Leonardo da Vinci designed a swing bridge with a movable section for boats to pass.
A swing bridge rotates horizontally around a vertical pivot. When closed, it carries people or vehicles across a waterway; when opened, its span turns aside to create a navigable channel. Leonardo’s bridge studies included portable and military designs as well as structures intended for canals and changing traffic needs.
His movable bridge concepts reflected Renaissance engineering concerns about speed, transport, and military mobility. A bridge that could be assembled, moved, or opened offered advantages over a permanently fixed crossing. Leonardo also designed compact bridges that could be carried and deployed by armies.
A swing bridge is different from a bascule bridge, which rotates upward around a horizontal axis. It is also different from a lift bridge, whose span rises vertically. These related terms are often mixed up when Leonardo’s bridge sketches are discussed.