Leonardo da Vinci improved the canal lock by using two gates in a short chamber to raise or lower boats.
A canal lock works by isolating a section of water between two gates. A boat enters, the gates close, and the water level is changed until it matches the next section of canal. The second gate then opens, allowing the boat to continue at a different elevation. Leonardo’s designs refined this principle with practical gate and chamber arrangements.
Leonardo worked on hydraulic engineering in northern Italy, where canals were vital for transport, irrigation, and industry. His notebooks contain detailed studies of water flow, sluices, locks, canals, and mechanisms for controlling water levels.
He did not invent the basic idea of a lock from nothing, and earlier water-control systems existed. His importance lies in developing and documenting sophisticated canal-lock designs, including mitre-gate arrangements that became highly useful in European canal engineering.