A gantry is a structure that is built over a work space or object and usually provides some functional benefit to the area of operations. A gantry crane is a mechanism capable of lifting heavy objects and built atop a gantry structure (estructura portico).
This arrangement (disposición) is sometimes called a bridge crane, actually the two terms can be used interchangeably as both the gantry crane and the bridge crane straddle their work area in the same way. A gantry crane is more specific and refers to the arrangement in which the entire structure can be wheeled about, most often on a set of tracks.
This is an very versatile arrangement. Gantry cranes are by far the most powerful class of cranes, delivering high lifting capacity for a small amount of space. This makes them available on just about every scale from the smaller workstation types to the mammoth gantry cranes at work in shipyards and the world’s busiest ports capable of lifting over 10,000 metric tonnes and more.
Following is an overview of common gantry cranes for a comparison of their lifting capacities.
The Ship to Shore Rail Mounted Gantry crane
The ship to shore rail mounted gantry crane represents the strongest cranes in the world. These are mounted on specialized rail systems that allow the crane to transport containers, goods and even the entire engine of a freighter ship to and from the ships docked at the quays.
These gantry cranes don’t require the use of counterweights and are built on structures capable of bearing the torque generated by massive loads. This kind of container crane in Ellsen Group is able to lift loads of 50 tons.
Workstation Gantry Cranes
At the other end of the spectrum are the practical workstation cranes that are common in factories, mechanic shops and even parcel service locations. An aluminium adjustable type gantry crane may have a workload from half a ton to three tons, the sturdier steel adjustable type gantry cranes may lift anywhere from 1 ton to 20 tons.
Sometimes these are set on tracks that run the length of the work station, but others can be suspended from an L-beam or any other convenient shape to provide a good range of access to the entire work area.
Rubber Tyred Gantry Cranes
There are gantry cranes of all sizes that feature wheels and are free to move around an area of operations without the need of rails. Rubber tyred gantry cranes are commonly used in container terminals as they can conveniently navigate their environment and straddle roads, rails and even ships when moving containers from place to place.