MacGyver and the Imjin War

I was puzzled when I learned that Koreans regard the time bomb as a proud addition to their list of inventions. This is because I associate the time bomb with incidents involving James Bond and MacGyver, in which the emphasis is on defusing the bomb and foiling the plans of an evil terrorist.

Although it has been used by terrorists in recent times, the time bomb was not originally a terrorist weapon. It was developed during the Imjin War (the Japanese invasion of Korea in 1592 – 1598) and projected into enemy camps and formations by catapult.

Yi Chang-son was the technician who devised the Pigyok Chinchollae (literally ‘shaking the heavens with lightning and thunder’). The following account, written by the Prime Minister of Korea after the war, tells how it was used in the recapture of Kyungju castle.

The bomb landed on the ground in front of the enemy tent, and not knowing what it was, the enemy soldiers pressed forward in order to gain a closer look. Some moments later, the bomb exploded. There was a huge sound as the explosion shook the earth, and metal shrapnel scattered in all directions. 30 were killed instantly, and many collapsed with shock. When the survivors came back to their senses, still unable understand how it had been done, they claimed it was the doing of evil spirits. On the following morning, the enemy abandoned the castle and fled.

The Implements of War, published in Japan, also documented the power of the bomb.

During the Imjin War, cannons were used extensively by the Korean army, who poured explosives upon us and inflicted great damage. At the time, our army had only just become acquainted with cannons, and we could not match the enemy.

Here, ‘explosives’ refers to the Pigyok Chincholloe and ‘cannons’ to the Wangu mortar used to fire the bomb.

In Korea, you can see the Pigyok Chincholloe at several museums, including the Yonsei University Museum, Jinju National Museum, and The War Memorial of Korea. If you, like me, are not in Korea, here is a description.

The Pigyok Chincholloe weighed about 12kg, and was cast using pig iron. Gunpowder and metal shrapnel were placed inside. The ignition device differed from regular explosives. It consisted of a bamboo cylinder with grooves carved in a spiral fashion, and the detonating fuse wound around the indentations. The time-delay before detonation was determined by the length of the fuse: the fuse was wound 10 times for a swift explosion, and 15 times if a longer delay was required.

Time bomb

(Left) Pigyok Chincholloe, 16th century, The War Memorial of Korea
(Right) Diagram of the Pigyok Chincholloe

It sounds to me like the sort of thing that MacGyver would have been proud to build.

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.