Leonardo da Vinci designed miter-lock gates to regulate water flow in canals.
A miter lock uses two gates that meet at an angle pointing upstream. Water pressure pushes the gates together, helping them seal the entrance. Leonardo studied and improved canal-lock arrangements during his work in northern Italy, especially while serving the Duke of Milan.
His canal engineering was connected to transportation, irrigation, and flood control. Leonardo’s notebooks record designs for gates, channels, and mechanisms that could make waterways more useful for moving goods and managing water levels. The miter-gate principle became a durable feature of canal engineering.
Leonardo did not invent every form of canal lock, and earlier locks existed in Europe. His contribution was the detailed study and refinement of practical hydraulic structures, including gates that could withstand water pressure more effectively than simpler arrangements.