Leonardo da Vinci improved the canal lock by using two gates to control water levels, a design known as a miter lock.
A miter lock has two gates that meet in a V shape, with the point facing the higher water. Water pressure pushes the gates together, helping them resist the force of the water. This arrangement became an important feature of navigation canals.
Leonardo worked on canal engineering in northern Italy and is associated with improvements to lock mechanisms, including the use of hinged gates. His studies addressed how boats could move between waterways at different elevations without constructing a single steep channel.
The term “miter lock” describes the gate arrangement rather than a unique Leonardo invention. Leonardo did not invent every part of the canal lock, and earlier locks existed in Europe. His contribution is commonly connected with refining practical lock design and documenting hydraulic engineering.