Which Leonardo da Vinci design was a giant crossbow intended to launch oversized bolts?

Leonardo da Vinci’s giant crossbow design was intended to launch oversized bolts. He sketched it in the late 15th century as a spectacular siege weapon, emphasizing psychological impact as well as destructive power.

The design used a very wide bow mounted on a wheeled frame. Several mechanisms, including a winding system, were intended to draw the bowstring because the weapon was far too large for ordinary human strength. Its scale made it more ambitious than a conventional medieval crossbow.

The giant crossbow was never known to have been built and used successfully in battle. Leonardo’s military drawings often combined practical engineering with dramatic demonstrations designed to attract powerful patrons. It should not be confused with his later giant crossbow sketches or with ancient ballistae, which used different construction traditions.

The drawing is important because it shows Leonardo applying mechanical advantage, structural reinforcement, and transport considerations to a weapon concept. Modern reconstructions are interpretations of the surviving design rather than evidence of a historically deployed machine.