An Examination of Tower Cranes

Tower CranesIf you ever visit the downtowns of big cities like Boston, Providence or Hartford, you’re apt to see tower cranes dotting the urban skyline. Tower cranes are used to move heavy items around construction sites, so of course they’re used to construct skyscrapers in cities.

Tower cranes, no matter how tall or strong, all have the same main parts including the base, the slewing unit (which allows the crane to rotate), and the jib, aka the “working arm,” which carries the load.

Tower Crane Are Sturdy

Did you ever wonder why cranes don’t fall over? It’s thanks to their concrete base which gives them amazing stability while preventing bending. If you ever get a chance, look and see how tower cranes are literally anchored and bolted to the ground, too. Tower cranes also utilize massive concrete ballast blocks. These hang from the jib arm and act as counterweights.

Tower Cranes As We Know Them Originated in Europe

Tower cranes as we know them pretty much originated in Europe. Modern tower cranes came of age in the 1950s thanks to post-war rebuilding efforts in countries like Germany. Older cranes were hydraulically powered, but then manufacturers made the switch to electric in the 1970s. Did you know the average tower crane uses about 800 amps? That’s a lot of power.

Tower Cranes Are Vital to Jobsites

How Tower Cranes WorkSo what do tower cranes do for job sites? Well, they lift and set steel on different floor levels. They help pour concrete or set precast panels in place. And they can be used to place permanent electrical and mechanical systems for their final installation(s). Thanks to today’s tower cranes, very tall buildings can be constructed in very tight (dense) city spaces. Tower cranes allow construction crews to work quickly, efficiently and affordably.

Ancient Greeks Made the First Cranes

If you were to travel back in time, you might see the first ever human-made crane around 500 BC. Built by the Ancient Greeks, it was made of wood and powered by humans and animals in order to lift heavy objects up and construct buildings like the Parthenon in Greece. In the Middle Ages, the “jib” came into being, allowing the crane’s arm to move horizontally. Around this time, cranes were often used to unload cargo from sailing ships in harbors around the world. After the steam engine was developed, that technology was added in order to power cranes.

More than 200K Tower Cranes Worldwide

Today there are some 200,000 cranes in the world, with about 125,000 used in construction and the rest used in general/maritime industries. Cities known for their tall buildings, like Hong Kong and Dubai, have tower cranes to thank for their impressive skylines.

Tower Cranes Are Among the Tallest Options

While there are many types of cranes, tower cranes are the tallest standing of cranes. Generally used to construct high-rise buildings, tower cranes are usually transported to job sites and then assembled using a mobile crane. Styles of tower cranes include hammerhead, flat-top, self-erecting or luffing jib configurations, with a 100 to 800 ton meter rating.

Do you need a crane in the New England area? Astro Crane can help! Call 978-429-8666 to ask about renting a crane.