What kind of lock did Leonardo da Vinci design for canals?

Leonardo da Vinci designed a canal lock using miter gates to control water levels and boat passage.

A lock allows boats to move between waterways at different elevations. Leonardo's design used two gates meeting at an angle, with the water pressure helping press the gates together when the chamber was filled. This arrangement is the defining principle of a miter gate lock and became a major improvement in canal engineering.

Leonardo worked on canal projects in northern Italy, including schemes associated with Milan. His drawings show careful attention to water flow, gate movement, and the practical problem of raising or lowering boats without draining an entire canal section.

Leonardo did not invent every element of canal-lock technology. Earlier locks existed in Europe and Asia, and other engineers contributed to their development. His contribution was a particularly influential refinement and documentation of mechanisms that made navigation through uneven terrain more efficient.