The four-mast crane (scaffold)

It consisted of four vertical beams which were connected to horizontal (transverse or cross beams and oblique security struts) (“antirides”) ones. The load was suspended via block and tackle (“polyspasto”) from the inside of the machine. With the combination of many four-mast cranes, the “scaffolds” were created which had, on their vertex (on rollers), manually operated winches for load elevation.



SOURCES: Vitrouvius, On architecture, X, Heron of Alexandria, Mechanics, Pappos of Alexandria, Mechanics.