Materials storage aisles

Protection of facilities that are exposed to a fire hazard from an outdoor storage area is preferably achieved passively by adequate separation distance to the potentially exposed facilities. When the quantity of stored material is large, it should be separated into smaller groups or piles with adequate aisle space maintained to prevent uncontrolled fire spread within the defined storage area. An often used spacing guide for stacked or piled materials is aisle width should equal stack height. 

There shall be at least one clear aisle at least 3 feet (0.9144 meters) wide in every flammable and combustible material storage room. No container should be more than 12 feet (3.66 meters) Irom an aisle. Containers of 30 gallons (113.5 liters) capacity or larger must not be stacked more than one layer high. 

The inventoiy system needed is FIFO, which is desirable when inventories are subject to obsolescence or deterioration or when they consist of raw materials that fluc tuate widely in value. The capital investment for a typical aisle-rack storage system having a 5000-paUet capacity (I deep) is 6.5 per stored pallet (this does not include hft-truck investment). 

Housekeeping and storage of materials are orderly. Heavy and bulky objects well stored out of aisles, etc. 

Storage rooms for flammable and combustible materials (29 CFR 1910.106). Mark an aisle at least 3 ft wide in every inside storage room. 

There must be enough aisle space between racks and items stored openly. The aisles should allow vehicles to place materials on racks or remove them safely. Because aisle width is an important economic consideration in storage facilities, special vehicles can minimize aisle width requirements. 

Overpmduction At Station C, the machinery processes parts faster than can be handled by the remainder of the production line. Thus, materials in progress get stacked in aisles until they are transferred to a storage area. Having excess materials in process is wasteful. An additional result is overly stressful manual material handling and the ergonomic risks that implies. 

Transportation Station D represents the wastes deriving from the additional storage space and material handling needed because of overproduction at Station C. The storage configuration is not conducive to efficiency. Aisles are narrow. Powered vehicles have collided, have struck workers, and goods have been damaged. 

Pallet Frames. Pallet frames (Fig. 4.51) are useful where materials lack the rigidity or stability to be stacked on the floor and where there are a large number of storage units in inventory. The pallet frame attaches to the pallet and extends above the material. The frame acts as a structure on which another pallet is stacked. Pallets so stacked are often placed several stacks deep and thus conserve floor space as compared with pallet racks which require aisle access. The frames are removable for pallet loads not requiring support. 

Two-Deep Pallet Racks. These racks (Fig. 4.52) are similar in design to the one-deep pallet rack except that two pallets, one behind the other, are stored in each position. Two-deep racks are used when there is insufficient floor space to accommodate the required number of one-deep racks. Two one-deep racks are normally placed side by side and require aisle access from each side of the two-rack combination. The two-deep rack requires access from only one side but stores the same amount of material as the two one-deep racks placed side by side. The ratio of aisle to storage is thus reduced by using two-deep racks. 

Some of the important factors affecting the size (sq ft) and capacity of a warehouse are customer service levels, size of markets served, number of products, bulkiness of individual products, material handling systems, and the pattern of demand. Materials handling decisions include space-occupied and efficiency, economy of scale, aisle requirements, and the types of storage racks and shelves used. 

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