1) Rotary rack
A rotary rack is a special variation of a horizontal carousel. In this case each vertical level or storage location is mechanically independent of the location above or beneath it. Each level in turn is driven by a separate and independent drive. Therefore, simultaneous, independent rotation of each level is possible (in any direction). Although replenishment and picking can be accomplished manually, most rotary racks incorporate automatic load inserters and extractors. See also Horizontal Carousels and/or AS/RS .