What movable military bridge did Leonardo da Vinci design to swing around a pivot?

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

The bridge was conceived as a rapid military crossing. Mounted on a central support, it could be rotated into position over a waterway or gap and then moved away when troops had crossed. Leonardo’s drawings show attention to balance, counterweights, and mechanisms that would help one person or a small crew operate it.

The design belongs to Leonardo’s broader work on military engineering. Portable bridges were strategically valuable because armies needed to cross rivers without constructing permanent infrastructure. A revolving mechanism could also make the bridge easier to deploy and remove than a fixed structure.

This invention is not the same as Leonardo’s self-supporting bridge. The self-supporting design depends on interlocking parts and has no central support, while the revolving bridge depends on a pivot and is specifically intended to move around it.