Gantry cranes

Gantry cranes are a type of crane built atop a gantry, which is a structure used to straddle an object or workspace. Gantry cranes for marine application are imposing, multi-story structures prominent at most container terminals, used to load intermodal containers on and off container ships. They can range from these enormous "full" gantry cranes, capable of lifting some of the heaviest loads in the world, to small shop cranes, used for tasks such as lifting automobile engines out of vehicles.

They are also called portal cranes, the "portal" being the empty space straddled by the gantry. The terms gantry crane and overhead crane (or bridge crane) are often used interchangeably, as both types of crane straddle their workload. The usual distinction drawn between the two is that with gantry cranes, the entire structure (including gantry) is usually wheeled (often on rails). By contrast, the supporting structure of an overhead crane is fixed in location, often in the form of the walls or ceiling of a building, to which is attached a movable hoist running overhead along a rail or beam (which may itself move). Further confusing the issue is that gantry cranes may also incorporate a movable beam-mounted hoist in addition to the entire structure being wheeled, and some overhead cranes are suspended from a freestanding gantry.

Ship-to-shore gantry cranes are some of the largest examples of gantry cranes in the world and serve the special purpose of moving shipping containers from container ships to berths for unloading and from berths to container ships for loading. They operate along two rails (waterside and landside designations) spaced based on the size of crane to be used.

Lateral movement system:

Vertical frame and braces:

Crane boom:

Hook:

Operating cabin:

Storage Equipment:

Ship-to-shore gantry cranes are often used in pairs or teams of cranes in order to minimize the time required to load and unload vessels. As container ship sizes and widths have increased throughout the 20th Century, ship-to-shore gantry cranes and the implementation of ship-to-shore gantry cranes has become more unique in order to effectively load and unload vessels while maximizing profitability and minimizing time in port. One example are systems where specialized berths built that accommodate one vessel at a time with ship-to-shore gantry cranes on both sides of the vessel. This allows for more cranes and double the workspace under the cranes to be used for transporting cargo off dock.

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