Leonardo da Vinci designed a swing bridge with a rotating span that could turn aside to let boats pass along a waterway.
The bridge concept belongs to Leonardo’s studies of military and civil engineering. A swing bridge pivots horizontally around a central support or pivot, moving the bridge deck out of the route used by vessels. When closed, it provides a crossing for people or vehicles; when opened, it creates a navigable passage.
Leonardo’s design was intended to be rapidly opened and closed, making it useful in military situations as well as for transport. His drawings emphasize mechanisms for rotation, balance, and support. The design was a proposal rather than evidence that Leonardo built a full-scale surviving swing bridge.
A swing bridge differs from a bascule bridge, whose deck lifts upward around a hinge, and from a drawbridge in the common medieval sense. Leonardo’s bridge studies show how he applied mechanical motion to infrastructure, not only to portable machines and weapons.