RACK STORAGE
These are the definitions of a rack and the types of rack storage as found in NFPA 231C, Standard for Rack Storage of Materials.
Rack. Any combination of vertical, horizontal, and diagonal members that support stored materials. Some rack structures use solid shelves. Hacks may be fixed, portable, or movable. Loading may be either manual, using lift trucks, stacker cranes, or hand placement; or automatic, using machine-controlled storage and retrieval systems.
Single-row racks. Single-row racks are racks with no longitudinal flue space and having a width up to 6 ft. (1.8 m) with aisles at least 3 5 ft. (l .l m) from I other storage.
Double-row racks. Double-row racks are two single-row racks placed back to back, having a combined width up to 12 ft. (3.7 m) with aisles at least 3 5 ft. (1.1 m) on each side.
Multi row racks. Multi-row racks are racks greater than 12 ft. (3 7 m) wide or singleor double-row racks separated by aisles less than 3 5 ft. (1.1 m) wide having an overall width greater than 12 ft. (3.7 m).
Portable racks. Portable racks are racks that are not fixed in place. They can be arranged in any number of configurations.
Movable racks. Movable racks are racks on fixed rails or guides. They can be moved back and forth only in a horizontal two-dimensional plane. A moving aisle is created as abutting racks are either loaded or unloaded, then moved across the aisle to abut other racks. Rack arrangements generally result in the same protection needs as for multi-row racks.
(See complete standard for details.)
