What type of bridge did Leonardo da Vinci design to fold and transport with an army?

Leonardo da Vinci designed a portable bridge to fold and transport with an army.

Leonardo’s military notebooks include a rapidly deployable bridge intended for troops crossing rivers and other obstacles. The design could be assembled or unfolded near the crossing and then moved onward as the army advanced. It was conceived as a practical tool for mobility rather than as a permanent architectural landmark.

Portable bridges were valuable in Renaissance warfare because rivers, canals, and damaged crossings could slow armies and supply trains. Leonardo’s proposal reflects the military importance of engineering, logistics, and speed. The drawings show structural members arranged to balance portability with sufficient strength for people and equipment.

The bridge is sometimes confused with Leonardo’s famous 1502 Golden Horn proposal. That design was a large permanent single-span bridge requested for Istanbul. The portable bridge was a separate military concept, smaller in purpose and designed for repeated deployment. Neither design became a documented battlefield standard under Leonardo’s command.