What type of bridge did Leonardo da Vinci design to fold up for military transport?

Leonardo da Vinci designed a revolving bridge that could fold or swing into a compact form for military transport.

The bridge was intended to help an army cross rivers quickly while reducing the burden of carrying a long rigid structure. Leonardo’s drawings show a lightweight span supported by a mechanism that allowed it to be opened, moved, and secured. Some versions also emphasize rapid deployment and stability.

This was a practical military-engineering concept rather than a decorative architectural exercise. Leonardo studied bridges as tools for mobility, especially in campaigns where soldiers needed to cross watercourses without waiting for permanent construction.

The revolving bridge is distinct from a drawbridge. A drawbridge normally pivots upward or is lifted, while Leonardo’s concept used a rotating arrangement to make the bridge easier to transport and deploy.