What type of bridge did Leonardo da Vinci design to swing quickly across a river?

Leonardo da Vinci designed a revolving bridge that could swing across a river quickly.

The bridge was conceived as a portable military structure. Its deck could rotate around a central support, allowing soldiers to cross an obstacle and then clearing the route for boats or other traffic.

Leonardo emphasized speed, stability, and ease of assembly. The design included counterweights and a mechanism intended to make rotation easier, showing how he combined architectural planning with mechanical engineering.

It is sometimes confused with a drawbridge, but the key feature is horizontal rotation rather than lifting the deck upward. Leonardo’s bridge remained a design, yet later engineers built modern swing bridges using the same broad principle.