Different Ways of Loading Cargo Onto Ships

A supertanker carries 450 times more oil than a 19th Century whaling ship.

Cargo handling in the past might be represented by a long line of men passing cargo from hand-to-hand until the cargo was deposited in the hold of a ship. In today's world, the line of men has been supplanted by high-capacity cranes and a variety of mechanical loading devices that may seem more at home in a factory, on a farm or at a filling station.

Containerized Freight

You can see containerized freight moving along any highway.

The container is a box between 26 feet and 40 feet long and no wider than a standard freight trailer, that may be loaded with boxed freight. Small boxes, crates and pallets of cargo that were once loaded into a ship's hold are now consolidated within a single large box that can be towed behind a truck or loaded onto a train before being loaded aboard ship. Freight consolidation's impact is measured in faster turnaround times at a port where a single crane lift to load one container replaces the piecemeal loading of "break bulk" freight.

Bulk Freight

The bulker's derricks allow it to unload in ports without bulk facilities.

Bulk carriers, with huge dry tanks instead of holds, are filled by systems once at home on the farm or in the factory, including pipes in which an auger turns to push pellets of iron or other ores into the hold. Mobile conveyor belts are used to load coal or other dry, loose, unpackaged cargo. Some products, such as sorbalite clay or wheat and other grains, can be blown into the tanks through pneumatic tubes connected to the ship's tanks.

Liquid Products

Tankers, carrying liquid products of all kinds, are loaded from liquid bulk facilities that transfer their products through miles of "hard piping" and hoses. Specialized handling booms bring the hoses aboard and connect to "innage" holes, the loading points on the tanker. Aboard the tanker, the person in charge of loading, usually the chief mate, controls the loading process to ensure the ship's stability. The chief mate stays in constant radio contact with the loading facility to ensure the loading process continues safely and without environmental consequences.

Offshore Loading

Crude oil travels the oceans on two classes of ships, very large crude carriers and ultra-large crude carriers. Because of their size, VLCCs and ULCCs cannot come into port in the U.S., making loading at an offshore oil terminal necessary. The ship ties up between three mooring buoys near the terminal. A loading/discharge hose is then connected to the ship and the oil is pumped, through a system of undersea pipes, to or from a storage facility on shore.

References

• South Carolina State Ports Authority: Container Port
• Duluth Seaway Port Authority: Bulk Cargo Operations
• Alyeska Pipeline: Valdez Marine Terminal
• LOOP LLC: History