Mobile elevator

From Virgilio riccardiano, Ms. Ricc. 492, f. 72r.


Construction, loading and unloading materials.

Double wheeled manual winch.

Crane with a pyramidal structure and a square base, which could have a height in the order of 10-12 meters. Elevating machines with similar structures are represented in the notebooks and treatises of Tuscan engineers from the middle of the fifteenth century (ex. Taccola) and later, and also in the manuscripts coming from Germany , but no engineer plays this lift in the manner described by Apollonio di Giovanni, author of this miniature. This crane is a very simple construction machine, with the only element of mechanical complexity represented by the height-adjustable vertical arm. The lack of a hoist greatly limits the power of the crane when the load is lifted from the central winch. However, the possible presence in the miniature of what seems to be a second pulley at the rear of the antenna , can make us think to a double use of the crane according to the magnitude of the load, by supplementing it with an external winch - perhaps a Treadmill wheel model - in case of a higher power demand. The frame of the base, on which the wheels are mounted, is devoid of the front and rear cross members , perhaps to allow the crane to move forward and backward on the work site, or to facilitate working at its base. The crane is represented in the act of placing a block of stone on the facade of the Palazzo Medici Riccardi: the size of the stone does not seem to be consistent with the load capacity of the crane used with the central winch.


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