Trebuchet, Early Siege Artillery
Here we have the opening act in the development of early artillery. A trebuchet was in essence a siege device, and it was an advance on the simple design of a catapult, within which classification the Ballista is included. It preceded cannon as the preferred means of launching a heavy projectile, typically against the walls of a castle or fortification. The word derives from the French trébuchet or ‘trap’, but the origins of the device are Chinese.
Early Chinese examples, which first appear in the historical record during the fourth century BCE, tended to use manpower to deploy the arm, as did later examples adopted by the Byzantines in the mid-sixth century CE. The more complex, and effective use of a counter-weight to swing the arm tend to appear once the system had been adopted by Christian and Muslim armies in the twelfth century CE. This began the evolution of highly complex versions that were capable of hurling a heavy projectile considerable distances.
The French, of course, adopted it during the early Middle Ages, giving it its universal name, but when it reached England, it was referred to as the ‘Trebucket’, or more formally, the Ingenium, or ingenious device in the Latin. It was in fact introduced to England in 1216, when Louis, Dauphin of France, crossed the English channel and laid siege to English port town of Dover. The trebuchet was used against the walls of Dover castle, and while it failed to breach the wall, English engineers observing from the turrets were extremely impressed. Once the French had given up and gone home, the English set about building an even more massive version, called ‘Warwolf’, which used a system of human-powered treadmills to winch the arm into position.
The physics of a trebuchet are relatively simple, and once fine-tuned, could be extremely effective. It consisted of a lever and a sling, with the lever pivoted at a point about a sixth of its length. A heavy weight was positioned at the short end, and when fired, the choreographed release of the throwing arm, in combination with the ‘whip’ of the sling, produced an elegant ‘hurl’ that sent whatever had been placed in the sling in the direction of the enemy.
The object thrown, of course, was usually a heavy stone, but casks of burning tar were also very effective when tossed over the walls and into the city beyond, and superheated gravel or sand was another popular version, which, when sprayed on the enemy, would get under armor and cause great distress. Another common trick was to load up the sling with rotting corpses and other contaminated detritus to spread disease within the besieged city.
The Trebuchet was certainly a fearsome and effective weapon, which passed out of common in war with the arrival gunpowder and ballistics, but its fascinates students of warfare, and the evolution of trebuchet design continues to this day.