EXHIBITS > The elevating mechanisms of the ancient Greeks >
Heron's two-mast crane
It was constituted by two large (slightly inclined by vertical) joists and one horizontal in the form of Π. The elevation was achieved with the use of "pentaspaston" with three "wheels" in the (above) constant "pulley" and two in the (below) free one. The machine was usually placed on rollers for its horizontal shifting. The traction force of the rope for the elevation of the load was emanated by animals or by a powerful manually operated ground winch.
SOURCES: "Heron of Alexandria, Mechanics", "Pappos of Alexandria, Mechanics"