Posted on: 29 January 2020Share
Cranes are useful in so many settings and in so many ways. To call a crane an overhead crane is a matter of a technicality, a truth, and a myth all rolled into one. To explain this better, the following is provided.
Technically, All Cranes Are "Overhead" Cranes
Technically, any crane that lifts anything over your head is an "overhead" crane. All cranes lift things over people's heads; that is just what cranes do. What you want to pay attention to is the job at hand, the type of crane you need to do the job, and how the type of crane selected will complete the job. For example, an elevator crane has rigging that attaches to the side of a building like an elevator shaft and lifts things overhead via an elevator car. A boom crane has rigging that can extend several stories up and lift things overhead to a floor on a construction site where the workers are busily constructing that floor and floors above it. An industrial or factory type of crane is essentially a motorized box with a cable and single hook for lifting things overhead on one axis or two axes.
Truthfully, When You Say Overhead Crane, It Is Assumed That You Mean the Industrial Kind
A true overhead crane consists of a heavy duty steel beam on which a free-moving motorized box is attached. These cranes are completely overhead at all times. The hooks on the ends of the long cables coming from the crane boxes can lift, flip, pull, or drag anything you want, just so long as what is on the end of the hook and cable is supposed to be moved in one of four directions.
Usually, the requirement is only two directions, since the motorized box slides back and forth along a single beam. However, there are overhead cranes that can shift ninety degrees in the center of a beam to travel in a perpendicular direction to the first beam. If there are two intersecting beams like this, the motorized box can travel four directions (backward and forward along either beam in directions perpendicular to each other).
Myths about Overhead Cranes
People generally assume that you can only use these cranes inside a manufacturing or industrial plant. Not so; they have been used in warehouses, in construction sites, and even at shipyards. You can do a lot more with them than you might think.