Port cranes are heavy lifting equipment specially designed for loading and unloading cargo (especially containers, bulk cargo and general cargo) in ports, docks and shipyards. They are the core and "muscle" of the efficient operation of modern ports, responsible for the fast and safe handling of cargo between ships and land transport vehicles (such as trucks, trains) or yards.

Here are some key features and common types:

Core functions:

Ship loading and unloading: Lifting cargo from the cabin or deck and placing it on the dock or transport vehicle, or lifting cargo from the dock to the ship.
Yard operation: Stacking and moving containers or other cargo in the yard.
Transshipment: Transferring cargo between ships, trucks and trains.

Main features:
High lifting capacity: Can lift tens or even hundreds of tons of heavy objects (such as fully loaded containers).
Large working range/span: With a long arm or span, it can cover the hatches of large ships and wide yard areas.
High lifting height: Need to cross the side of the ship, reach the bottom of the cabin or stack multiple layers of containers.
Efficiency: The design goal is to achieve the fastest possible loading and unloading speed (such as container cranes handling dozens of boxes per hour).
Stability and safety: The structure is sturdy and equipped with multiple safety devices (overload protection, windproof anchoring, limit switches, etc.) to cope with the offshore environment (wind, waves) and heavy load challenges.
Specialization: There are specially designed cranes for specific cargo types (containers, bulk cargo, heavy pieces).
Intelligence: Modern cranes are increasingly using technologies such as automated control, remote operation, intelligent anti-sway, and positioning systems.

The most common types of cranes in ports:

Gantry cranes:

There is a large gantry at the bottom, and trains or cars can pass under the gantry.
Rotating superstructure with variable-length boom.
It has a wide range of uses and can load and unload containers, general cargo, and bulk cargo (with grab buckets).
It has good flexibility and can be moved in the front and rear yards of the terminal.

Shore container crane:

Also called container bridge crane and quay crane.
The most core and conspicuous equipment of the port container terminal.
The tall steel structure gantry spans the rails on the dock shore.
There are main beams (front beam and rear beam) that can pitch and fall and a lifting trolley that can run forward and backward on the main beam.
Container spreaders (such as telescopic spreaders) are suspended under the trolley.
Specially designed for efficient loading and unloading of container ships, directly from ship to shore or shore to ship.

Rubber-tyred container gantry crane:

Also called yard crane, tire crane.
Mainly used for container handling, stacking and loading and unloading trucks/chassis vehicles in container yards.
It consists of an elevated gantry structure and a lifting trolley that can run on its track beam. The entire crane is supported by tires and can move on its own in the yard.
It is flexible and maneuverable and is the main force in yard operations.

Rail-mounted container gantry crane:

Similar to the tire-type yard crane, but runs on fixed tracks.
Usually has a larger span, a higher number of stacking layers, more stable operation, and better energy saving effect.
Commonly used in rear yards or railway operation areas.

Other related types:

Reach stacker: A mobile crane with a spreader, mainly used for short-distance handling and stacking/loading and unloading trucks within the container yard, with high flexibility.
Grab crane: Usually based on a portal crane or a fixed crane, equipped with a grab bucket, used for loading and unloading bulk cargo (such as coal, ore, grain).
Floating crane: A crane installed on a pontoon or a special hull, used for loading and unloading without fixed dock facilities, lifting of large items at sea, rescue and salvage, etc.

In summary:

Port cranes are large, efficient and specialized loading and unloading equipment that are indispensable in the port logistics system. They are like the "giant arm" of the port, shouldering the key task of connecting cargo from sea transportation to the land transportation network, and their efficiency and reliability directly affect the throughput capacity and competitiveness of the entire port. The most common representatives are the huge container bridge cranes standing on the shore and the yard bridges shuttling in the yard.