It goes without saying that properly functioning transport, especially from a cost and organizational point of view, contributes to cost reduction and improves the functioning of the economy as a whole. In the short term, this becomes possible through the introduction of minor improvements or the use of learning effects. In the long term, however, we are dealing with quite significant technical, technological, and organizational changes, i.e., technical progress, the tangible result of which are new design solutions introduced into means of transport. It must be remembered, however, that the application of new technologies generally contributes to an increase in weight, or at best leaves it at an unchanged level, as well as the price of purchased cars or wagons… Nevertheless, on the other hand, it also results in extending their lifespan and a relative reduction in operating costs, as well as shortening the time of moving goods from the point of dispatch to the point of receipt.
Technical progress in transport has been taking place de facto since the dawn of time. However, its significant acceleration occurred only in the 19th century. It was then that inventions were commercialized that greatly improved and lowered the cost of transport. First and foremost, one should mention: railways, steamships, and – at the end of that century – internal combustion engines. Initially, the latter were used to power wheeled vehicles, giving rise to cars and thus the turbulent development of the automotive industry from the beginning of the 20th century. Later, they found their way into airplanes, ships, locomotives… Considering the issue of increasing transport efficiency from the perspective of introducing standardized loading units, which is the subject of this article, it should be stated that a significant breakthrough in this field actually took place only during World War II and in the following years.
First, air cargo containers became popular on a relatively mass scale. Later, which is associated with a real breakthrough in modularization, containers were introduced. These are usually closed loading units, although there are also open-top ones (discussed below), which provide the opportunity to transport the cargo inside them without the need to unload these goods when changing the means of transport within one branch or changing from one branch to another. Despite their undeniable advantages, including mainly increased flexibility and often faster transport services, containers are not without drawbacks. The most serious of these include the need to use transshipment equipment in the form of gantry cranes, cranes, forklifts, so-called reach stackers, or mounting on vehicles, which negatively affects their load capacity, hook or gate loading devices, or cranes. Certain disadvantages of containers in terms of ease of loading/unloading were eliminated by swap bodies. They are equipped with folding support legs, as a result of which they do not require the use of external loading devices or “hooks”, “gates”, and cranes installed on trucks. Although, on the other hand, the best vehicles for handling them are trucks and trailers with full air suspension (with mixed mechanical-pneumatic suspension, full mechanical, or insufficient air suspension travel, solutions with pneumatic jacks must be used, replacing or supplementing, when the need arises, the vehicle’s air suspension). Swap bodies are used mainly in road and road-rail transport, while containers are used in sea-rail/road transport as well as rail-road and road transport (air containers have been omitted here).