What Leonardo da Vinci bridge was designed to swing or turn aside to let ships pass?

Leonardo da Vinci designed a revolving bridge that could turn aside to let ships pass.

The bridge appears in Leonardo’s engineering studies of the late 15th century. Its central idea was a movable span mounted so that it could rotate away from a waterway, reopening the channel after people or troops had crossed. This made the design useful both as transport infrastructure and as a military bridge.

Leonardo’s bridge studies often emphasized rapid construction, portability, and efficient movement. A revolving span could be assembled quickly and then moved without dismantling the whole bridge. The concept belongs to the same broad body of work in which he examined canals, locks, roads, and defensive engineering.

The bridge should not be confused with a drawbridge, whose span normally rises on hinges. Leonardo’s design is identified by its turning movement, although surviving drawings represent proposals rather than a documented completed structure.