What floating military device did Leonardo da Vinci design to help soldiers cross water?

Leonardo da Vinci designed a pontoon bridge to help soldiers cross water.

A pontoon bridge uses floating supports, such as boats or sealed pontoons, to carry a roadway across a river or other waterway. Leonardo’s military-engineering drawings include temporary bridges intended to be transported, assembled, and removed when necessary.

The main advantage of a pontoon bridge is speed and flexibility. It can cross water without constructing permanent foundations or waiting for masonry work. Military forces have used similar systems for centuries, especially when ordinary bridges were destroyed or unavailable.

Leonardo did not invent the general concept of floating bridges. His designs refined the arrangement of boats, platforms, ropes, and connections for military use. These proposals are distinct from his permanent Golden Horn bridge, which was planned as a fixed stone structure.