Submarine detoured in West Sea

By Lee Hyo-sik

Staff Reporter

A 130 ton-class North Korean submarine that fired a torpedo at the Cheonan was presumed to have gone around the West Sea to infiltrate into waters of the South without being detected, an international team of experts investigating the sinking of the warship said Thursday.

It also reported that after penetrating the South Korean waters, the submarine zeroed in on the Cheonan and launched a torpedo at close range with intent to send it to the bottom and kill those on board.

"After piecing all evidence and intelligence together, we concluded that North Korea's two submarines - a 300 ton-class submarine and a 130 ton-class submarine - were operating in the West Sea on the night of March 26," said vice-admiral Hwang Won-dong who led the intelligence analysis unit at the investigation team.

He said the investigation team concluded that it was the 130-ton class one that fired a torpedo at the Cheonan after analyzing fragments of the torpedo recovered from the scene and gathering other military intelligence.

Hwang said after the provocation, the submarine "promptly" returned to waters north of the Northern Limit Line (NLL) by backtracking the infiltration route. The communist state is known to operate about 70 large-and small-scale submarines.

'No. 1' hand-written mark

"We do not know whether the North observed the Cheonan in advance to attack it. But we believe that North Korean submarines must have undergone prior military drills, including firing a torpedo, in waters similar to those in which the South's frigate was sunk," the vice-admiral said.

He then said it is extremely difficult for the military to defend against submarines, adding the most effective countermeasure against submarines is to keep track of them by checking whether they are stationed at the base or not.

"We detected that a few small submarines and a mother ship supporting them left a North Korean naval base in the West Sea 2-3 days prior to the attack," Hwang said. "But we never expected them to penetrate our waters and attack the Cheonan. This is why we were not adequately prepared at the time of attack."

The submarine went back to its base two to three days after the attack, he said.

After securitizing the wreckage of the 1,200-ton patrol ship and other evidence collected from the scene, including the North Korean torpedo parts, the investigation team concluded that an external underwater explosion caused by the torpedo was responsible for sinking the Cheonan and killing 46 sailors.

It said the "No. 1" hand-written mark on the rear part of the torpedo collected from the sinking site is consistent with markings on a stray North Korean torpedo the South recovered seven years ago. The navy will take a range of measures to beef up its surveillance capability of North Korean submarines.