ROKS Cheonan (PCC-772)
was a South Korea
The Republic of Korea , , is a sovereign state in East Asia, located on the southern portion of the Korean Peninsula. It is neighbored by the People's Republic of China to the west, Japan to the east, North Korea to the north, and the East China Sea and Republic of China to the south...
The Pohang class corvette is a class of general purpose vessels operated by the Republic of Korea Navy. They have served in a coastal defense role during the late Cold War and post Cold War period....
A corvette is a small, maneuverable, lightly armed warship, originally smaller than a frigate and larger than a coastal patrol craft or fast attack craft , although many recent designs resemble frigates in size and role...
of the Republic of Korea Navy
The Republic of Korea Navy or the ROK Navy is the branch of the South Korean armed forces responsible for conducting naval operations and amphibious landing operations. The ROK Navy includes the Republic of Korea Marine Corps, which is a quasi-autonomous organization...
(ROKN), commissioned in 1989. On 26 March 2010, it broke in two and sank near the sea border with North Korea
The Democratic People’s Republic of Korea , , is a country in East Asia, occupying the northern half of the Korean Peninsula. Its capital and largest city is Pyongyang. The Korean Demilitarized Zone serves as the buffer zone between North Korea and South 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
The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...
launched by a North Korean Yeono class
The Yono class submarine is a class of North Korean miniature submarines, produced for domestic use as well as for export. Also referred to as Yeono class vessels, these submarines displace 130 tons, significantly less than North Korea's larger 1,800-ton Romeo class submarines...
miniature submarine. On 9 July 2010, the United Nations Security Council
The United Nations Security Council is one of the principal organs of the United Nations and is charged with the maintenance of international peace and security. Its powers, outlined in the United Nations Charter, include the establishment of peacekeeping operations, the establishment of...
issued a Presidential Statement
A Presidential Statement is often created when the United Nations Security Council cannot reach consensus or are prevented from passing a resolution by a permanent member's veto, or threat thereof...
condemning the attack but without identifying the attacker.
was launched in November 1989 from Hyundai Heavy Industries
Hyundai Heavy Industries Co., Ltd. is the world's largest shipbuilding company, headquartered in Ulsan, South Korea. The company is a subsidiary of Hyundai Heavy Industries Group...
Ulsan , officially the Ulsan Metropolitan City, is South Korea's seventh largest metropolis with a population of over 1.1 million. It is located in the south-east of the country, neighboring Busan to the south and facing Gyeongju to the north and the Sea of Japan to the east.Ulsan is the...
, South Korea. The ship's primary mission was coastal patrol, with an emphasis on anti-submarine operations. The Cheonan
was one of the ships involved in the First Battle of Yeonpyeong in 1999. It is also known that the ship suffered slight damage on the stern in the First Battle of Yeonpyeong. The ship had been scheduled for decommissioning in 2019.
On 26 March 2010, an explosion occurred near the rear of the Cheonan
, causing the ship to break in two. The cause of this explosion was not immediately determined.
The 1,200 tonne ship started sinking at 21:20 local time
UTC+09:00 is an identifier for a time offset from UTC of +09. This time is used in:-As standard time :*East Timor*Indonesia **Moluccas**Papua and West Papua *Japan - Japan Standard Time*North Korea...
Coordinated Universal Time is the primary time standard by which the world regulates clocks and time. It is one of several closely related successors to Greenwich Mean Time. Computer servers, online services and other entities that rely on having a universally accepted time use UTC for that purpose...
) about 1 nautical miles (1.9 km) off the south-west coast of Baengnyeong Island
Baengnyeong Island is a island in Ongjin County, Incheon, South Korea, located near the Northern Limit Line. The 1953 s:Korean Armistice Agreement which ended the Korean War specified that the five islands including Baengnyeong Island would remain under United Nations Command and South Korea...
in the Yellow Sea
The Yellow Sea is the name given to the northern part of the East China Sea, which is a marginal sea of the Pacific Ocean. It is located between mainland China and the Korean Peninsula. Its name comes from the sand particles from Gobi Desert sand storms that turn the surface of the water golden...
. The island is located on the South Korean (ROK) side of the Northern Limit Line
The Northern Limit Line or North Limit Line is a disputed inter-Korea maritime demarcation line in the Yellow Sea between the Democratic People's Republic of Korea on the north, and the Republic of Korea on the south...
