fire cart[1]) was a multiple rocket launcher and an organ gun of similar design which were developed in fifteenth century Korea.

[6] Gunpowder and firearms explicitly for combating them on the sea were imported from China in 1374[7] but the necessary expertise for production was still restricted by Chinese government policy.

Local production did not begin until Ch'oe Mu-sŏn, having acquired the methods for purifying potassium nitrate from visiting Chinese merchants, accomplished it between 1374 and 1376.

Armed with forty seungja-chongtongs with fourteen in the front and thirteen on the left and right sides, it required two soldiers to operate, one firing and the other reloading.

The Japanese samurai infantry, especially in the Battle of Haengju, typically advanced in dense formations, presenting ideal targets for the hwacha.

The back side of the hwacha featured two parallel arms that allowed the operator to push and pull the machine and a vertical strip designed for in-line attacks or ground-sentry positions.

[16] The Korean army included siege engineers and blacksmiths to repair the hwacha in case of damage due to poor road conditions, bad weather, or battle.

[15] Unlike the cannons or mortars used in Western warfare during Middle Ages and the 16th century, which required heavy iron balls, hwachas fired arrows which were thin and light, making it an easy-to-maneuver siege weapon.

[16] The holes in the hwacha's launching array ranged in diameter from 2.5–4 cm (0.98–1.57 in), which allowed thin Gungdo bow-style arrows to be fired and also admitted sajeonchongtong class igniters placed in the back side of the shooting board.