What kind of bridge did Leonardo da Vinci design to be assembled quickly without permanent supports?

Leonardo da Vinci designed a self-supporting bridge that could be assembled quickly without permanent supports.

The design uses interlocking wooden elements arranged so that the pieces hold one another in place. Once assembled, the structure forms a stable crossing without nails, ropes, or a central framework. Its portability made it suitable in principle for military movement across streams or gaps.

Leonardo’s bridge sketches belong to his broader study of military engineering. Renaissance rulers commissioned designs for bridges, fortifications, weapons, and transport systems, and Leonardo often emphasized speed of construction and ease of deployment.

A self-supporting bridge is different from a suspension bridge, which relies on cables, and from a drawbridge, which pivots or lifts to control access. Leonardo’s design is often built today as a demonstration of how geometry and friction can create a temporary structure.