What type of canal lock did Leonardo da Vinci develop to control water levels?

Leonardo da Vinci developed a miter gate lock to control water levels in canals.

While working on canal projects in Lombardy, Leonardo studied ways to move boats between waterways at different elevations. His lock designs used paired gates meeting at an angle, a form known as a miter gate. Water pressure pushed the closed gates tightly toward each other, helping them resist the force of the water.

Leonardo’s canal work was connected with improvements to the Naviglio di San Marco system in Milan. He did not invent the entire concept of canal locks, and earlier forms of locks existed in Europe and China. His importance lies in refining mechanisms, documenting their operation, and applying engineering analysis to practical water transport.

Modern navigation locks still use the same basic sequence: close gates, change the chamber’s water level, and open the opposite gates. Leonardo’s notebooks include many hydraulic studies, so individual sketches should not automatically be treated as completed public works.