ROKS Cheonan (PCC-772)

This article is about the Korean naval ship. For the article about the sinking of this ship, see ROKS Cheonan sinking.

South Korean and US Navy admirals inspecting the wreckage of the Cheonan at Pyeongtaek on 13 September 2010.
Career
Name:	Cheonan (천안)
Namesake:	Cheonan
Operator:	Republic of Korea Navy
Builder:	Hyundai Heavy Industries Co., Ltd. Ulsan, South Korea
Launched:	January 1989
Commissioned:	1989
Identification:	Pennant number PCC-772
Fate:	Sunk on 26 March 2010 at 37°55′45″N 124°36′02″E / 37.92917°N 124.60056°E / 37.92917; 124.60056Coordinates: 37°55′45″N 124°36′02″E / 37.92917°N 124.60056°E / 37.92917; 124.60056
Status:	Salvaged in April 2010
Notes:	[1][2][3]
General characteristics
Class and type:	Pohang-class corvette
Displacement:	1,200 tonnes
Length:	88 m (289 ft)
Draft:	2.9 m (9 ft 6 in)
Propulsion:	CODOG unit
Speed:	Maximum 32 knots (59 km/h) Cruising 15 knots (28 km/h)
Range:	4,000 nautical miles (7,400 km)
Crew:	104
Armament:	4 × Harpoon missiles 2 × OTO Melara(76mm)/62 compact cannon 2 × Breda 40mm/70 cannon 6 × Mark 46 torpedoes 12 × Mark 9 depth charges
Notes:	[4][5][6]

ROKS Cheonan (PCC-772) was a South Korean Pohang-class corvette of the Republic of Korea Navy (ROKN), commissioned in 1989. On 26 March 2010, it broke in two and sank near the sea border with North Korea. An investigation conducted by an international team of experts from South Korea, United States, United Kingdom, Australia, and Sweden concluded that Cheonan was sunk by a torpedo launched by a North Korean Yeono class miniature submarine.^{[2][3][7][8][9]} On 9 July 2010, the United Nations Security Council issued a Presidential Statement condemning the attack but without identifying the attacker.^[10]

History

Service history

Cheonan was launched in November 1989 from Hyundai Heavy Industries, Ulsan, South Korea.^[11] The ship's primary mission was coastal patrol, with an emphasis on anti-submarine operations.^[5] The Cheonan was one of the ships involved in the First Battle of Yeonpyeong in 1999.^[12] It is also known that the ship suffered slight damage on the stern in the First Battle of Yeonpyeong.^[13] The ship had been scheduled for decommissioning in 2019.^[11]

Sinking, recovery and aftermath

Sinking

Main article: ROKS Cheonan sinking

On 26 March 2010, an explosion occurred near the rear of the Cheonan, causing the ship to break in two.^[14] The cause of this explosion was not immediately determined.^[15][16]

The 1,200 tonne ship started sinking at 21:20 local time (12:20 UTC) about 1 nautical mile (1.9 km) off the south-west coast of Baengnyeong Island in the Yellow Sea.^{[17][4][18][19]} The island is located on the South Korean (ROK) side of the Northern Limit Line, the de facto boundary dividing South from North Korea (DPRK).^[4] The ship had a crew of 104 men at the time of sinking, and a total of 58 crew were rescued.^[4] Another 46 crew were unaccounted for. Cheonan's captain, Commander Choi Won-il, said that the ship broke into two and the stern sank within five minutes after the explosion and while he was still assessing the situation.^[20] On 17 April 2010, North Korea denied any involvement in the sinking of Cheonan.^[21]

Baengnyeong Island (red)

Sinseong, a sister ship of Cheonan

Rescue efforts

Initially six South Korean Navy and two South Korean Coastguard ships assisted in the rescue as well as aircraft from the Republic of Korea Air Force.^[22] It was reported on March 27 that hopes of finding the 46 missing crew alive were fading. Survival time in the water was estimated at about two hours and large waves were hampering rescue attempts.^[20][23] The ship sank in 45 meter deep waters with a small portion of the overturned hull still visible above water. It was expected that it would take up to 20 days to salvage the ship.^[24]

During the course of the search and rescue effort over 24 military vessels were involved,^[25] including at least three US Navy vessels, the USNS Salvor, the USS Harpers Ferry, and the USS Shiloh.^[26]

On 30 March 2010 it was reported that one South Korean naval diver had died after losing consciousness whilst searching for survivors and another had been hospitalised.^[27]

