from the original on 30 April 2021. Retrieved 25 April 2021.
  2. ^ a b c d Boediwardhana, Wahyoe (2 June 2012). "RI submarines on par with neighbors after overhaul". Jakarta Post. Archived from the original on 11 May 2012. Retrieved 21 April 2021.
  3. ^ Ridzwan Rahmat (21 April 2021). "Indonesian Navy submarine missing in Bali Sea". Janes. Archived from the original on 21 April 2021. Retrieved 21 April 2021.
  4. ^ MSI-90U Mk 2 Combat Management System (PDF). Norway: Kongsberg. p. 6. Archived (PDF) from the original on 1 May 2017. Retrieved 23 April 2021.
  5. ^ Wisesa, Yosafat Diva Bayu (22 April 2021). "Ternyata KRI Nanggala-402 mengandung petir dari kekuatan ilahi Baladewa dan bisa belah gunung". Hops (in Indonesian). Archived from the original on 22 April 2021. Retrieved 22 April 2021.
  6. ^ "Shadow puppet, Prabu Baladewa". www.roots.gov.sg. Archived from the original on 22 April 2021. Retrieved 22 April 2021.
  7. ^ Handley, Erin; Renaldi, Erwin (26 April 2021). "What we know about the sunken Indonesian submarine KRI Nanggala". ABC News. Australian Broadcasting Corporation. Archived from the original on 26 April 2021. Retrieved 27 April 2021.
  8. ^ a b c ""Nanggala II" diserahkan". Kompas. 12 July 1981. p. 2. Archived from the original on 23 April 2021. Retrieved 21 April 2021. Excerpt of the newspaper could be seen in here Archived 30 April 2021 at the Wayback Machine.
  9. ^ Gardiner, Robert; Chumbley, Stephen, eds. (1995). Conway's All the World's Fighting Ships 1947–1995. Annapolis, Maryland, US: Naval Institute Press. p. 179. ISBN 1-55750-132-7.
  10. ^ a b "Dua kapal-selam baru untuk TNI-AL". Kompas (in Indonesian). 5 February 1977. Archived from the original on 23 April 2021. Retrieved 23 April 2021. Excerpt of the newspaper could be seen in here Archived 23 April 2021 at the Wayback Machineat 00.47. (Video )
  11. ^ "Jadilah ABRI yang Demikian". Tempo. 10 October 1981. Archived from the original on 21 April 2021. Retrieved 22 April 2021.
  12. ^ "Diresmikan Menhankam/Pangab: Tiga kapal perang baru dalam jajaran armada TNI-AL". Kompas. 22 October 1981. p. 1. Archived from the original on 22 April 2021. Retrieved 21 April 2021.
  13. ^ a b c "Tenggelamnya KRI Nanggala-402, "Tabah sampai Akhir"". kompas.id. 22 April 2021. Archived from the original on 25 April 2021.
  14. ^ a b c d "Tradisi TNI Angkatan Laut" (PDF) (in Indonesian). Dinas Perawatan Personel TNI AL. 2020. Archived (PDF) from the original on 7 July 2020. Retrieved 16 October 2021.
  15. ^ a b Pattisina, Edna C; Puttranto, Angger (21 April 2021). "Kapal Selam KRI Nanggala-402 Hilang di Utara Bali". kompas.id. Archived from the original on 21 April 2021. Retrieved 21 April 2021.
  16. ^ Pandia, Agnes Swetta (30 June 1998). "KRI Pasopati, Monumen Keperkasaan di Laut". Kompas. p. 9. Archived from the original on 22 April 2021. Retrieved 22 April 2021.
  17. ^ Erdianto, Kristian (28 August 2017). "Ini Kehebatan Kapal Selam Baru KRI Nagapasa 403 Milik TNI AL". Kompas (in Indonesian). Archived from the original on 15 November 2019. Retrieved 22 April 2021.
