11 with or without its container 4 from the main track 31 to the rectilinear length 33 or conversely from this rectilinear length 33 to the main track 31 an unloading section comprising a second rectilinear track length 35 connected to one end of length 33 via a portion 36 curved at 90 u00b0 a third rectilinear track length 38 connected to the second end of the first length 33 via a second curved portion 37 a fourth rectilinear track length 40 connected to the third length by a third curved portion 39 this third length 40 extending parallel to the first length 33 and being equipped at its end with an automatic loading device above length 35 of the unloading section there is disposed a conveyor 42 adapted to mesh with the upper bosses 1 of the container c brought by the self propelled carriages 11 into the unloading area once the carriage 11 and container c have been disassembled by a rearward movement of carriage 11 container c remains suspended on conveyor 42 the latter may then have a slope so that container c can move under the effect of its own weight as far as a storage area the loading area 41 associated with length 40 of the loading section comprises two successive loading zones z l z 2 on which container c may be centered so as to be automatically assembled on carriage 11 and be locked in the way described above it can be seen that not only the loading station but also the unloading station may be formed without using complex distributors thus in the example shown in fig8 the loading station 43 comprises a distributor formed by a simple drawer 43 for bringing and.