Leonardo da Vinci designed catapults to hurl stones using mechanical energy stored in a spring or bent component. His notebooks include studies of war machines intended to launch projectiles farther and more powerfully than a person could throw them.
Leonardo’s catapult concepts used frames, arms, ropes, and tension systems. Some designs relied on a large flexible spring made from wood or twisted material. When released, the stored energy moved the throwing arm and sent the projectile toward a target.
A catapult is a broad term for a machine that launches objects without explosive propellant. It is not identical to a trebuchet, which uses a counterweight, or a ballista, which resembles a giant mechanical bow. Leonardo studied several kinds of artillery, so identifying the exact mechanism in a particular sketch requires care.
These designs were part of Leonardo’s military-engineering work in Renaissance Italy. They show his interest in improving range, power, and reload procedures, but surviving drawings do not demonstrate that every proposed machine was built or used successfully in combat.