  18. ^ "Ramping Tapi Kekar". Tempo. 12 October 1991. Archived from the original on 21 April 2021. Retrieved 22 April 2021.
  19. ^ a b Tanjung, Agib (10 December 2014). "Mengenal KRI Nanggala 402, kapal selam tangguh andalan TNI AL". merdeka.com. Archived from the original on 2 January 2015. Retrieved 22 April 2021.
  20. ^ "KRI NANGGALA, JAVA SEA". DVIDS. 8 August 2015. Archived from the original on 23 April 2021. Retrieved 22 April 2021.
  21. ^ a b "KRI Nanggala-402, Submarine Purchased 1982 From Germany, Most Senior In Indonesian Navy". VOI – Waktunya Merevolusi Pemberitaan. Archived from the original on 22 April 2021. Retrieved 22 April 2021.
  22. ^ Marboen, Ade, ed. (30 August 2012). "KRI Nanggala-402 dan USS Oklahoma City latihan bersama di Laut Jawa". Antara. Archived from the original on 25 October 2012. Retrieved 25 October 2012.
  23. ^ a b Till, Geoffrey; Lean, Collin Koh Swee (2018). Naval Modernisation in Southeast Asia: Submarine Issues for Small and Medium Navies (PDF). 2. Palgrave Macmillan. pp. 64, 138. ISBN 978-3-319-86396-2. Archived (PDF) from the original on 23 April 2021. Retrieved 23 April 2021.
  24. ^ Pattisina, Edna C. (21 April 2021). "KRI Nanggala-402 Dulu Jadi Ujung Tombak Sengketa Blok Ambalat". kompas.id. Archived from the original on 21 April 2021. Retrieved 23 April 2021.
  25. ^ Warship International: Volume 27. International Naval Research Organization. 1990. p. 41. Archived from the original on 22 April 2021. Retrieved 21 April 2021.
  26. ^ 대우조선해양 (20 January 2012). "대우조선해양, 인도네시아 잠수함 성능개량사업 완료". 대우조선해양, 인도네시아 잠수함 성능개량사업 완료 – 뉴스와이어 (in Korean). Archived from the original on 22 May 2016. Retrieved 22 April 2021.
  27. ^ Pattiasina, Edna C. (6 February 2012). "Kapal Selam KRI Nanggala Kembali Beroperasi". KOMPAS.com (in Indonesian). Archived from the original on 21 April 2021. Retrieved 21 April 2021.
  28. ^ Laporan Perkembangan Pinjaman dan Hibah Triwulan IV Tahun 2011 (PDF). Jakarta: Directorate of Evaluation, Accounting and Settlement, Ministry of Finance. 2011. pp. L-26. Archived (PDF) from the original on 23 April 2021. Retrieved 23 April 2021.
  29. ^ "Indonesia searches for missing submarine with 53 on board". Reuters. 21 April 2021. Archived from the original on 21 April 2021. Retrieved 21 April 2021.
  30. ^ "Indonesian Navy vessel uses ASELSAN's KULAÇ". Daily Sabah. 21 November 2016. Archived from the original on 17 January 2021. Retrieved 22 April 2021.
  31. ^ Indonesia, C. N. N. "DPR: 3 TNI Pernah Tewas di Insiden Kapal Selam Nanggala 2012". nasional (in Indonesian). Archived from the original on 10 June 2021. Retrieved 10 June 2021.
  32. ^ a b "Kapal Selam TNI AL Hilang Kontak saat Latihan di Selat Bali". CNN Indonesia (in Indonesian). 21 April 2021. Archived from the original on 21 April 2021. Retrieved 21 April 2021.
  33. ^ Beo Da Costa, Agustinus; Lamb, Kate (21 April 2021). Petty, Martin (ed.). "Indonesian navy checking on submarine after failure to report back from exercise". Reuters. Archived from the original on 21 April 2021. Retrieved 21 April 2021.
