Cranes are a feature of most cities, decorating the landscape and horizon in larger or smaller numbers. They signal the rise of yet another building and, usually, the demise of the building—or buildings—that previously occupied that location. From man’s destruction arises yet another of man’s temporary creations.
Without cranes there would be no magnificent cathedrals, temples or mosques. There would be no skyscrapers. But there were the pyramids and other ancient buildings all constructed without the use of the technology represented by the cranes.
The Greeks are generally thought to have first invented the crane, powered by men or beasts. Later technologies, like the human powered treadmill, allowed greater loads to be manipulated and greater heights to be traversed. Over time new designs arose along with new uses: harbour cranes, mobile cranes on land and water, telescopic cranes, sidelift cranes; an endless variety. Steel replaced wood as the fabrication medium allowing even more power for lifting to ever greater heights.
So now cranes are just another instrument in man’s ever enlarging toolbox, another outcome of man’s ingenuity and his desire to make light of heavy work, to make the impossible (heights) possible. Cranes now blend into our cityscape, supplementing and even complementing those other constructions with which we adorn our urban environment.
Yet, despite their proliferation, their imposing sight, their grandness—or perhaps because of it—we often fail to notice cranes altogether and remain oblivious to the simplicity that belies the modern form of these marvels of engineering. At its simplest a crane is a raised pulley (or smooth surface) over which passes a cable of some material to assist in raising or lowering a mass. So much technology, so much understanding of physics, so much engineering underpinning such a simple concept.
Look around you. Look for the technology that underpins our modern lives, that gives us what we have. Look for the physics at play in the world, look for and appreciate the engineering, the innovation that gives us our way of life. And look for cranes. You can find them in the most unexpected of places.
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