Leonardo da Vinci improved the canal lock used in Milan’s canal system.
His work is associated especially with the lock at San Marco, part of the Naviglio network. A lock uses gates and a chamber to raise or lower boats between sections of water at different levels, allowing navigation where a continuous waterway is impossible.
Leonardo studied the gates, water flow, and operating arrangements in detail. His designs helped refine an existing technology rather than inventing the basic idea of the canal lock from nothing. That distinction matters because locks had earlier European precedents.
The Milanese canals served transport, irrigation, and construction needs. Leonardo’s engineering contributions therefore belonged to a wider program of practical water management, not just experimental machinery.