History of the crane (machinery)

The history of the crane, a lifting machine used to move heavy materials includes its invention in Ancient Greece, through its modifications in Ancient Rome and evolution in the High Middle Ages through the Industrial Revolution.

Ancient Greece

The crane as a machine for lifting heavy loads was invented by the Ancient Greeks in the late 6th century BC.[1] The archaeological record shows that no later than c. 515 BC, distinctive cuttings for both lifting tongs and lewis irons begin to appear on stone blocks of Greek temples. Since these holes point at the use of a lifting device, and since they are to be found either above the center of gravity of the block, or in pairs equidistant from a point over the center of gravity, they are regarded by archaeologists as the positive evidence required for the existence of the crane.[1]

The introduction of the winch and pulley hoist soon led to a widespread replacement of ramps as the main means of vertical motion. For the next two hundred years, Greek building sites witnessed a sharp drop in the weights handled, as the new lifting technique made the use of several smaller stones more practical than of fewer larger ones. In contrast to the archaic period with its tendency to ever-increasing block sizes, Greek temples of the classical age like the Parthenon invariably featured stone blocks weighing less than 15–20 metric tons. Also, the practice of erecting large monolithic columns was practically abandoned in favour of using several column drums.[2]

Although the exact circumstances of the shift from the ramp to the crane technology remain unclear, it has been argued that the volatile social and political conditions of Greece were more suitable to the employment of small, professional construction teams than of large bodies of unskilled labour, making the crane more preferable to the Greek polis than the more labour-intensive ramp which had been the norm in the autocratic societies of Egypt or Assyria.[2]

The first unequivocal literary evidence for the existence of the compound pulley system appears in the Mechanical Problems (Mech. 18, 853a32-853b13) attributed to Aristotle (384–322 BC), but perhaps composed at a slightly later date. Around the same time, block sizes at Greek temples began to match their archaic predecessors again, indicating that the more sophisticated compound pulley must have found its way to Greek construction sites by then.[3]

References

  1. ^ a b Coulton 1974, p. 7
  2. ^ a b Coulton 1974, pp. 14f.
  3. ^ Coulton 1974, p. 16

Sources