Which Leonardo da Vinci invention used three separate barrels to fire several cannon shots in succession?

Leonardo da Vinci's triple-barrel cannon used three separate barrels to fire several cannon shots in succession.

Leonardo explored multi-barreled artillery as part of his military engineering work in the late fifteenth century. A three-barreled arrangement could allow one group of barrels to be fired while another was being loaded or repositioned. The concept aimed to improve sustained fire compared with a single cannon, though it was a design study rather than a clearly documented battlefield weapon built and deployed by Leonardo.

Renaissance armies were already experimenting with ways to make gunpowder artillery more mobile and practical. Leonardo's sketches show his interest in combining firepower with mechanisms for aiming, loading, and movement. His proposals often blended plausible engineering with speculative improvements.

This weapon is sometimes mixed up with Leonardo's giant crossbow or his famous armored vehicle. The triple-barrel cannon was an artillery concept, not a handheld firearm and not a machine gun in the modern sense.