An Overhead Crane is a term that describes many different types of lifting equipment. You may be referring to a simple gantry crane fitted with a manual chain hoist and trolley. Or you might mean a high capacity portal crane, such as those used in docks and ports to load and off load container ships.
But every Overhead Crane is defined by same characteristic of lifting and moving a load using the most direct route. And that means lifting the loads over obstacles, allowing goods to be transported from A to B more efficiently.
Overhead Cranes can be found in many different environments and industries, but they are especially common in factories. The exact type used will depend on the product, working environment and duty cycle.
Structure of an Overhead Crane
The structure of an Overhead Crane will largely depend on the type of crane being used and the application it is being used for. A small jib crane will not look the same as a high capacity gantry crane. As an example, here is what you would expect of a typical Overhead Travelling Crane (OHTC):
• Bridge. The main travelling structure of the crane. The bridge consists of two end carriages and single or double girder depending on the hoist type being used.
• Gantry. The steelwork structure that supports the hoist, and beams, this can be free standing, or tied back to the building structure for additional lateral support.
• Rail. A solid bar welded to the gantry beams. This is what the end carriages run on.
• The Crab (A.K.A wire rope hoist). The part that physically lifts the load.
The Overhead Crane structure is fitted with a conductor system – the crane’s power supply. This once would have been a bare copper wire feed, but better safety standards mean these are less common. Most modern cranes are fitted with an insulated 4 bar conductor system, including an “earth” wire in case of electrical failures.
Controlling an Overhead Crane
An Overhead Crane can be cab operated, where a crane driver controls all movements of the crane by operating above the load being moved.
It is more common to find Overhead Cranes operated by radio remote controls or travelling pendants. These allow operators to stand at a safe distance from the load while still having a clear view of it. This gives the operator greater control over the load and makes the lifting process easier and safer.
This is just some basic information about Overhead Cranes – visit our Gantry Crane page for more specific information. Or contact us if you have any questions about buying the right Overhead Crane for your job.