Probably the earliest projectile throwing device used by man, the simple sling acted as an extension of the thrower's arm resulting in a mechanical advantage that increased projectile range and speed.

The sling consists of two cords and a flexible pouch. With a projectile placed in the folded pouch, the loose ends of both cords are held in one hand.

When ready, the thrower draws back his arm and swings the sling up and forward.  Just before apex, the thrower releases one cord, opening the pouch and sending the projectile on a ballistic path.

In trained hands, the sling was very accurate. Although best known for its role in the story of David and Goliath, slings were used by most, if not all, ancient armies. The Egyptian, Greek and Roman armies used slings in combat.  << Back

The staff sling was a logical advancement over the sling. Using a single pole, or staff, in place of two cords, the staff sling allowed for heavier projectiles and an increased rate of fire.

One end of the staff sling’s pouch is fixed to the staff, while the other end is free. The free end has a hole, or loop, slipped over a pin extending from the end of the staff, or notch cut into the staff.  The pin is bent, or the notch cut, so as to allow the free end of the pouch to slip off at the proper angle releasing the projectile.

Invention of the staff sling was instrumental in the development of ancient torsion catapults and eventually, trebuchets.   << Back

The torsion catapult , or onager as it is also known, is the combination of a simple sling and a large staff sling, or arm,  powered  by a bundle of twisted cord , or skein.

The onager allowed the Romans to employ fairly large projectiles at relatively long range. It fired not only solid projectiles, but also a form of grapeshot made from smaller stones baked in a clay ball.

See an Onager in Action

Introduced in the twelfth century, the trebuchet was a major advancement in warfare. Like the onager , the trebuchet employed the advantages of both the simple sling and staff sling , but used the energy of a falling weight to throw massive projectiles great distances.

The trebuchet was used primarily as a siege weapon for attacking fortifications. Because of their enormous size, trebuchets were built at the siege site, using local materials, if available.

	How Does a Trebuchet Work ?
	See a Trebuchet in Action.
	Man Powered Trebuchet