  34. ^ a b Komara, Indra. "KRI Nanggala-402 Diduga Hilang Kontak 1 Jam Usai Dapat Izin Menyelam". detiknews (in Indonesian). Archived from the original on 22 April 2021. Retrieved 22 April 2021.
  35. ^ a b c d e f Masrur, Jamaluddin (21 April 2021). "Indonesian Navy searches for missing submarine with 53 people on board". CNN. Archived from the original on 21 April 2021. Retrieved 22 April 2021.
  36. ^ Media, Kompas Cyber (22 April 2021). "Komunikasi dengan KRI Nanggala-402 Masih Lancar hingga Tahap Penggenangan Torpedo, lalu Hilang Ketika Akan Diberi Otoritas". KOMPAS.com (in Indonesian). Archived from the original on 22 April 2021. Retrieved 22 April 2021.
  37. ^ a b c Achmad Nasrudin Yahya, 'Sebelum Hilang, Kapal Selam KRI Nanggala-402 Diduga Sempat Alami Black Out' Archived 21 April 2021 at the Wayback Machine [Before Disappearing, Indonesian National Submarine Naggala-402 Believed to have had a Black Out], Kompas.com, 22 April 2021.
  38. ^ a b Rahmat, Ridzwan (21 April 2021). "Indonesian Navy submarine missing in Bali Sea". Janes. Archived from the original on 21 April 2021. Retrieved 21 April 2021.
  39. ^ a b Anshori, Yuddy Cahya Budiman, Sultan (23 April 2021). "Desperate hunt for missing Indonesian submarine as oxygen set to run out". Reuters. Archived from the original on 23 April 2021. Retrieved 23 April 2021.
  40. ^ "Communications malfunction hampers rescue of missing Indonesian submarine". Janes.com. Archived from the original on 24 April 2021. Retrieved 25 April 2021.
  41. ^ "Indonesian navy searching for missing submarine with 53 on board; oil spill found near dive position". CNA. 21 April 2021. Archived from the original on 22 April 2021. Retrieved 22 April 2021.
  42. ^ Pratama, Aprilandika (21 April 2021). "Daftar 53 Awak Kapal Selam KRI Nanggala yang Tenggelam di Bali". Kumparan (in Indonesian). Archived from the original on 21 April 2021. Retrieved 21 April 2021.
  43. ^ "Sailors on missing KRI Nanggala submarine have oxygen until Saturday". The Jakarta Post. 22 April 2021. Archived from the original on 22 April 2021. Retrieved 22 April 2021.
  44. ^ Beech, Hannah; Suhartono, Muktita (23 April 2021). "Oxygen, and Time, Are Running Out for Indonesian Submarine". The New York Times. ISSN 0362-4331. Archived from the original on 23 April 2021. Retrieved 23 April 2021.
  45. ^ Pranishita, Ayu Khania (22 April 2021). "Pencarian KRI Nanggala, TNI buka posko crisis center di Surabaya dan Banyuwangi". ANTARA News Jawa Timur. Archived from the original on 7 June 2021. Retrieved 24 April 2021.
  46. ^ a b Hukmana, Siti Yona (22 April 2021). "Crisis Center KRI Nanggala-402 Didirikan di Surabaya dan Banyuwangi". Medcom. Archived from the original on 25 April 2021. Retrieved 24 April 2021.
  47. ^ Sinambela, Maruli (22 April 2011). "Kerahkan Semua Kekuatan, Jokowi: Keselamatan 53 Awak KRI Nanggala 402 Prioritas Utama". Vibizmedia. Archived from the original on 22 April 2021. Retrieved 22 April 2021.
  48. ^ a b "Search for missing Indonesian submarine reveals oil spill". Reuters. 21 April 2021. Archived from the original on 21 April 2021. Retrieved 21 April 2021.
  49. ^ Yahya, Achmad Nasrudin (22 April 2021). "TNI AL Pastikan Stok Oksigen Aman Bagi 53 Personel Kapal Selam KRI Nanggala-402". Kompas (in Indonesian). Archived from the original on 22 April 2021. Retrieved 22 April 2021.
