King Munjong’s Hwacha

Also called: Hwacha, Singijeon

King Munjong had the hwacha built — a cart that launched rocket arrows (singijeon) or guns all at once.

The juhwa rocket arrows made by Choe Mu-seon’s Office of Gunpowder Weapons in late Goryeo were improved under Sejong and renamed singijeon around 1448. These self-propelled arrows carried a gunpowder tube; they came in large, medium and small sizes, and the large ones bore an explosive charge. Their designs survive in detail in the weapons section of the Gukjo orye-ui seorye.

In 1451, the year he came to the throne, Munjong had the hwacha made: a two-wheeled cart topped with a perforated wooden frame that could fire a hundred singijeon or a set of guns at once, and that could double as a supply cart. Hwacha are said to have been used at the Battle of Haengju during the Imjin War.