The boom works a bit like an off-center see-saw with its fulcrum (pivot) much closer to oneĮnd than the other, so giving huge leverage. Hoisting rope usually wraps around multiple rope-guiding wheels or blocks called In scientific terms, a crane is a complex machine made up ofĪt the heart of a crane are two simple machines: a pulley (the Of the boom by raising, lowering, or rotating ('slewing') it The load almost anywhere inside a sphere with a radius the length

Through 360 degrees (some rotate less, some more), you can usually position Wheels and tracks on a moving one, or both). Three essential parts are a hoist (a length of cable or 'wire rope'Īnd a winding drum), a boom (a long arm that can pivot up andĭown to maneuver the load), and some means of moving the load aroundĪs it dangles from the boom (maybe a turntable on a static crane, ('picks') heavy objects and moves ('sets') them, often with They can be built to heights of up to 80m (260 ft).Ī crane (sometimes referred to as 'iron') is a machine that lifts Cranes like this have a typical jib length of 30–50m (100–160 ft) and can lift up to 1.7 tonnes (1.9 tons) operating at their maximum reach (radius). Photo: Two 'luffing' tower cranes with their heads in the clouds. Or topples over? Let's take a closer look at the wonderful world of Rather than another? How much can a crane lift before it buckles Why are there so many different crane types? Why would you choose one Levers working together-but it still leaves plenty of interesting questions. Science behind cranes is easy to understand-they're essentially pulleys and Or gleaming football stadium could be built today without the graceful aerial ballet of the crane. But where the wonders of the modern world are concerned, we do: no soaring skyscraper We stillĭon't know precisely how ancient structures like the Pyramids were That hauled heavy materials off the ground and into new positions. Monuments to human engineering, have in common? All were built using What do these breathtaking structures, these magical Stonehenge, the Pyramids, the Empire State Building, the Burj

Six cranes