"The manner in which certain bridges should be placed with rapidity, suitable for fleeing from or pursuing the enemy: This bridge is very convenient and quick, but give it those hooks every 6 braccia, as you see depicted in front. And when you have fixed the pieces of wood on
the fork, with the tips projecting in the air, that is, of the timbers, and these, of their weight, are bending toward the water, lift them back up with the jack, as depicted above, and bind them. Then put the next fork afterward, and so continue, little by little."
The idea for this bridge comes from Leonardo's studies on the construction of temporary military bridges to be quick to construct and dismantle using easily available materials. Leonardo studies and draws a provisional bridge constituted of a system of bridge beams supported by a row of trestles or armoring, simple in one case and double in the other. The bridge beams partially cover it, leaving uncovered one section of it to show the succession of the constructional phases.
The model is based on the drawing:
- Codex Atlanticus f. 55 r. (1480-1482)
Milano, Biblioteca Ambrosiana