Rotatable crane

Rotatable crane

Inv. 409
Interpretation by Alcide De Rizzardi, 1953

“for emptying moats”

During his apprenticeship in the Florentine building yards, Leonardo has the chance to observe many cranes, among which are those designed by Brunelleschi. He draws them in many pages of his manuscripts. These models are designed to be used in stone pits and channel digs. In the double-arm version, the movement is facilitated by the counterweight: while one arm is loaded with the recently cut mass, the other arm unloads the previous block. At this point, the platform rotates to reverse the positions of the two arms. The cranes can also be pulled on rollers for short distances.

The model is based on the drawing:

  • Manuscript B f. 49 v. (1487-1490)
    Paris, Institut de France