Abstract: The installation is of the type comprising a warehouse providing rows and columns of container-receiving cells opening at one end into a passageway accommodating a horizontally and vertically displaceable loading- and unloading unit. The floor section of each cell comprises a pair of longitudinal rails (4) inclined towards the passageway at a slope of 2-4%. The container (C) is handled by devices engaging its four lower corner blocks (18) so as to minimize the effects of stresses on the container structure during handling and storage. One end of the container is deposited onto a trolly (31) freely rolling on the rails. The other end is manoeuvred by a power-actuated carriage (14) rolling on an elevator platform (5) and is deposited onto supports (30) projecting upwardly from the lower end portions of the rails. (FIG. 4).