  50. ^ a b c Siregar, Kiki (22 April 2021). "Vessels from Singapore and Malaysia to assist in search for missing Indonesian submarine". Channel News Asia. Archived from the original on 22 April 2021. Retrieved 22 April 2021.
  51. ^ Fanani, Ardian. "6 KRI Ada di Banyuwangi Cari Kapal Selam Nanggala-402 yang Hilang". detiknews (in Indonesian). Archived from the original on 22 April 2021. Retrieved 22 April 2021.
  52. ^ Tisnadibrata, Ismira Lutfia (22 April 2021). "Indonesia in race against time to find missing submarine before air supply runs out". Arab News. Archived from the original on 23 April 2021. Retrieved 23 April 2021.
  53. ^ Jamaluddin, Masrur. "Indonesian navy detects object during search for missing submarine". CNN. Archived from the original on 23 April 2021. Retrieved 23 April 2021.
  54. ^ Groizeleau, Vincent (13 March 2015). "Rigel : Un bâtiment indonésien made in France". Mer et Marine (in French). Archived from the original on 11 November 2017. Retrieved 25 April 2021.
  55. ^ Peri, Dinakar (22 April 2021). "Indian Navy dispatches DSRV to assist Indonesian Navy's search for missing submarine". The Hindu. ISSN 0971-751X. Archived from the original on 22 April 2021. Retrieved 22 April 2021.
  56. ^ Suadnyana, Sui. "Bantuan LN Pencari KRI Nanggala-402: MV Swift-Pesawat Poseidon". detiknews (in Indonesian). Archived from the original on 23 April 2021. Retrieved 23 April 2021.
  57. ^ Aitken, Peter (24 April 2021). "Indonesia submarine declared sunk, no hope of survivors". Associated Press. Archived from the original on 24 April 2021. Retrieved 24 April 2021.
  58. ^ Media, Kompas Cyber (23 April 2021). "Polri Kerahkan 4 Kapal Bantu Cari KRI Nanggala-402". KOMPAS.com (in Indonesian). Archived from the original on 24 April 2021. Retrieved 24 April 2021.
  59. ^ Hodge, Amanda (23 April 2021). "Australian warships join submarine search; oxygen to run out in hours". www.theaustralian.com.au. Archived from the original on 23 April 2021. Retrieved 23 April 2021.
  60. ^ Renuki H., Rendy (22 April 2021). "10 Negara Siap Bantu Pencarian Kapal Selam KRI Nanggala 402". Medcom. Archived from the original on 23 April 2021. Retrieved 23 April 2021.
  61. ^ Suadnyana, Sui. "Kepingan Komponen KRI Nanggala-402 Ditemukan, Diduga Ada Keretakan". detiknews (in Indonesian). Archived from the original on 24 April 2021. Retrieved 24 April 2021.
  62. ^ a b Beech, Hannah; Suhartono, Muktita (24 April 2021). "Debris From Indonesian Submarine Is Found, Ending Hopes of Rescue". The New York Times. Archived from the original on 24 April 2021. Retrieved 24 April 2021.
  63. ^ a b c Barrett, Chris; Rompies, Karuni (24 April 2021). "Indonesian submarine declared sunk after debris found". The Sydney Morning Herald. Archived from the original on 24 April 2021.
  64. ^ "Indonesian Navy says missing KRI Nanggala 402 sank". The Jakarta Post. Archived from the original on 24 April 2021. Retrieved 24 April 2021.
  65. ^ "KASAL: KRI Nanggala-402 karam terbelah tiga". Bisnis Metro (in Indonesian). 25 April 2021. Archived from the original on 9 June 2021. Retrieved 9 June 2021.
