Hu dun pao (虎蹲砲) is the name of two different missile weapons in Chinese history. In theSong dynasty (960–1279), it was atrebuchet and its name is translated into English asCrouching Tiger Trebuchet; in theMing dynasty (1368–1644), the name was given to a type ofbombard and it is known in English asCrouching Tiger Cannon.
According to the Song dynasty military compendiumWujing Zongyao (published 1044), thehu dun pao is depicted as a traction trebuchet with a triangular frame.[1] It is operated by a dedicated corps of 70 haulers, who took turns pulling the ropes attached to the trebutchet arm to send the projectile, a 16-pound (7.3 kg) stone or bomb, into flight.[2] It has a range of 85 yards (78 m).[1]
TheAnnales ianuenses, the official history ofGenoa, carries drawings oftrabuchium, a counterweighted trebuchet with triangular supporting trusses, thatSinologistJoseph Needham considers to be derived from or related to the Chinese "Crouching Tiger Trebuchet".[3] Similar triangular-framed trebutchets are found inByzantine sources aslabdarea (lambda-shaped machines) and as "Turkish trebuchets" (manjanīq turkī) byMardi ibn Ali al-Tarsusi and theTemplar of Tyre.[4]
Mao Yuanyi (茅元儀; 1594–1640), the compiler of the Ming dynasty military treatiseWubei Zhi, considered the "Crouching Tiger Trebuchet" as an ancestor to thecannon along with other bomb-throwing trebuchets.[5]
By the publication of the 1350 editionHuolongjing during the Ming dynasty, the meaning of the characterpao 砲 changed from "trebuchet" to "cannon",[6] mirroring thedevelopment of gunpowder artillery in China.[7] Likewise, "hu dun pao" came to refer to an early Chinese iron cannon in the same text.[5] TheHulongjing describes the "Crouching Tiger Cannon" as thus:[8]
It measures 2 feet in length and weighs 36catties (21.6 kg). Each of the (iron) staples (used to pin down the cannon in position) weighs 3 catties and measures 1 ft 2 in. in length. The six cast-iron bands (for strengthening the barrel) each measure 1 ft 1 in. and weigh 3 catties. The barrel holds 100 bullets, each weighing 0.5 oz., and 3 oz. of (gun-)powder.
According to this description and the illustration in theHuolongjing, the "Crouching Tiger Cannon" was a small cannon that was propped up at the muzzle end and pinned to the ground to deaden therecoil. This setup supposedly resembles a crouching tiger, giving the cannon its name like its trebuchet predecessor. The barrel holding 100 bullets could mean the "Crouching Tiger Cannon" fired pellets, or that the bullets could have been placed in a bag asgrapeshot.[8]
Of special note are the iron bands acting as reinforcements around the cannon—they indicated that the "Crouching Tiger Cannon" was abuilt-upcast-iron gun.[9] The iron bands were shrunk onto thebarrel while red hot, and the consistently fitting bands show that the Ming Chinese foundrymen had masteredquenching in mass-production conditions. The grounding pins were cast separately.[9]
According toQi Jiguang'sTreatise on Military Training (練兵實紀,Lianbing Shiji) of 1568, the "Crouching Tiger Cannon" was placed at various points on the Chinese frontier since the beginning of the Ming dynasty.[10] They were still used during theImjin War of 1592–98, where their deployment was crucial in theretaking of Pyongyang (1593) from the Japanese invaders.[11] Following the Imjin War, a typicalFujianese war junk (福船,fuchuan), the standard ship of the Ming navy, would carry the "Crouching Tiger Cannon" alongside heavy cannons,breech-loading cannons,falconets, andfire lances.[12]