What type of lock gate did Leonardo da Vinci study for canals?

Leonardo da Vinci studied miter gates for canal locks, the angled gates that meet in a V-shaped point.

A miter gate uses water pressure to help seal the gate when the lock chamber is full. The two leaves meet at an angle pointing toward the higher water level, so pressure pushes them together rather than forcing them open. This principle became fundamental to many navigable canal systems.

Leonardo worked on canal engineering in northern Italy, especially around Milan, where waterways supported transport and trade. His drawings and studies examined gates, channels, water flow, and methods for overcoming changes in elevation. Leonardo did not invent every element of canal-lock technology, so it is more accurate to say that he developed and studied improved designs.

Miter gates are often confused with simple sluice gates. A sluice controls water through an opening, while a lock gate closes the chamber so boats can be raised or lowered between water levels. The distinction is central to understanding Leonardo’s canal work.