  66. ^ "Mengenal MV Swift Rescue Milik Singapura dan KRI Rigel TNI yang Temukan KRI Nanggala-402". VOI - Waktunya Merevolusi Pemberitaan (in Indonesian). Archived from the original on 6 May 2021. Retrieved 9 June 2021.
  67. ^ Persada, Syailendra (25 April 2021). "Panglima TNI Pastikan 53 Kru KRI Nanggala Dipastikan Gugur". Tempo. Archived from the original on 25 April 2021. Retrieved 25 April 2021.
  68. ^ Suadnyana, Sui. "Panglima TNI: Seluruh Awak KRI Nanggala-402 Gugur". detiknews (in Indonesian). Archived from the original on 25 April 2021. Retrieved 25 April 2021.
  69. ^ detikcom, Tim. "Bukti-bukti Otentik yang Menyatakan Awak KRI Nanggala-402 Gugur". detiknews (in Indonesian). Archived from the original on 25 April 2021. Retrieved 25 April 2021.
  70. ^ "Sunken missing Indonesian submarine found cracked open, officials say 53 crew members dead". The Straits Times. 25 April 2021. Archived from the original on 27 April 2021. Retrieved 25 April 2021.
  71. ^ JawaPos.com (25 April 2021). "KRI Nanggala-402 Tenggelam dan Terbelah Jadi Tiga Bagian". JawaPos.com (in Indonesian). Archived from the original on 9 June 2021. Retrieved 9 June 2021.
  72. ^ Suadnyana, Sui. "Tenggelam, KRI Nanggala-402 Terbelah Jadi 3 Bagian". detiknews (in Indonesian). Archived from the original on 25 April 2021. Retrieved 25 April 2021.
  73. ^ Romadoni, Ahmad. "Panglima TNI: KRI Nanggala Ditemukan, Seluruh Awak Kapal Selam Telah Gugur". kumparan (in Indonesian). Archived from the original on 25 April 2021. Retrieved 25 April 2021.
  74. ^ "KRI Nanggala 402 Pernah Alami Black Out, Ceritanya Bikin Merinding - SINDOnews". SINDOnews.com (in Indonesian). Archived from the original on 9 June 2021. Retrieved 9 June 2021.
  75. ^ Suadnyana, Sui. "KSAL: KRI Nanggala-402 Alami Keretakan, Bukan Ledakan". detiknews (in Indonesian). Archived from the original on 24 April 2021. Retrieved 24 April 2021.
  76. ^ a b detikcom, Tim. "TB Hasanuddin Duga Retrofit KRI Nanggala-402 di Korsel Gagal". detiknews (in Indonesian). Archived from the original on 25 April 2021. Retrieved 25 April 2021.
  77. ^ Newdick, Thomas. "The Search Is On For A Missing Indonesian Navy Submarine". The Drive. Archived from the original on 10 June 2021. Retrieved 10 June 2021.
  78. ^ Pattisina, Edna C (25 April 2021). "Pesan dari Komandan KRI Nanggala-402". KOMPAS. Archived from the original on 17 July 2021. Retrieved 19 July 2021.
  79. ^ Zainuddin, Hasbi (26 April 2021). "Overhaul, Mesin KRI Nanggala-402 Harusnya Dibongkar-Turun Mesin Sejak 2020: Komandan Kapal Pernah Curhat". Makassar Terkini (in Indonesian). Archived from the original on 9 June 2021. Retrieved 9 June 2021.
  80. ^ "Sampai Berani Sebut 'Enggak Ada yang Benar-benar Bagus', Komandan KRI Nanggala-402 Heri Oktavian Keluhkan Kapal Selam Buatan PT PAL yang Dinilainya Hanya Bisa Lakukan Ini". intisari.grid.id (in Indonesian). Archived from the original on 9 June 2021. Retrieved 9 June 2021.
  81. ^ "Tragedi kapal selam KRI Nanggala: Kecelakaan ketiga libatkan kapal tua TNI, apa dampaknya bagi keamanan laut?". BBC News Indonesia (in Indonesian). Archived from the original on 10 June 2021. Retrieved 10 June 2021.
