The government-appointed investigation team concluded Thursday that an external underwater explosion caused by a heavy torpedo manufactured by North Korea split apart and sank the South Korean Navy corvette Cheonan in the West Sea on March 26.
The multinational team released its final result of the nearly two-month probe, holding the communist state culpable for the disaster that left 46 sailors either dead or missing. The North immediately dismissed the findings as "fabrications."
Presenting simulation test results and torpedo parts collected from the scene of the sinking, the team said the torpedo with an explosive weight of 200-300 kilograms generated the explosion, which occurred at a depth of six to nine meters, roughly three meters left of the center of the ship?s gas turbine room.
Last Saturday, a civilian dredging ship -- mobilized to collect evidence at the scene near the western inter-Korean sea border -- pulled up the parts of the North Korean torpedo, which the team calls "conclusive evidence."
"We have collected propulsion parts (of the torpedo), including a propulsion motor with propellers and a steering section," said Yoon Duk-yong, co-head of the investigation team during a press conference at the Ministry of National Defense.
"They perfectly match the schematics of the CHT-02D torpedo included in introductory brochures provided to foreign countries by North Korea for export purposes."
The team discovered a mark in Korean at the end of the propulsion section of the torpedo, which reads "No. 1." The mark is "consistent" with that of the North Korean training torpedo the South obtained seven years ago off its southern coast, it said.
The torpedo in point is a heavyweight passive acoustic homing torpedo measuring about 53 centimeters in diameter and weighing 1.7 tons with a net explosive weight of about 250 kilograms.
Yoon added that the team's investigation shows that a strong shockwave and bubble jet effect caused the ship to be torn in two.
"A sentry on the shore of Baengnyeong Island stated that he witnessed a roughly 100-meter-high pillar of white light for two to three seconds. The phenomenon is consistent with damage resulting from a shockwave and bubble jet effect," Yoon said.
The team judges that a Yeono-class midget submarine fired the torpedo.
It has found that a few small submarines and a mother ship supporting them left a North Korean naval base in the West Sea two to three days prior to the attack and returned to their port two to three days after the attack.
"We also confirmed that all submarines from neighboring countries were either in or near their respective home bases at the time of the incident. This is confirmed by the multinational combined intelligence task force comprised of five states including the U.S., Australia, Canada and the U.K.," Yoon said.
According to the intelligence team, the North has a fleet of some 70 submarines including 20 1,800-ton Romeo-class submarines, 40 3,000-ton Sango-class submarines and 10 midget submarines, including 130-ton Yeono-class submarines.
The investigation team believes that the submarine took a detour to launch an attack in the West Sea.
"It is presumed that the submarine took a detour on the outskirts of the West Sea. For the fatal attack, it appears that the North identified its target at night and mounted the attack at close range," said Air Force Lieutenant Gen. Hwang Won-dong who headed the investigation team's intelligence analysis section.
"After the provocation, the submarine appears to have swiftly moved away from the scene and returned (to its home port) using the same infiltration route."
The Yeono-class submarine, which the North has built for export purposes, is equipped with high-end military devices and has a special structure for stealthy operations, Hwang said.
Hwang added that the North may have previously conducted an exercise in its waters in preparation for the torpedo attack.
The North possesses a variety of torpedoes including straight-running, acoustic and wake homing torpedoes with a net explosive weight of some 200-300 kilograms, according to the intelligence team.
By inviting international experts in the investigation, Seoul has been striving to ensure objectivity and fairness in the investigation with a view to securing international support and recognition in the result.
The team is comprised of 25 experts from 10 top Korean agencies, 22 military experts, three experts recommended by the National Assembly, and 24 foreign experts from the U.S., Australia, Britain and Sweden.
The foreign experts said that they have closely cooperated with the investigation and agreed with the investigation result.
The team is composed of four subordinate teams - the scientific investigation team, the explosive analysis team, the ship structure management team and the intelligence analysis team.
- The Korea Herald/Asia News Network