Leonardo da Vinci designed a canal lock to lift boats between different canal levels.
A canal lock is a chamber between two sections of water at different elevations. Gates close the chamber, and water is added or released until the boat reaches the level of the next section. Leonardo studied lock mechanisms while working on canal and water-management projects in northern Italy.
His designs included improved gates and arrangements that could control water more efficiently. Leonardo’s work was connected with practical problems around Milan, where canals served transport, irrigation, and construction. He did not invent the general idea of locks, which existed before his lifetime, but he contributed detailed engineering studies and refinements.
A canal lock differs from a ship lift. A lock changes the water level around the boat, whereas a ship lift raises the boat mechanically or in a water-filled caisson. Leonardo’s sketches show how closely his invention studies linked mechanical design with civil engineering.