What type of bridge did Leonardo da Vinci design to support itself without ropes or piers?

Leonardo da Vinci designed a self-supporting bridge that could stand without ropes or piers.

The bridge used interlocking timbers arranged so that the pieces pressed against one another and stabilized the whole structure. Its portability made it suitable for military crossings, where soldiers might need to assemble a temporary bridge without permanent foundations or specialized tools.

Leonardo’s design demonstrates a practical understanding of compression and friction. The pieces had to be positioned correctly: the structure’s stability came from their geometry and mutual pressure rather than from nails, ropes, or masonry supports. Modern demonstrations show that the concept can be assembled from ordinary beams.

It is not the same as a suspension bridge, whose deck hangs from cables, or a pontoon bridge, which floats on boats or other buoyant supports. Leonardo produced several bridge concepts, and this one is specifically identified by its self-supporting construction.