I designed this bridge with Tinkercad, and use eight of them (one is movable) in a model of the Seven Bridges of Königsberg for the Mathamuseum.
FWIW, our ball chain climbs over the walls, and I have had to add escutcheon pin bollards. My bridges would be improved by adding posts or more abrupt ends.
Printed with supports using Slic3r for Prusa in PETG.
The author hasn't provided the model origin yet.