Ebook: Siege engine dynamics

European journal of physics. 2005, 26, p. 561–
577. doi:10.1088/0143-0807/26/4/002A siege engine is an ancient mechanical device designed to hurl rocks or other materials at or over the walls of a besieged fortress. It was usually constructed of wood such as oak, and often strapped with iron or rope for reinforcement. The engines of classical antiquity, such as the onager, derived their power from twisted cord or metal springs. These machines were still in use in medieval times, but by 1200 C.E. had been superseded by the trebuchet. This is a counterpoise machine, powered by gravity. A projectile, connected to one end of a lever by a sling, was propelled by the action of a large counterweight (CW), attached to the other end of the lever. A medieval drawing of a trebuchet is shown in figure. Traction trebuchets were invented in China in the 5th–3rd centuries B.C.E. This early form lacked a CW; the motive power was provided by (up to 250) soldiers hauling on ropes. Despite their antiquity, the counterpoise engines are generally considered to be medieval devices, because they evolved considerably and grew very large as their use spread westward. Islamic, Byzantine and later western European engineers developed the trebuchet into a leviathan: some trebuchets threw a projectile (usually a cut stone sphere, but sometimes flaming tar or a dead horse, or human) weighing 1 ton or more and were powered by the gravitational force of a 20 ton CW. A more typical projectile mass was m = 100 kg, which could be thrown a distance of 150–350 m, depending upon the trebuchet design and upon which historical source we consult. These engines dominated siege warfare until the 16th century C.E. when efficient cannon began to supplant them. The trebuchet grew large so that it could destroy the strong curtain walls and towers of medieval Islamic and European castles, which in turn grew larger partly to counter the trebuchet—an early ‘arms race’.Другие работы Марка Денни (Mark Denny):
Denny Mark. Their arrows will darken the sun. The Evolution and Science of Ballistics - /file/1680268/
Denny Mark. Siege engine dynamics - /file/1728866/