According to the basic rule that governs the assembly of vessels, the ships that make up these formations must be grouped in a way that reduces water resistance to a minimum. Moreover, the barges have to be arranged slightly out of line towards the rear in order to minimise the resistance exerted by the bow wave.
If the required technical equipment is available, the units of the convoy are coupled by means of flexible joints rather than rigidly, which permits a guided articulation of the convoy to better pass tight-radius curves. The bow-thrusters system can further enhance the barge's manoeuvrability. In addition, passive rudders are used to increase the directional stability of the entire convoy.
The arrangement of the barges within the convoy depends on the moving direction, either upstream or downstream. When travelling upstream, the convoy's cross-section with the current must be as small as possible in order to minimise fuel consumption. For this purpose, the barges are arranged one after the other in the shape of a cigar or an asparagus. Downstream the barges navigate side by side to improve manoeuvrability and, specifically, to facilitate stopping.
The maximum number of barges allowed in a convoy varies with the different sections of the Danube. In case of normal water conditions, a convoy with up to four barges can navigate the Danube trouble-free between the port of Passau in Germany and the Hungarian-Slovakian border. In the river's lower reaches, however, navigation is possible for convoys with up to 16 barges.