Codex Atlanticus

CA f. 4 r: Rotating crane

For the project drawn on this sheet, Leonardo must have been inspired by the similar lifting machines that were in use in Brunelleschi's construction site of Santa Maria del Fiore cathedral in Florence. Thanks to a horizontal system of large screws, this crane made it possible to lift large building materials, maintaining perfect balance thanks to the play of the adjustable counterweight on the opposite side of the lifting arm. In addition to the vertical lifting movement, it was also necessary to ensure the radial one, for moving the materials from one place to another: and in fact, halfway up the enormous scaffolding, one can see the rotation platform thanks to which it was possible to turn the top of the whole machine. Finally, the other sketches in the upper part of the sheet illustrate, in detail, the various hooking systems that could ensure maximum speed and maximum safety.