How it began
The evidence is in the stones. J. J. Coulton, writing in the Journal of Hellenic Studies in 1974, showed that cuttings made for lifting tongs and for lewis irons first appear on the blocks of Greek buildings of the late sixth century BCE. Among them are the Treasury of the Athenians and the Alkmaionid temple of Apollo at Delphi, the Old Propylaia at Athens, the Treasury of the Megarians at Olympia and the temple of Aphaia on Aigina. He concluded that the crane or hoist came into use around 515 BCE.
Before it existed
Earlier Greek builders moved stone the way the Egyptians did, with levers, ramps and massed manpower. Pulleys and cranes were unknown in Egypt, and Greek methods of quarrying and dressing stone show close borrowing from there. Pliny describes how Chersiphron raised the architraves of the temple of Artemis at Ephesos in the mid-sixth century on a temporary ramp, hauling the blocks up on rollers. Ramps set no limit on weight, and sixth century builders handled at least thirteen blocks of more than 20 tons.
How it works
Both kinds of cutting imply that the block hung from a rope. Tongs gripped holes cut in the stone, and a lewis iron locked into a socket. The cuttings sit over the center of gravity of the block or in pairs at equal distances from it, so the stone hung level. A simple pulley only changes the direction of pull and was known from an Assyrian relief of the ninth century BCE. The earliest certain evidence for compound pulleys, which multiply force, is a text of the early third century BCE from the school of Aristotle.
What changed first
Block sizes dropped at once. After about 515 BCE, through the fifth and fourth centuries, no blocks of more than 20 tons were used, and builders made a deliberate effort to hold weights down. The architraves of the Parthenon weigh about 9.5 tons each, against 41 tons at Ephesos. Coulton tied this to the limited capacity of winches and simple hoists compared with ramps.
What lasted
Coulton's explanation for the change was social. A ramp needs a large body of unskilled labor, while a hoist needs a small skilled team working over a longer time. By the end of the sixth century conditions in Greece made large gangs hard to assemble, which favored professional crews with cranes. Later cranes built on compound pulleys were described by Vitruvius and by Hero of Alexandria, and they are the basis of the standard accounts of ancient lifting.
