On Ships, Torpedoes, and Koreas

North and South Korea are at it again. A South Korean ship, allegedly in poor state of repair, sinks rather close to Northern shores, but still in Southern territorial waters. The official report concludes the ship was torpedoed by a mini-sub. This can only mean one thing! Or can it...?


Baengnyeong Island is a small island only 16 km off the North Korean coast, yet 160 km from Southern territory, north of the Armistice Line, making it technically Northern territory. This, coupled with the presence of rich fishing grounds in the area, has been a source of continuous tension between the two states, resulting in frequent clashes around the island, dubbed the Crab Wars.


The corvette, Cheonan, was on a patrol mission on March 26, when an explosion occurred near the ship's stern, which resulted in the ship rapidly breaking up, and going down at 1230 UTC, with 46 sailors unaccounted for. Their bodies were later found when the hull was salvaged. What lends some credibility to the Southern claim is that the Cheonan radioed back to Fleet Command that they were under attack. The Cheonan's sister ship, the Sokcho, returned fire on an unidentified radar image, which was, however, later confirmed to have been a flock of birds.


Once the wreckage was salvaged, South Korea, the US, and Canada formed an investigation team to determine the cause of the sinking. While up to that point, Korean authorities gave conflicting reports of the cause, the joint investigative team determined that the most likely cause of the breakup was a 'bubble jet' from a proximate torpedo explosion, not a direct hit. Additionally, traces of a high explosive, RDX, were found in May. 
The 'bubble jet' effect occurs when a mine or torpedo detonates without impacting the hull, resulting in a 'hole' in the water. This hole collapses rapidly from the bottom to form a column of water that can go as high as a hundred meters, and bores a hole through the ship, flooding several compartments at once, or breaking up the hull.
Also of note are the traces of RDX on the hull. RDX, or Royal Demolitions eXplosive, or Research Department (composition) X, is a British military high explosive, one of the most powerful and brisant of all high explosives currently in use, and a major component in many explosive mixtures, such as the fabled Semtex. Although household production is possible, it requires skill and courage, as, although RDX itself is very stable, intermediate products are prone to detonation at the slightest agitation.


The remnants of the specific weapon used for the attack, a CHT-02D torpedo, were recovered. The weapon is of North Korean manufacture, lending further credibility to the Cheonan's captain's testimony. US intelligence showed that, despite previous attestations that no extraordinary activity was noted, a group of small submarines with support units left port shortly before the attack.


In light of this incident, South Korea yesterday suspended nearly all trade with North Korea, and took part in a joint naval exercise with the United States in the area. According to the New York Times, this was the most serious action South Korea could take without resorting to actual military maneuvers. In response, North Korea placed its military forces on high alert, preparing for a possible invasion. Psychological warfare is also under consideration  as propaganda and loudspeaker installations at the Demilitarized Zone to demoralize Northern patrols, to which the North has promised retaliation in force.
Illustrating the severity of the crisis is the fact that Ba-Ki Moon requested that the Security Council "fulfill its responsibility for the maintenance of international peace and security, will take measures appropriate to the gravity of the situation", and take action against North Korea.


This incident may just prove to be the spark that sets the Korean Peninsula aflame. We must not forget that North Korea is an unofficial nuclear power, with all the powers and none of the responsibilities that come with the title, and a dangerously unstable dictator keeping his finger on the proverbial Button, who has not hesitated to defy international directives before, and will probably not hesitate to defy them now.


For all our sakes, let us hope that this conflict can be resolved peacefully, or at the very least, without resorting to nuclear weapons on either side.