Utilising a revolutionary design concept first developed in the 1960's the container ship is part of a complete cargo transportation system in which road and rail transport are closely integrated.
Traditional methods of loading cargo involve loading and unloading numerous items at each stage of the journey. This is a very slow process, and turning around a general cargo ship may take up to two weeks. Using the container system, goods are loaded into containers at the factory and remain in them until they reach their destination.
The containers are large standard sized boxes constructed from steel, aluminium or more modern containers from fiberglass reinforced plastic laminated plywood. They are designed for repeated use and stacking over a period of years. Some containers open at either end for loading purposes and others open at the top.
Container ships are divided into various container sized cells and are loaded and unloaded simultaneously by giant gantry cranes. As one container is lifted into place another is unloaded. The process of loading and unloading is usually computerised allowing an exact sequence of operations cutting down the time the ship spends in port.
A conventional cargo ship may spend 75 percent of its working life in port whereas a container ship typically spends around 20 percent. This enables the container ship to make three times as many trips and carry three times as much cargo as a conventional cargo ship. This allows greater profits for the company as their fleets can be reduced by up to two thirds with no appreciable loss.
