From Leonardo da Vinci, Codex Atlanticus, f. 808r.
Cover of the lantern of the dome of Santa Maria del Fiore in Florence.
Turning Crane mounted on an annular base with two series of wheels for turning and centering respectively. The traction and unloading system is made up of a winch that moves along with a block. The block is anchored to a screw-nut that slides along a threaded shaft so as to be able to move the load horizontally.
Dimensions: the measurements of this crane can be deduced through those of the parchment of the dome of Florence’s cathedral. (h = 5m, base diameter = 3.5 m), for whose construction it was built. From these measurements we can theorize that the crane reached 6-7 meters in height with a base of about 5 meters in diameter and an outreach of about 2 meters.
Reconstruction: the crane model designed by Leonardo presents in the rear two mounting winches one on top of the other, but the drawing’s approximation makes it difficult to understand if they worked together or separately. The same crane, designed by Bonaccorso Ghiberti, was equipped more simply with one winch.