A mitre gate is the type of lock gate commonly associated with Leonardo da Vinci’s canal engineering.
Mitre gates consist of two gates that meet at an angle pointing toward the higher water level. Water pressure pushes the gates together, helping them seal the lock chamber when closed.
Leonardo worked on canal and water-control projects in northern Italy, especially in the service of Milanese rulers. His designs addressed changes in elevation, navigation, drainage, and the movement of construction materials.
The broad history of mitre gates is complicated, and Leonardo should not automatically be credited as their sole inventor. Earlier water-control structures existed, and the surviving evidence more securely shows Leonardo studying and improving canal technology. The term “mitre gate” refers to the gate geometry, not to a complete lock system.