  82. ^ Jo Kwang-hyun (23 April 2021). "'실종 인도네시아 잠수함'...대우조선, 귀책사유 없다". Asia Times (in Korean). Archived from the original on 28 April 2021. Retrieved 28 April 2021.
  83. ^ "53명 태우고 사라진 인니 잠수함, 왜 무리한 훈련 나섰나". Hankook Ilbo (in Korean). 22 April 2021. Archived from the original on 28 April 2021. Retrieved 28 April 2021.
  84. ^ Muhammad, Rivan (25 April 2021). "Gugur Saat Bertugas, Seluruh Awak KRI Nanggala-402 Direkomendasikan Terima Kenaikan Pangkat Anumerta". Pikiran Rakyat Bekasi (in Indonesian). Archived from the original on 25 April 2021. Retrieved 25 April 2021.
  85. ^ Suadnyana, Sui. "Gugur, 53 Awak KRI Nanggala-402 Akan Diberi Kenaikan Pangkat". detiknews (in Indonesian). Archived from the original on 25 April 2021. Retrieved 25 April 2021.
  86. ^ Nugraheny, Dian Erika (26 April 2021). "Pemerintah Beri Penghargaan Naik Pangkat ke 53 Awak KRI Nanggala-402 yang Gugur". Kompas (in Indonesian). Archived from the original on 26 April 2021. Retrieved 26 April 2021.
  87. ^ Hafidha, Selma Intania (30 April 2021). "6 Momen Kenaikan Pangkat Luar Biasa Kepada Awak KRI Nanggala 402, Penuh Haru". Liputan 6 (in Indonesian). Archived from the original on 1 May 2021. Retrieved 1 May 2021.
  88. ^ a b Yahya, Achmad Nasrudin (29 April 2021). "Prajurit KRI Nanggala yang Gugur Dapat Anugerah Tanda Kehormatan dan Kenaikan Pangkat Luar Biasa". Kompas (in Indonesian). Archived from the original on 16 May 2022. Retrieved 1 May 2021.
  89. ^ "Tenggelamnya KRI Nanggala Sinyal Darurat Peremajaan Alutsista". kompas.id. 22 April 2021. Archived from the original on 16 May 2022. Retrieved 26 April 2021.
  90. ^ Wibowo, Kukuh S. (24 April 2021). "Eks KKM KRI Nanggala Minta Hilangnya Kapal Tak Dikaitkan Peremajaan Alutsista". Tempo. Archived from the original on 26 April 2021. Retrieved 26 April 2021.
  91. ^ Media, Kompas Cyber (21 April 2021). "Kronologi Hilangnya Kapal Selam Nanggala-402 di Utara Bali Halaman all". KOMPAS.com (in Indonesian). Archived from the original on 16 May 2022. Retrieved 1 May 2021.
  92. ^ "Profil Iwan Isnurwanto, Eks Awak KRI Nanggala Kini Jabat Panglima Koarmada II". kumparan (in Indonesian). Archived from the original on 3 May 2021. Retrieved 3 May 2021.
  93. ^ Media, Kompas Cyber (28 April 2021). "Panglima TNI Mutasi Panglima Komando Armada II hingga Kapuspen Halaman all". KOMPAS.com (in Indonesian). Archived from the original on 1 May 2021. Retrieved 1 May 2021.
  94. ^ Arsilan, Rifki (25 May 2021). "Kolonel Wirawan Jadi Dansatsel Ganti Posisi Komandan KRI Nanggala 402". Viva. Archived from the original on 16 May 2022. Retrieved 22 August 2021.
  95. ^ Sunday, 25 Apr 2021 06:48 PM MYT. "Agong, Permaisuri express condolences to Indonesian president, people over submarine tragedy | Malay Mail". www.malaymail.com. Archived from the original on 25 April 2021. Retrieved 25 April 2021.
