What canal mechanism did Leonardo da Vinci design with paired gates that meet in a V shape?

Leonardo da Vinci designed a miter lock gate, whose paired leaves meet in a V shape to hold back water.

Leonardo worked on canal engineering in northern Italy and studied improved lock gates for managing differences in water level. A miter gate uses two hinged leaves that point upstream when closed. Water pressure pushes the leaves together, helping the gate seal the chamber. Opening the gates in a controlled sequence allows boats to move between canal sections at different elevations.

Earlier canal locks existed before Leonardo, so he did not invent the basic idea of a navigation lock. His importance lies in developing and refining practical hydraulic designs, including more effective gates and canal systems.

Miter gates are not the same as simple sluice gates. A sluice gate usually slides or lifts to regulate flow, while miter gates form the ends of a lock chamber and withstand water pressure through their angled meeting point.