The first phase of containerization primarily related to industrial products, machinery, preserved foods, chemical products etc., to which no particularly stringent cargo care requirements, other than cargo securing, applied even when conventionally carried. Container services thus developed rapidly between highly developed regions, such as Europe, North America and the Far East, whose products were particularly suitable for containerization.
The second phase of containerization then extended to include products for which standard containers did not provide ideal conditions, so resulting in further rationalization by the development of special containers, such as the bulk container, refrigerated container and tank container, some of which were devoted to a single product.
During this phase, however, efforts were also made to include products requiring cargo care, e.g. active ventilation, during maritime transport on conventional general cargo ships. The next target was to include the large group of hygroscopic goods, i.e. goods exhibiting an interaction between water content and relative humidity.
This third phase of containerization was necessary in order to allow the carriage of sufficient quantities of containerized goods in both directions on certain routes and to increase the overall volume of containerized transport. High levels of containerization made it necessary to develop methods which enable the widest possible range of products to be carried using containers.
When the container transport system was being designed and rolled out, the initial assumption was that using containers would substantially simplify or completely solve many problems relating to caring for, packaging and maintaining the quality of cargoes during maritime transport. It was soon obvious, however, that simply putting the goods inside the container was not enough, that in addition to simplifying matters new problems arose in terms of maintaining quality, e.g. avoiding corrosion of metal parts and that packaging, instead of becoming superfluous, had to provide new protective functions.
These issues can be addressed in three ways:
- the development of special containers in order to adapt them to the requirements of the goods
- increasing the "fitness for container transport" of the goods by additional treatment (e.g. drying, preservation) or by suitable packaging
- providing appropriate cargo care for containers carrying critical products by selecting a suitable type of container and stowage space, stuffing the cargo properly and using the ship's ventilation system. For example, coffee has been transported in ro/ro ships from West Africa on flatracks ventilated with the ship's ventilation system.
The primary aim in developing new structural solutions, such as bulk containers, open-top containers, open-sided container or flatracks, was to minimize transport costs, e.g. loading and unloading costs and the use of container services.
These new container types do, however, result in modified storage and stowage conditions, as the climatic conditions to which a product is exposed in a closed standard container are completely different from those on a flatrack.
In order to extend the range of goods which can be transported in containers, special containers were developed with the emphasis on maintaining cargo quality, e.g. the thermally insulated container which has thermal insulation to provide protection from major temperature fluctuations and, by connection to a refrigeration unit, can become a refrigerated container. Passively and actively ventilated containers were developed to allow the air exchange required for carrying certain sensitive groups of products.
The costs of using specialized containers are high, so their use is only justified if they are filled with products which make use of these particular advantages of the special container. There are relatively tight limits on how far a container can be adapted to a particular product, in that each adaptation to one group of products generally excludes or at least restricts the carriage of other groups of products. For example, while the open container can indeed be more easily loaded with heavy cargo (machinery) than can the closed container, the open container cannot be loaded on the return voyage with goods, such as those packaged in bags and cartons, which require protection from environmental conditions. Products which are more advantageously transported in special containers are, however, not always available in identical quantities in both directions. Carrying empty containers further increases the cost of transport in special containers. It is consequently not possible to keep on developing new kinds of special containers as each kind requires a certain volume of its specialty cargo.
This explains the great importance of modifying certain cargo properties in order to make the cargo suitable for carriage in a standard container or "fit for container transport". "Fitness for container transport" generally assumes carriage in a closed standard container.
From the standpoint of the product, transport in a container amounts to storage in a more or less closed space with exposure to the cryptoclimate prevailing in this space. A product which is "fit for container transport" must be able to withstand this cryptoclimate without being impaired in quality. If it is possible to adjust the state of the product such that transport in a standard container is possible, then this is an economically sensible solution for the transport of this product.