On 3 April 2010, South Korean officials said that a private fishing boat involved in the rescue operations had collided with a Cambodian freighter, sinking the fishing boat and killing at least two people, with seven reported missing.^[28] The same day, the Joint Chiefs of Staff of South Korea said that one body of the 46 missing sailors had been found.^[28][29]

Later on 3 April 2010 South Korea called off the rescue operation for the missing sailors, after families of the sailors asked for the operation to be suspended for fear of further casualties among the rescue divers. The military's focus then shifted towards salvage operations, which were predicted to take up to a month to complete.^[28]

Recovery

On 15 April 2010, the stern section of the ship was winched from the seabed by a large floating crane, drained of water and placed on a barge for transportation to the Pyongtaek navy base.^[30] The same crane raised the bow portion of the Cheonan on 24 April 2010.^[31] The salvaged parts of the ship were taken to Pyongtaek navy base for an investigation into the cause of the sinking by both South Korean and foreign experts.^[30]

Cause of sinking

Main article: ROKS Cheonan sinking#Investigation

On 25 April 2010, South Korea's defense minister, Kim Tae-Young, said that the most likely cause of the explosion that sank the Cheonan was a torpedo; his statements were the first time that a South Korean official publicly cited such a cause. Kim said that "A bubble jet caused by a heavy torpedo is thought to be the most likely thing to be blamed, but various other possibilities are also under review." A bubble jet is caused by an underwater explosion which changes the pressure of water, and whose force can cause a ship to break apart. The bubble jet theory was supported by one of the investigators into the incident, who had said that there was no evidence that an explosion had occurred in contact with a ship, and that a non-contact explosion had most likely broken the ship in half.^[32]

On 20 May 2010, an international commission investigating the sinking of Cheonan presented its findings, and said that the ship was sunk by a North Korean torpedo attack.^[8][33] The torpedo parts recovered at the site of the explosion by a dredging ship on May 15, which include 5x5 bladed contra-rotating propellers, propulsion motor and a steering section, were claimed to perfectly match the schematics of the CHT-02D torpedo included in introductory brochures provided to foreign countries by North Korea for export purposes, but the brochures were never made public. The markings in Hangul, which read "1번" (or No. 1 in English), found inside the end of the propulsion section were said to have been consistent with markings on a previously obtained North Korean torpedo.^[34] However, some have pointed out that in the North, "호"(pronounced "ho") is most often used rather than "번"; and that a North Korean torpedo found seven years ago bears the marking "4호".^[35] Russian and Chinese torpedoes are marked in their respective languages. The CHT-02D torpedo manufactured by North Korea utilizes acoustic/wake homing and passive acoustic tracking methods.^[34] However, an expert at a South Korean missile manufacturer disagreed with the idea that the submarine alleged by ROK authorities to have shot the torpedo actually has the capability: "Sango class submarines are known to be used by North Korean commandos in infiltrating areas or laying mines, but they apparently do not have an advanced system to guide homing weapons. If a smaller class submarine was involved, there is a bigger question mark."^[36]

One member of the investigative team, Shin Sang-cheol, who would be summoned on charges of spreading unsubstantiated rumors, publicly expressed doubts by saying "The magnified photo of the evidence showed that the marking was written on the rusted surface. If it were the North who marked it, the marking should have been written on a smooth surface."^[37] The Ministry of Defense had earlier tried to remove Shin from the investigative team, saying that "He is not qualified to work as part of the investigation team, as he has been spreading malicious rumors, as well as lacks expertise and has been insincere in his participation in the probe."^[38]

On 13 September 2010, the final report was issued by JIG which concluded that, "The Cheonan was split and sunk due to a shockwave and bubble effect generated by the underwater explosion of a torpedo. The detonation location was three meters to port from the center of the gas turbine room and at a depth of 6-9 meters..." Their conclusion was that the torpedo did not physically hit the ship, but the explosion was close enough and destructive enough to sink it.^[39]

Design

Armament

The ship's armament consisted of:^[5][6]

• Boeing RGM-84 Harpoon missiles
• Two Otobreda 76 mm/62 compact guns (OTO Melara)
• Two Bofors 40 mm/70 guns
• Six 12.75 in (324 mm) Mark 46 torpedoes
• Twelve Mark 9 depth charges

Propulsion

Cheonan was powered by a pair of MTU engines, which produced a total of 6,260 horsepower (4.67 MW).^[13] These engines powered two propellers, which could move the ship at a top speed of 30 knots (35 mph).^[13]

