Abstract: Within a vault (11) having an access aperture (12), a number of rectangular racks (1, 2) are individually and detachably mounted on an annular turntable (14) rotating in a horizontal plane. Each rack accommodates in compartments (6) of variable sizes a single row of individually accessible, superposed safe-deposit boxes (4), all the compartments of any one rack opening out on the same side of that rack. Within the turntable is a vertical hoist mechanism (7) comprising an upright (8) and a horizontal lifting arm (9) travelling along the upright. A selected rack (1a) is moved into a starting position by the turntable, seized by the lifting arm, and raised to the level of the access aperture independently of the other racks. There is no possibility of breaking through laterally from a safe-deposit box of any one rack into a safe-deposit box of another rack.