What type of canal lock did Leonardo da Vinci help develop?

Leonardo da Vinci helped develop the miter lock for canals. Its paired gates meet at an angle pointing toward the higher water level, allowing water pressure to help keep them closed.

Leonardo worked on canal engineering in northern Italy, especially in connection with the waterways around Milan. Canal locks made it possible for boats to move between sections of water at different elevations. A reliable gate design was essential because the difference in water pressure could be used constructively rather than fought with a flat barrier.

The miter lock is often associated with Leonardo, but he was building on earlier hydraulic and canal traditions rather than inventing every principle alone. The name refers to the angled meeting of the gates. It is different from a single-gate or simple hinged barrier, which does not use the same opposing-gate geometry.