What type of bridge did Leonardo da Vinci design to stand without central supports?

Leonardo da Vinci designed a self-supporting bridge that could stand without central supports.

The bridge used interlocking timbers arranged so that the pieces held one another in place. Its stability came from the geometry and compression of the assembled parts rather than from nails, ropes, or pillars placed in the middle of the span. This made it potentially useful where soldiers needed to cross a gap quickly.

Leonardo’s notebooks contain several bridge studies, reflecting his interest in military engineering and temporary construction. A self-supporting bridge could be assembled from repeated wooden elements and then dismantled for transport. Modern demonstrations have shown that related designs can support people when built accurately.

It is easy to confuse this design with Leonardo’s revolving bridge, which was intended to swing around a pivot. The self-supporting bridge is defined by its interlocking construction and lack of a central support, not by movement.