|Internationally, a large number of special containers has been developed; this makes it difficult, however, to build up container lines which are capable, for example, of carrying predominantly industrial products on the outward leg and agricultural products on the homeward journey. This problem is referred to as a trade imbalance. Unbroken transport chains require an optimum compromise to be achieved between the transport requirements placed on the container type by a cargo, on the one hand, and the adaptation of the cargo to a small variety of universally applicable container types, on the other. However, investigations into losses have shown that cargoes are not always fit for container transport when packed into the container. "Fit for container transport" means the demands a cargo places on the storage climate conditions in the container.
Moisture damage caused by condensation water has been noted principally in hygroscopic goods, on the container walls or on the goods themselves, for example in jute bales traveling from Chittagong to Bremen, whilst wetting damage has been noted on Indian craft items from Bombay, also in green coffee beans, raw cocoa, millet, dried fruit, sago, pepper, milk powder, fleeces, textiles and goods at risk of corrosion, such as preserved foods, steel and steel products.
The transport requirements of goods with regard to storage climate conditions in the container are largely determined by their water content and their resulting interaction with the humidity and temperature conditions of the ambient medium as well as by their biotic activity, these being the determining factors in allocation to the most suitable container type.
The following distinctions are drawn:
From the water content class, together with the biotic activity of the cargo, it is possible to deduce the different storage climate conditions requirements which are of relevance to the question of container transport of the products and the selection of the container type.