, the de facto
boundary dividing South from North Korea (DPRK). The ship had a crew of 104 men at the time of sinking, and a total of 58 crew were rescued. Another 46 crew were unaccounted for. Cheonan captain
Captain is the name most often given in English-speaking navies to the rank corresponding to command of the largest ships. The NATO rank code is OF-5, equivalent to an army full colonel....
Commander is a naval rank which is also sometimes used as a military title depending on the individual customs of a given military service. Commander is also used as a rank or title in some organizations outside of the armed forces, particularly in police and law enforcement.-Commander as a naval...
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. On 17 April 2010, North Korea denied any involvement in the sinking of Cheonan
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
The Republic of Korea Air Force is the air force of South Korea...
. 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. 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.
During the course of the search and rescue effort over 24 military vessels were involved, including at least three US Navy vessels, the , the USS Harpers Ferry
USS Harpers Ferry is the lead ship of her class of landing ship dock of the United States Navy. This warship was named for the town of Harpers Ferry, West Virginia, which, because of the Federal arsenal there, was an important location during the Civil War. , Harpers Ferry is commanded by...
, and the USS Shiloh
USS Shiloh is a Ticonderoga-class guided missile cruiser of the United States Navy, named in remembrance of the Battle of Shiloh in the American Civil War. She was built at the Bath Iron Works in Bath, Maine. The vessel is commanded by Captain James T...
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.
On 3 April 2010, South Korean officials said that a private fishing boat involved in the rescue operations had collided with a Cambodia
Cambodia , officially known as the Kingdom of Cambodia, is a country located in the southern portion of the Indochina Peninsula in Southeast Asia...
n freighter, sinking the fishing boat and killing at least two people, with seven reported missing. The same day, the Joint Chiefs of Staff of South Korea said that one body of the 46 missing sailors had been found.
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.
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. The same crane raised the bow portion of the Cheonan
on 24 April 2010. 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.
Cause of sinking
On 25 April 2010, South Korea's defense minister, Kim Tae-Young
General Kim Tae-young, ROKA, was the 34th Chairman of the Joint Chiefs of Staff of the Republic of Korea Armed Forces and 42nd Republic of Korea Minister of National Defense.General Kim graduated from the Republic of Korea Military Academy in 1972...
, 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.
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.
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
Hangul,Pronounced or ; Korean: 한글 Hangeul/Han'gŭl or 조선글 Chosŏn'gŭl/Joseongeul the Korean alphabet, is the native alphabet of the Korean language. It is a separate script from Hanja, the logographic Chinese characters which are also sometimes used to write Korean...
, 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. However, some have pointed out that in the North, "호"is most often used rather than "번"; and that a North Korean torpedo found seven years ago bears the marking "4호". 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. 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."
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." 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."
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.
The ship's armament consisted of:
- Boeing RGM-84 Harpoon missiles
- Two Otobreda 76 mm
The Otobreda 76 mm gun is a naval artillery piece built by the Italian defence conglomerate Otobreda. It is based on the Oto Melara 76mm/L62 Allargato, which was bigger and heavier...
/62 compact guns (OTO Melara)
- Two Bofors 40 mm/70 guns
- Six 12.75 in (324 mm) Mark 46 torpedo
Designed to attack high-performance submarines, the Mark 46 torpedo is the backbone of the U.S. Navy's lightweight ASW torpedo inventory, and is the current NATO standard. These aerial torpedoes, such as the Mark 46 Mod 5, are expected to remain in service until the year 2015...
- Twelve Mark 9 depth charge
A depth charge is an anti-submarine warfare weapon intended to destroy or cripple a target submarine by the shock of exploding near it. Most use explosives and a fuze set to go off at a preselected depth in the ocean. Depth charges can be dropped by either surface ships, patrol aircraft, or from...
was powered by a pair of MTU
MTU Friedrichshafen GmbH is a manufacturer of commercial internal combustion engines founded by Wilhelm Maybach and his son Karl Maybach in 1909...
engines, which produced a total of 6260 hp. These engines powered two propeller
A propeller is a type of fan that transmits power by converting rotational motion into thrust. A pressure difference is produced between the forward and rear surfaces of the airfoil-shaped blade, and a fluid is accelerated behind the blade. Propeller dynamics can be modeled by both Bernoulli's...
s, which could move the ship at a top speed of 30 knots (36.5 mph).