What type of lock gate did Leonardo da Vinci use in canal designs?

Leonardo da Vinci used a mitre gate in his canal designs.

A mitre gate consists of two hinged leaves that meet at an angle, usually pointing upstream. Water pressure pushes the leaves together at the central joint, helping the gate resist the force of the water. Leonardo studied and improved canal-lock mechanisms while working in northern Italy.

His hydraulic engineering was connected with the canals around Milan, including the Naviglio system. Canal locks allowed boats to move between sections of water at different elevations, while gates controlled the flow during each stage of the passage. Leonardo’s drawings show careful attention to water pressure, hinges, and gate operation.

The word “lock” refers to the whole chamber and operating system, whereas a mitre gate is a particular gate design used in a lock. That distinction matters because Leonardo worked on many parts of canal engineering, not only on the gate leaves themselves.