A manned or stealth torpedo?In the early morning of Nov. 20, 1944, during the final stage of World War II, there was a huge explosion on the U.S.S. Mississinewa, a replenishment oil tanker for the U.S. fleet in the Pacific Ocean. It was later revealed that the ship had been hit by a manned Japanese torpedo.
The torpedo in question was a suicide weapon called a kaiten used by the Imperial Japanese army. The kaiten was designed so the pilot could sit inside and guide it, thereby increasing its accuracy. But the pilot was unable to return or escape. If the torpedo was not detonated, the pilot was expected to initiate a self-destruction device. Kaiten means “the turn toward heaven,” and, just as the name suggests, the pilot goes to heaven at the end of the mission.
Together with the kamikaze, the use of the kaiten reveals the brutal inhumanity of war. Nowadays, many kaiten torpedoes have been restored and are displayed in Japan as symbols of the former majesty of the old Japanese navy and army.
A torpedo is an explosive device and it is usually shaped like a fish. The first self-propelled torpedo was manufactured by the Austrian navy in 1866. It was a 3.35 meter tube, 36 centimeters in diameter and filled with eight kilograms of dynamite. Its energy source was compressed air. During World War I and World War II, the torpedo’s explosive power and target range increased markedly.
Torpedoes can be either unguided or wire-guided. Nowadays the Korean Navy deploys heavy torpedoes called baeksangeo, meaning white shark, and light torpedoes called cheongsangeo, or blue shark. The latter has great sound wave detectors and is capable of penetrating metal panels.
Anti-torpedo technology has been developed as well. One kind of technology, called a decoy, uses chemical substances to create so-called “bubble drapes” to interfere or hide from torpedo sound wave detectors. Another example, the nixie, is a torpedo decoy that imitates the sound of a submarine or other vessel. If a torpedo is deceived by a nixie, it is not delivered to the right location and hits the decoy instead.
After the Korean ship Cheonan sank, public interest in the stealth torpedo increased. As sound wave detectors cannot find stealth torpedoes, it is impossible to search for them or avoid them in advance.
Coincidentally, Iran, which has somewhat close relations with North Korea, announced in 2004 that it had successfully tested a torpedo with stealth technology. In 2007, Iran claimed that it had produced a submarine with stealth technology.
When the Cheonan sank there was nothing abnormal on its sound wave detector. This has raised various suspicions, such as North Korea having sent a manned torpedo or a stealth torpedo. The cause of the explosion will be discovered soon.
The writer is an editorial writer of the JoongAng Ilbo.
By Park Jong-kwon