Leonardo da Vinci designed canal-lock mechanisms using hinged gates to control water levels and let boats pass between sections of a canal.
A canal lock works by enclosing a boat in a chamber. Gates close behind it, and water is added or released until the water level matches the next section. The gates can then be opened, allowing the boat to continue without requiring a canal to remain at one uniform elevation.
Leonardo studied canals, waterways, and hydraulic engineering extensively, especially in northern Italy. His work included improvements to lock-gate arrangements and practical observations about water movement.
A canal lock is different from a floodgate, which primarily controls unwanted water, and from an aqueduct, which carries water across a structure. Leonardo’s contribution belongs to the engineering of navigable waterways and efficient level changes.