The two main categories are general and bulk cargo. General cargo is unitized (carried in defined load units) while bulk cargo is loose (carried in any quantity).
General cargo can be sub-divided into three categories:
Also called General cargo, it is handled as separate pieces, loaded individually or in lots without being consolidated in a container. For example, wind turbine blades, large generators, pipes, bundles of steel rods, …
Cargo may be unpacked, possibly protected by a tarp, or could be in a crate or a special transport frame.
This cargo type often includes very large and heavy items and relates to the delivery of industrial or construction projects – it may then be named Project cargo.
Typically loaded by standard shore or vessel cranes or by mobile or floating cranes.
Any cargo which is rolled on or off from a vessel, concerns cargo where each pre-packaged unit is accountable it may be self-driven (cars, buses, trailer, and tractor…) onto the vessel, or may be wheeled (unaccompanied trailers, certain construction equipment…), or loaded onto a roll-trailer (container, generator, etc…) and towed onto the vessel.
Terminals will generally contain a storage or waiting area and – even if most RORO vessel have their own built-in ramps – may be equipped with a ramp to further ease the loading and offloading operations.
The growth of container shipping required creating a new general cargo category where the cargo is being carried in container load units.
Bulk cargo can be divided into two categories:
Liquid cargo transported in its free-flowing liquid form (crude oil, vegetable oil, chemicals, wine…) or in its liquid gas form (natural gas, liquid petroleum gas).
Poured in or sucked out of the hold, the tanks of liquid bulk vessels by specialized port equipment, such as articulated lines pipes which are in turn connected to storage tanks. These reservoirs can be located on the quay or further away and reached thanks to a pipeline.
Cargos such as grain, sand, gravel, iron ore, cobblestones which is homogeneous, unpacked, and transported loose in large quantities is called Dry bulk cargo.
This cargo is typically loaded by vessel or shore-cranes equipped with buckets. Offloading operations are commonly facilitated by the usage of funnels.
In more specialized terminals, conveyor belts may also be used, and storage location (such as silos for the agro-bulk dry bulk cargo) may be present.