What kind of lock gate did Leonardo da Vinci develop for canals?

Leonardo da Vinci developed the mitre gate for use in canal locks.

A mitre gate consists of two hinged leaves that meet at an angle pointing upstream. Water pressure pushes the leaves together, helping the closed gate resist the force of the water. This made the arrangement practical for controlling water levels in navigation canals.

Leonardo used mitre gates in canal engineering projects connected with Milan. The design allowed boats to pass between sections of canal at different elevations, making waterways more useful for transport.

Mitre gates were not an invention limited to Leonardo alone, and earlier forms existed. His importance lies in improving and applying canal-lock engineering during the Renaissance. A mitre gate is also different from a simple sluice gate, which generally moves vertically or slides through an opening.