References

1. ^ Sang-Hun, Chloe (19 May 2010). "South Korea Publicly Blames the North for Ship’s Sinking". The New York Times. http://www.nytimes.com/2010/05/20/world/asia/20korea.html?ref=global-home. Retrieved 25 May 2010. 
2. ^ ^{a b} "South Korea: Torpedo probably sank warship". MSNBC. 25 April 2010. http://www.msnbc.msn.com/id/36763498/ns/world_news-asiapacific/. Retrieved 25 May 2010. 
3. ^ ^{a b} "Probe IDs torpedo that sunk Cheonan: sources". Joong Ang Daily. 20 May 2010. http://joongangdaily.joins.com/article/view.asp?aid=2920725. Retrieved 25 May 2010. 
4. ^ ^{a b c d} "South Korean navy ship sinks near sea border with North". BBC. 26 March 2010. http://news.bbc.co.uk/1/hi/world/asia-pacific/8589507.stm. Retrieved 2010-03-26. 
5. ^ ^{a b c} "Patrol Combat Corvette (PCC)". Republic of Korea Navy. http://www.navy.mil.kr/english/pds/weapon/pcc.jsp. Retrieved 26 March 2010. 
6. ^ ^{a b} "Pohang (PCC Patrol Combat Corvette) - Specifications". GlobalSecurity. 9 January 2010. http://www.globalsecurity.org/military/world/rok/pohang-specs.htm. Retrieved 27 March 2010. 
7. ^ "External Impact Likely Cause of Ship Sinking". The Korea Times. 15 April 2010. http://koreatimes.co.kr/www/news/nation/2010/04/205_64242.html. Retrieved 16 April 2010. 
8. ^ ^{a b} "'North Korean torpedo' sank South's navy ship - report". BBC News. 20 May 2010. http://news.bbc.co.uk/2/hi/world/asia_pacific/10129703.stm. Retrieved 20 May 2010. 
9. ^ North Korea rebuffs South Korea's evidence on Cheonan attack, Christian Science Monitor, May 20, 2010.
10. ^ "Presidential Statement: Attack on Republic of Korea Naval Ship ‘Cheonan’". United Nations Security Council (United Nations). 9 July 2010. S/PRST/2010/13. http://www.un.org/News/Press/docs/2010/sc9975.doc.htm. Retrieved 12 July 2010. 
11. ^ ^{a b} "Pohang (PCC Patrol Combat Corvette) - Ships". GlobalSecurity. http://www.globalsecurity.org/military/world/rok/pohang-unit.htm. Retrieved 2 April 2010. 
12. ^ Han, Da-eun (27 March 2010). "Cheonanham Specifications". Arirang News. http://www.arirang.co.kr/News/News_View.asp?nseq=101528&code=Ne2&category=2. Retrieved 28 March 2010. 
13. ^ ^{a b c} "ROKS Cheonan (PCC-772) Patrol Combat Corvette". Military Factory. http://www.militaryfactory.com/ships/detail.asp?ship_id=ROKS-Cheonan-PCC772. Retrieved 27 November 2010. 
14. ^ "Hopes fade for missing S Koreans". Al Jazeera English. 28 March 2010. http://english.aljazeera.net/news/asia-pacific/2010/03/201032720719529903.html. Retrieved 28 March 2010. 
15. ^ "S. Korean Navy ship sinking in Yellow Sea". Yonhap News. http://english.yonhapnews.co.kr/national/2010/03/26/18/0301000000AEN20100326008600320F.HTML. Retrieved 27 March 2010. 
16. ^ "Report: South Korean navy ship sinks". CNN. 27 March 2010. http://www.cnn.com/2010/WORLD/asiapcf/03/26/south.korea.ship.sinking/index.html. Retrieved 26 March 2010. 
17. ^ "유용원의 군사세계 > 토론방 > 무기" (in Korean). Chosun. http://bemil.chosun.com/nbrd/bbs/view.html?b_bbs_id=10040&pn=1&num=55251. Retrieved 25 May 2010. 
18. ^ "Poor weather halts search of South Korea sunken warship". BBC News. 31 March 2010. http://news.bbc.co.uk/1/hi/world/asia-pacific/8596081.stm. Retrieved 2010-03-31. 
19. ^ Mark TranSi-Young Lee and Hyung-Jin Kim (28 March 2010). "Angry families visit site of sunken SKorean ship". The Associated Press. http://www.google.com/hostednews/ap/article/ALeqM5jQydsIWmNQZpwRriADac51u5rx8gD9ENJ9B83. Retrieved 28 March 2010. 
20. ^ ^{a b} Lee, Tae-hoon (28 March 2010). "More Questions Raised Than Answered Over Sunken Ship". The Korea Times. http://www.koreatimes.co.kr/www/news/nation/2010/03/113_63157.html. Retrieved 28 March 2010. 
