What kind of bridge did Leonardo da Vinci design to swing around a central support?

Leonardo da Vinci designed a revolving bridge that could swing around a central support.

The bridge was intended for military use and is associated with Leonardo’s work for Ludovico Sforza in Milan. A revolving bridge could be moved quickly from one bank to another and then turned aside when troops or vessels needed to pass. Leonardo’s design emphasized portability, rapid deployment, and a single pivoting movement rather than the fixed structure of a conventional stone bridge.

Its operation depended on balanced construction and a pivoting support. That combination allowed the bridge to rotate while remaining stable enough for crossing. The idea belongs to Leonardo’s broader interest in military engineering, where bridges were tools for moving armies across rivers and obstacles.

A revolving bridge is not the same as a drawbridge. A drawbridge rises or folds, usually at one end, while Leonardo’s design turns horizontally around a central point. The surviving concept is evidence of engineering planning, not proof that Leonardo personally built the bridge at full scale.