NK Heavy Torpedoes Blamed for Disaster

By Jung Sung-ki

Staff Reporter

Investigators, who believe that a torpedo attack could have sunk the Navy ship Cheonan ― breaking it in two ― are looking into the capabilities of North Korea's torpedoes, sources said Monday.

Pyongyang is believed to have four to five types of heavy torpedoes built in China and Russia.

The Type EO-3G torpedo developed by China is referred to as the probable culprit. Built in the 1980s, the torpedo is a passive homing weapon capable of hitting a ship after tracking the vessel's screws acoustically.

The Type EO-6 and ET-80A are also referred to as homing weapons that might have hit the 1,200-ton frigate near the western sea border with North Korea on the night of March 26.

Some experts downplayed the possibility of homing torpedoes, citing the low capability of North Korea's Sang-O (Shark) class submarines.

The 34-meter-long, 3.8-meter-wide Sang-O class is mainly used by special forces in infiltrating areas or laying mines. Also the sub is known not to have an advanced system to guide homing weapons.

North Korea's non-homing torpedoes include the Type 53-59 and Type 53-56, which were built in Russia and exported to China and North Korea.

On Sunday, a civilian-military team temporarily concluded that a massive air bubble shockwave, caused by a proximity explosion below the Cheonan's hull, split the ship in two.

``After a visual examination of the inside and outside of the broken section, we've concluded that there must have been an underwater explosion,'' Yoon Duk-yong, co-head of the 130-member investigation team, said.

``Given the appearance, moreover, it is most likely to have been a non-contact explosion, not a contact blast,'' said Yoon, a professor emeritus at the Korea Advanced Institute of Science and Technology (KAIST). ``The exact location and power of the explosion will be discovered through further analysis and simulations.''

북한 중어뢰 피격 가능성

정부 합동조사단은 천안함이 어뢰에 의해 피격됐을 가능성에 무게를 두는 가운데 북한의 어뢰 능력에 살펴보고 있다.

대략적으로 북한은 4가지 종류의 중국.러시아산 어뢰를 보유하고 있는 것으로 알려진다.

1980년대에 제조된 중국제 어-3G 어뢰는 수동 음향 어뢰로서 선체의 스크루에서 발생하는 음향을 추적하여 타격하는 어뢰이다. 이와 함께 최근 개발된 어-6 대함 어뢰 역시 천안함 침몰의 원인으로 지목되고 있다.

하지만 일부 전문가들은 북한이 상어급 잠수함으로 침투했다는 가정하에 유도식 수동 음향 어뢰의 가능성을 낮게 보고 있다. 상어급 잠수함은 북한 특수부대 병력들이 남한으로 침투하거나 기뢰를 매설하는데 주로 이용되지만 어뢰를 유도해 주는 시스템은 미비한 것으로 알려진다.

직주식 북한 어뢰로는 러시아에서 개발돼 중국과 북한으로 수출된 것으로 보이는 53-39 또는 53-56 어뢰가 있다.