Leonardo designed various instruments for use during the siege of a city, including a movable ladder for assaulting the city walls.
This stairway is fixed upon a trestle, on which an endless screw is mounted, activated by a crank. The screw powers a large wheel with toothing partway around, which changes the inclination of the ladder as it turns on its shaft. Once resting on the city walls, the ladder cannot be overturned by the defenders on account of the stopping mechanism that is provided by the wheel’s teeth, fitted into the threading of the endless screw.
Technical informations
Type of exhibit
Model
Collection
Material
Carved walnut wood, wrought iron
Measures
Width: 200 cm; Length: 26 cm; Depth: 105 cm.
Storage location
Relationship with the original work
Source: Leonardo da Vinci, Codex Foster I, f. 46 v
Location
Museo Leonardiano, Counts Guidi's castle, ground floor
Last update: 10 November 2025, 12:52