What type of canal gate is Leonardo da Vinci often credited with improving?

Leonardo da Vinci is often credited with improving the mitre gate used in canal locks.

A mitre gate consists of two gates that meet at an angle pointing upstream. Water pressure pushes the closed gates together, helping them resist the force of the water. This makes the arrangement especially useful for controlling levels in navigable canals.

Leonardo studied canal engineering in northern Italy, where locks were essential for moving boats through changing water levels. His work is associated with improvements to lock gates and canal systems around Milan, although the broader history of the mitre gate involves earlier engineering traditions.

The gate is not simply a floodgate that blocks water. In a lock, paired mitre gates help create a chamber whose water level can be raised or lowered so boats can pass between sections of canal.