With an external explosion being cited as the most likely cause of the sinking of the Cheonan, allegations are growing that a torpedo, fired by a North Korean submarine, could have caused the disaster.
Experts say that given the shallowness of the waters near the western inter-Korean maritime border, a 325-ton shark-class submarine could have entered South Korean waters undetected.
Rep. Kim Hak-song of the ruling Grand National Party who chairs the National Assembly’s defense committee said on April 5 that he was briefed by the military that movements of two shark-class submarines at the North’s naval base in Bipagot -- some 80 kilometers north of Baengnyeong Island -- were detected before and after the incident occurred on March 26.
Kim also said the whereabouts of one of the submarines was not verified, fueling speculation that a North Korean submarine entered the South’s waters and fired a torpedo at the Cheonan, which was traveling 1.8 kilometers southwest of Baengnyeong Island.
If a shark-class submarine traveling at 13 kilometers per hour had come from Bipagot, it would have taken six to seven hours to reach the waters near Baengnyeong Island.
To avoid being detected by the South’s surveillance, the submarine might have operated only underwater. However, experts say that the submarine should come above the water periodically for air.
“It depends on how many people are aboard the vessel. The submarine should come above the water to emit carbon dioxide created by crewmembers inside,” a submarine expert told The Korea Herald on condition of anonymity.
Experts believe that if the North’s submarine had infiltrated the South’s waters, it might have moved from the waters far west of Baengnyeong Island rather than taking a route between the island and the North’s province of Hwanghae.
They believe that the North’s submarine could not take the route because of the tidal currents between the island and the province and the South’s military has been tightening its security along the route.
Experts say that given the shallowness of the waters near the western inter-Korean maritime border, a 325-ton shark-class submarine could have entered South Korean waters undetected.
Rep. Kim Hak-song of the ruling Grand National Party who chairs the National Assembly’s defense committee said on April 5 that he was briefed by the military that movements of two shark-class submarines at the North’s naval base in Bipagot -- some 80 kilometers north of Baengnyeong Island -- were detected before and after the incident occurred on March 26.
Kim also said the whereabouts of one of the submarines was not verified, fueling speculation that a North Korean submarine entered the South’s waters and fired a torpedo at the Cheonan, which was traveling 1.8 kilometers southwest of Baengnyeong Island.
If a shark-class submarine traveling at 13 kilometers per hour had come from Bipagot, it would have taken six to seven hours to reach the waters near Baengnyeong Island.
To avoid being detected by the South’s surveillance, the submarine might have operated only underwater. However, experts say that the submarine should come above the water periodically for air.
“It depends on how many people are aboard the vessel. The submarine should come above the water to emit carbon dioxide created by crewmembers inside,” a submarine expert told The Korea Herald on condition of anonymity.
Experts believe that if the North’s submarine had infiltrated the South’s waters, it might have moved from the waters far west of Baengnyeong Island rather than taking a route between the island and the North’s province of Hwanghae.
They believe that the North’s submarine could not take the route because of the tidal currents between the island and the province and the South’s military has been tightening its security along the route.
As the ill-fated ship was torn in two and sank after an explosion on its port side, experts believe a submarine operating one or two kilometers west of the ship could have fired a torpedo.
Experts believe that it would have been difficult for a submarine operating on the ship’s right side to fire any underwater weapon as the waters on the right side are shallow. The torpedo appears to be a mid-sized one with a warhead weighing more than 200 kilograms, given that the explosion ripped the 1,200-ton vessel apart.
Some question why the ship equipped with a sonar system could not have detected a torpedo.
The Defense Ministry said that the possibility of the sonar system detecting movements of a submarine or a weapon some 2 kilometers away in waters with a depth of 30 meters is about 70 percent.
Some said that to avoid being detected by the South, the North’s submarine could have entered the South’s waters by taking a route where many Chinese fishing vessels operate.
“When a submarine is located where many fishing boats are operating, it is difficult to recognize it as a submarine as it is shown as a dot along with other dots indicating the fishing boats on the radar screen,” said the source.
The shark-class submarine measures 35.5 meters in length, 3.8 meters in width and 3.2 meters in height, and can carry up to 20 crews and some four torpedoes. In 1996, a 320-ton shark-class North Korean submarine went aground off the east coast.