Often used in bulk cargo loading operations, gantry cranes are bridge cranes mounted on legs that run along a set of fixed rails or similar track. The term is also applied to portable bridge cranes that are set on wheels or other rollers. A bridge crane involves a hoisting apparatus mounted on a crossbar or other bridge-like structure suspended between at least two legs over the material to be hoisted.
Because of their inherently sturdy design, gantry cranes are employed in a wide range of heavy transport applications, from lifting and moving locomotives for repair and maintenance to the unloading of multi-ton shipping cargo. In fact, some gantry cranes have lifting capacities that rate over 65 tons; these devices are typically used for loading and unloading massive international shipping containers. Even certain portable models can lift 5-ton loads, which makes them well suited to small material handling tasks, as well as on-location construction and warehousing applications.
In a large industrial gantry crane, also known as a dockside and container crane, the operator sits in a compartment right above the hoisting area. Smaller gantry cranes are often operated from side controls or through a remote system. The most basic types involve a manual hoisting system, such as a specialized pulley or similar device, which requires the operator to perform the necessary lifting work.
Gantry cranes are available in light-weight aluminum designs, as well as more sturdy materials, such as steel. Portable aluminum cranes provide an easily assembled and disassembled mobile hoisting system, which facilitates transport between job sites. Fixed gantry cranes tend to have much higher lifting capacities, and are often customized to facility or ship operations. Given the system design, large gantry cranes can support crossbeam tracks spanning more than 100-feet.