What type of bridge did Leonardo da Vinci design to rotate for military transport?

Leonardo da Vinci designed a revolving bridge for military transport. The bridge could be rotated to open or close a crossing, allowing troops and equipment to pass while making the structure easier to relocate.

Leonardo’s military bridge studies emphasized speed, portability, and control of waterways. A revolving design offered a tactical advantage because it could serve as a temporary crossing and then be moved aside when necessary. His notebooks contain several bridge concepts, including lightweight structures and bridges supported by arched forms.

The revolving bridge should not be confused with Leonardo’s proposed single-span bridge for Sultan Bayezid II. That project was a permanent Golden Horn crossing, whereas the revolving bridge belonged to mobile military engineering. As with many of Leonardo’s designs, surviving drawings document the concept more securely than any completed historical example.