Cranes have been a useful construction and manufacturing tool for centuries. This simple device has gone through many changes to adapt to the needs of its users, and an electric crane is one of the more recent technological developments. These tools are smaller than enormous construction cranes and come in two distinct types that assist with small, precise jobs: the jib crane and the overhead crane. The electric crane also is renowned for being more environmentally friendly and quiet than other types of lifting devices.
All cranes use leverage and external power to lift and lower items with much more strength than humans can provide individually. This tool is believed to have been invented by the Greeks in the sixth century B.C. and utilized the same principles of a winch and pulley and long leverage boom that still are used today. Over time, a variety of sources were used to control the pulleys, from animal power to steam power, fossil fuels and, currently, electricity.
The electric jib crane encompasses the most traditional form of electric crane because of its long boom arm design. This arm usually is mounted to a wall or floor to give it the stability necessary to lift much heavier objects. Electrical motors allow the arm to move horizontally or vertically, giving it a full range of motion like a human arm. The jib crane can be programmed to perform the same function over and over again, such as in factory work, or it can be hand-controlled to perform unique tasks, such as in construction and warehouse operations.
An electric overhead crane is the most popular type of crane found in many manufacturing and organizational settings. The basic setup of this electric crane is a series of overhead metal girders that act as a track for the crane to move forward, backward and from side to side. An electric motor powers the movement along the girders as well as the wench-and-pulley system used to do the lifting. Overhead cranes are commonly found in factories that routinely require large items to be moved where other tools, such as a conveyor belt, might not be practical. Organizational industries, such as warehouses and docks, also use overhead cranes to move heavy objects and reorder them with precision.
Precision and power are two major advantages these cranes provide, but they are not the only reasons they are used. Electric motors run more quietly than fuel-powered engines, so communication is easier among workers because of the lower noise level. Electric power also is more environmentally friendly than the use of fossil fuels.
