Leonardo da Vinci designed a canal lock to lift boats between sections of water at different levels.
Leonardo worked on canal engineering in northern Italy, especially around Milan, where canals supported transport, irrigation, and construction. His lock designs used gates and chambers to control water levels. A boat could enter a chamber, the gates could be closed, and water could then be added or released until the boat reached the level of the next canal section.
Leonardo did not invent the general principle of the canal lock. Earlier locks existed in Europe and Asia, and the important Milanese canal system developed through the work of several engineers. Leonardo’s contribution was to improve and document practical lock mechanisms, including mitre gates and arrangements for managing water flow.
The system is often confused with a ship lift, which raises a vessel mechanically or in a water-filled platform. A canal lock instead changes the water level inside a chamber. That simple principle remains fundamental to inland navigation.