21. ^ "North Korea denies it sank South's navy ship". Reuters. 17 April 2010. http://www.reuters.com/article/idUSTRE63G0CN20100417. Retrieved 18 April 2010. 
22. ^ Crilly, Rob (26 March 2010). "South Korea investigates whether North involved in ship sinking". The Daily Telegraph (London). http://www.telegraph.co.uk/news/worldnews/asia/southkorea/7528520/South-Korea-investigates-whether-North-involved-in-ship-sinking.html. Retrieved 26 March 2010. 
23. ^ "Hopes fading for South Korea sailors". BBC News. 27 March 2010. http://news.bbc.co.uk/1/hi/world/asia-pacific/8590515.stm. Retrieved 27 March 2010. 
24. ^ South Korea rules out navy ship sunk by North Korea, Reuters, Jo Yonghak, 27 March 2010
25. ^ "Sunken section of South Korean naval vessel found". BBC News. 29 March 2010. http://news.bbc.co.uk/1/hi/world/asia-pacific/8592175.stm. Retrieved 29 March 2010. 
26. ^ "South Koreans hold out hope for sailors missing after ship explosion". Stars and Stripes. http://www.stripes.com/article.asp?section=104&article=69124. Retrieved 3 April 2010. 
27. ^ "Diver dies at South Korean warship rescue site". BBC News. 30 March 2010. http://news.bbc.co.uk/1/hi/world/asia-pacific/8594226.stm. Retrieved 30 March 2010. 
28. ^ ^{a b c} Kwang-Tae Kim (3 April 2010). "SKorea stops underwater search for missing sailors". The Associated Press. http://www.google.com/hostednews/ap/article/ALeqM5jQydsIWmNQZpwRriADac51u5rx8gD9ERMARG1. Retrieved 2010-04-03. 
29. ^ "Nine missing as S Korean boat sinks in warship search". BBC News Online. 3 April 2010. http://news.bbc.co.uk/2/hi/asia-pacific/8601540.stm. Retrieved 3 April 2010. 
30. ^ ^{a b} "Stern of South Korea naval ship lifted from sea bed". BBC News. 15 April 2010. http://news.bbc.co.uk/2/hi/asia-pacific/8621418.stm. Retrieved 15 April 2010. 
31. ^ Lee, Tae-hoon (23 April 2010). "Front Half of Cheonan to Be Raised Today". http://www.koreatimes.co.kr/www/news/nation/2010/04/116_64756.html. Retrieved 25 May 2010. 
32. ^ Sang-Hun, Choe (25 April 2010). "South Korea Cites Torpedo Attack in Ship Sinking". The New York Times. http://www.nytimes.com/2010/04/26/world/asia/26korea.html. Retrieved 25 April 2010. 
33. ^ "Investigation Result on the Sinking of ROKS "Cheonan" by The Joint Civilian-Military Investigation Group". BBC News. 20 May 2010. http://news.bbc.co.uk/nol/shared/bsp/hi/pdfs/20_05_10jigreport.pdf. Retrieved 28 November 2010. 
34. ^ ^{a b} "Investigation Result on the Sinking of ROKS "Cheonan" - report". Ministry of National Defense R.O.K.. http://www.mnd.go.kr/mndEng_2009/WhatsNew/RecentNews/index.jsp. Retrieved 20 May 2010. 
35. ^ "Questions Raised Following Cheonan Announcement". The Hankyoreh. http://english.hani.co.kr/arti/english_edition/e_national/421856.html. Retrieved 28 November 2010. 
36. ^ "Questions Raised About 'Smoking Gun'". The Korea Times. http://www.koreatimes.co.kr/www/news/nation/2010/05/205_66234.html. Retrieved 28 November 2010. 
37. ^ "Probe member summoned on false rumor allegations". JoonAng Daily. 29 May 2010. http://joongangdaily.joins.com/article/view.asp?aid=2921120. Retrieved 28 November 2010. 
38. ^ "Gov't seeks to replace Cheonan investigator". The Korea Times. 13 May 2010. http://www.koreatimes.co.kr/www/news/nation/2010/10/116_65828.html. Retrieved 28 November 2010. 
39. ^ "Seoul reaffirms North Korea’s torpedo attack in final report". Korea Times. 13 September 2010. http://www.koreatimes.co.kr/www/news/nation/2010/09/205_72997.html. Retrieved 13 Sep 2010. 

External links

Korea portal

• Korean Navy page on Pohang-class corvettes