SPACE UTILIZATION

In planning the storage facility, the spaceutilization layout includes the site space of the building, floor area, and the building "clear height." Planning the

Figure 2-1.-Typical cyclic-flow pattern.

site of the building is a job for engineers and architects. You may be involved with planning the warehouse floor area and "clear height" for maximum storage utilization. The following text describes some factors that you should know before you do the plan.

Utilization of Floor Area

The storage pattern for facilities used for pallet rack operations is designed according to the MHE that will be used to move the material. The dimensions of the aisles depend upon the size of the forklift trucks. Material handling and storage methods used to actually

Figure 2-2.-Typical straight-tine flow pattern.

move and store material are affected by some limiting factors. These factors are

l the dimension of the pallet or load to be handled,

l the dimensions of the MHE to move the pallets, and

l the spacing between support columns and overhead clearances.

In general, utilization of floor area is maximized by minimizing aisle spare. Aisle space can be minimized by using modem narrow aisle storage equipment and storing material in depth when possible. An example of depth-type storage are those materials that are inventoried in multiple pallet quantities. See figure 2-3 for an example of storing material in depth. In this example, the different categories of palletized material in each row are identified by letters.

Utilization of Building Clear Height

The term clear height is often confusing when dealing with architects or engineneers. It can mean the height from the floor to the bottom of the roof or to the bottom of the beams. In material handling, "clear height" means the height under all lighting, heating, and other overhead obstructions. Clear height is the available effective height for storage space that is below all necessary clearances. The overhead clearance required below the sprinkler system is at least 18 inches for stacks up to 15 feet. This clearance must be at least

36 inches for stacks higher than 15 feet. All overhead obstructions must be 10 inches above the highest equipment clearance level.

The utilization of clear height is affected by the stackability of the material, storage space, MHE, and

floor-load limit. When pallet racks are used to achieve storage height, the stackability of material is not critical. When using floor stacked bulk storage, the stackability and instability of material directly affect the height of storage. Using storage aids such as pallet frames will permit load stacking and provide protection to the material.

Aisles

The preplanning of the aisles in the layout must be

done before placing material in storage. Aisle layout is determined by the structure of the building, quantity, nature, and activity of the material to be stored. The aisle should be wide enough for maneuvering the type of MHE to be used. The aisle in bins and shelving areas should be wide enough for stock selector trucks.

Normally, this requires an aisle of 30 to 36 inches in width. The aisles should provide a straight, clear, and unobstructed passageway. To determine the width of the aisles, use the measurement of the turning radius of the MHE.

The working aisles are used whenever material is placed into or removed from storage. The two types of working aisles are the transportation aisles and the cross aisles. The transportation aisles run the length of the building. The cross aisles run the width of the building. Depending on the activity or operations, most warehouses require two transportation aisles. The aisles should be wide enough to permit two-way traffic for the MHE being used in the area.

Personnel aisles are those used as pedestrians routes only to provide access to doors or other areas. Having this type of aisle should be held to a minimum. Use the working aisles also as pedestrian routes if traffic and safety permits.

Figure 2-3.-Storing palletized material in depth. 2-5

Service aisles are those that permit access to stacks for inventory, inspection, or protective processing. These type of aisle requirements are normally very limited. It is not needed for warehouses that store bulk items in rows with the same number of containers in _{each pallet.} Similar items stored in rows facilitate inventory as well as issue and make service aisles unnecessary.