The maritime transport of many goods is assured by means of so-called container ships which can transport standardized containers which are stacked on one another on the ship.
This method of transport makes it possible in particular to reduce the costs significantly: since the containers have standardized dimensions, they can be placed on top of one another such as to form a compact assembly.
These standardized containers which are parallelepiped comprise on each of their upper tops a hooking base, which makes it possible to manoeuver them on a loading terminal using standardized hoisting and handling means.
These hoisting means, of the crane type or the like, comprise a mobile ceiling unit equipped with four hooking units, each of which is engaged in a corresponding hooking base of the container in order to grasp the container then handle it.
In addition, a container of this type also comprises on each top of its lower surface a hooking base which can be rendered integral with a hooking base of an upper surface of a container on which it is placed. One base is rendered integral with another by means of a removable lock. The containers are thus stacked whilst being attached to one another, which makes it possible to assure that they are transported in satisfactory conditions of safety, and for a significantly reduced cost.
When the goods to be transported have a height which is greater than that of a container, it is possible to secure these goods to a platform in order to load this platform on the ship by placing it on a container to which it is then attached.
Specifically, a platform of this type has a rectangular form with the same dimensions as a container in plan view, and it is equipped at the tops of its upper surface and of its lower surface with hooking bases of the same type as those which equip the containers. A platform of this type can thus be handled like a container, i.e. by using hoisting and handling means of the same type as those used for the containers.
Thus, a platform of this type makes it possible to transport on a container ship goods which are too wide, too long or too high to be accommodated in a container.
However, when the goods to be transported are both wider and longer than the platform, it is no longer possible to use a platform of this type, since the hooking units of the tops of its upper surface are no longer accessible by the hoisting means once these goods have been secured to the platform.
Specifically, it is thus not possible to handle a platform of this type if it is supporting goods which are both too wide and too long.
In practice, goods of this type must therefore form the basis of so-called oversized transport, by being stowed for example in the hold of a cargo ship, which is detrimental with reference to both the volume which is actually monopolized in the cargo ship, and the handling cost.