What unusual weapon did Leonardo da Vinci design with three barrels arranged side by side?

Leonardo da Vinci designed a triple-barrel cannon with three barrels arranged side by side.

The weapon was intended to increase the rate of fire compared with a single-barrel cannon. While one set of barrels was being discharged, another could potentially be prepared, reducing the delay between volleys. Leonardo’s military notebooks contain many proposals for artillery, fortifications, and battlefield equipment.

A triple-barrel arrangement also offered a compact way to place several guns on one carriage. However, Renaissance artillery remained difficult to aim, reload, and transport, and repeated firing created serious problems involving heat, smoke, and recoil.

Leonardo’s military inventions were often conceptual rather than fully developed production weapons. His sketches show that he approached warfare as a problem in mechanical design, seeking advantages through speed, concentration of fire, and improved mobility.