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What is an Overhead Crane?

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  • Written By: Mary McMahon
  • Edited By: O. Wallace
  • Last Modified Date: 20 October 2018
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An overhead crane is a crane which is permanently fixed in place overhead for the purpose of manipulating classically large and heavy objects which cannot be moved easily by hand. Steel mills usually have overhead cranes to handle the steel as it is fabricated into parts, and these cranes are also used at ports all over the world, to bring objects on and off ships. These cranes tend to be quite large, very expensive, and capable of moving huge volumes of material.

The construction of an overhead crane relies on a rail or beam which is permanently fixed in place on a support structure. This can be accomplished by building a crane right into a structure, or by constructing a platform which holds the beam in place. Some manufacturers also make mobile overhead cranes which are pulled by large vehicles, allowing for more flexibility.

On this type of crane, the mechanism which operates the crane is mounted on a trolley which runs along the rail. People can raise and lower items by running cable or rope through the trolley-mounted mechanism, and objects can be moved horizontally along the rail. Unlike more flexible jib cranes, which have swinging booms to allow people to move objects in multiple directions, an overhead crane only goes back and forth.

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This back and forth motion is usually all that is needed. On a container ship, for example, the ship can be positioned near the crane, and the operator can send the mechanism back and forth along the trolley to shuttle goods from the ship to a flatbed truck or train, or the other way around. By being fixed in place, the crane is much more stable, and capable of carrying very heavy loads, a distinct advantage when handling the heavy weights involved in shipping, steel working, and other heavy industries.

As a design concept, the overhead crane dates to the 1870s, when several people developed versions of this crane design for an assortment of applications. In addition to the huge scale versions used in industrial applications, smaller overhead crane styles can also be found for use in home workshops and small businesses where a crane might be useful. A woodworker, for example, might appreciate the availability of an overhead crane to haul lumber, finished projects, and heavy tools between a workshop and a loading area. Enterprising craftspeople can build their own, assuming that they have a workshop or structure with exposed beams upon which rails can be mounted.

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Charred
Post 4

@nony - I think that overhead crane equipment is used to move large airplane equipment or even huge, industrial fans. I think it’s the safest approach and one that will get the most precise movements, getting as close to the target platform as possible.

nony
Post 3

@hamje32 - Just don’t stand under a load and you’ll be fine. Most operators I’ve seen are usually in separate booths as they pull on the motorized cable that is used to lower and hoist the crane. I don’t think they are in any imminent danger as long as they keep a safe distance.

hamje32
Post 2

@David09 - I am not aware of the particular incident you refer to but I don’t doubt that accidents can happen with any type of equipment.

However, I’d rather work with an overhead crane than a jib crane. I’ve seen jib cranes and they are just long, swinging arms. I’d sooner think that such a crane could be toppled over than an overhead crane could.

With an overhead crane at least you have supports to keep the machine in place. All it has to do is move back and forth.

David09
Post 1

While the overhead crane system is capable of carrying heavy loads, it also makes it more dangerous too. I heard of one such crane in the Netherlands that fell as it tried to carry an object weighing nearly 100 tons.

I don’t know the cause of the failure but I would think that workers would have to practice extreme safety measures while working around such systems.

I’d guess that you’d need to have an overhead crane inspection on a very regular basis to make sure that it’s operating within acceptable specifications.

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