Medieval Catapults
Evolution
Two major developments occurred in the area of siege artillery during the late middle ages. The first, the introduction of the crossbow to England by the Norman invaders, occurred in 1066.43 The Norman crossbow functioned and was used exactly like the Arcuballista of the late Roman Empire, indicating the maintenance of this concept in western continental Europe where the Normans lived prior to their invasion of England. Cocked by hand or with a winch mechanism and fired from the shoulder, a crossbow loaded with a metal tipped arrow was capable of piercing even the thickest armor.
The crossbow's role in warfare ended in large part at the beginning of the 16th century, due to the advent of gun powder weapons, but still remains in recreational use around the world today.
The second development was the trebuchet in the 12th century. The trebuchet was a giant stone throwing engine powered by gravity in the place of tension or torsion. A trebuchet built and currently maintained in England with a 12,000 lbs counterpoise attached to it's arm is capable of throwing a 1400 lbs car 87 yards and 100 lbs iron weight 235 yards 44 Such engines wrecked havoc around Europe and were employed by the Crusaders during their sieges in the near east.
6. Sir Ralph Payne Gallwey, The Crossbow, (New York: Bramhall House, 1958) 44.
7. Ray Hutton, "Seige the Day," Car and Driver, June 1992: 94.