  96. ^ "PM sends Indonesia condolences over sub". Yahoo News. 26 April 2021. Archived from the original on 26 April 2021. Retrieved 26 April 2021.
  97. ^ Miranti T.V, Benedikta (22 April 2021). "Kemenhan Korea Selatan Ucapkan Belasungkawa Atas Hilangnya KRI Nanggala 402". liputan6.com (in Indonesian). Archived from the original on 25 April 2021. Retrieved 24 April 2021.
  98. ^ "All 53 on board sunken Indonesian submarine confirmed dead, more debris found: Military chief". CNA. Archived from the original on 25 April 2021. Retrieved 25 April 2021.
  99. ^ Miranti T.V, Benedikta (24 April 2021). "Menlu dan Dubes Inggris Ucapkan Bela Sungkawa atas Tragedi KRI Nanggala 402". liputan6.com (in Indonesian). Archived from the original on 25 April 2021. Retrieved 24 April 2021.
  100. ^ "Readout of Secretary of Defense Lloyd Austin III Phone Call With Indonesian Minister of Defense, Prabowo Subianto". U.S. DEPARTMENT OF DEFENSE. Archived from the original on 23 April 2021. Retrieved 24 April 2021.
  101. ^ Bramasta, Dandy Bayu (24 April 2021). Kurniawan, Rendika Ferri (ed.). "#PrayForKRINanggala402, Doa Warganet KRI Nanggala-402 Segera Ditemukan Halaman all". KOMPAS.com (in Indonesian). Archived from the original on 25 April 2021. Retrieved 24 April 2021.
  102. ^ Batubara, Puteranegara (22 April 2021). "Trending Topic di Twitter, Warganet Berdoa KRI Nanggala 402 Segera Ditemukan : Okezone Nasional". Okezone (in Indonesian). Archived from the original on 25 April 2021. Retrieved 25 April 2021.
  103. ^ Puteri, Bertilia. "'On Eternal Patrol' Trending Usai Kapal Selam KRI Nanggala-402 Dinyatakan Tenggelam". WowKeren.com. Archived from the original on 25 April 2021. Retrieved 24 April 2021.
  104. ^ "Tenggelamnya Kapal Selam KRI Nanggala dan Semboyan Wira Ananta Rudira". kumparan (in Indonesian). Archived from the original on 25 April 2021. Retrieved 25 April 2021.
  105. ^ "Berlomba Dengan Waktu, Rest In Peace KRI Nanggala 402 Trending di Twitter, Tim Optimalkan Pencarian". Bangka Pos (in Indonesian). Archived from the original on 25 April 2021. Retrieved 25 April 2021.
  106. ^ a b c d Mahadzir, Dzirhan (4 May 2021). "Chinese Navy to Help with Recovery of Indonesian Sub Wreck". USNI News. Archived from the original on 16 May 2021. Retrieved 6 May 2021.
  107. ^ a b c d Barrett, Chris; Rompies, Karuni (18 May 2021). "Lost submarine fragments found on bottom of ocean but no bodies". The Sydney Morning Herald. Archived from the original on 25 May 2021. Retrieved 16 October 2021.
  108. ^ Suadnyana, Sui (18 May 2021). "Liferaft KRI Nanggala Berhasil Diangkat, Anjungan Kapal Masih Tertahan". detikcom (in Indonesian). Archived from the original on 25 May 2021. Retrieved 16 October 2021.
  109. ^ Gunawan, Deden. "Kala Nanggala Cegah Australia Masuk Timtim Jelang Jajak Pendapat". detiknews (in Indonesian). Archived from the original on 25 April 2021. Retrieved 25 April 2021.
  110. ^ Kusuma, Dyah; Dewanto, Hario (28 April 2001). "TNI Membantah Pergantian Anggota Fraksi TNI/Polri Dadakan". liputan6.com (in Indonesian). Archived from the original on 16 May 2018. Retrieved 25 April 2021.