Drive-In Rack is exactly what the name implies. The forklift operator, rather than driving up to the rack to store or retrieve a pallet, drives into the racking system. Drive-In rack is one type of “high-density” pallet racking system.
“High-density” racking systems, such as Drive-In rack maximize the pallet storage capacity of a warehouse space by decreasing the number of aisles needed to access the pallet loads being stored.
Drive-In does this by storing material two or more pallets deep rather than the one pallet deep configuration of selective pallet rack. The pallets sit on horizontal rails fastened to either side of two vertical uprights. The forklift drives between these vertical uprights to store or retrieve pallets.
The pallet support rails are at various heights of the upright so that pallets are stored vertically, similar to selective rack. However, the rails extend back (fastened to sets of uprights) so that pallets are also stored multiple pallets deep. For example, a system may store pallets 4 high and 12 deep for a total of 48 pallets per lane. This configuration significantly increases pallet storage density by reducing the number of forklift aisles needed to access the pallet storage space.
Although Drive-In rack maximizes pallet storage capacity, it is generally a slower process to store and retrieve pallets. The space between the vertical uprights is narrow by design necessity, so the forklift driver has to proceed cautiously so as not to damage the rack. Angle guide rails are often installed on the floor at both sides of the lane to guide the driver and prevent rack damage. Of course, the deeper the lanes, the slower the process.
Drive-In rack, because of its design, lends itself to “like” products rather than a variety of different products stored in any one lane. In the 48 pallet lane example mentioned above, you would not want to remove 47 pallets in order to retrieve the one pallet of material needed.
The configuration of Drive-In rack is consistent with a LIFO (last in, first out) inventory system, so it is not conductive to a material handling environment that requires stock to be rotated. However, stock rotation can be accomplished in a Drive-In rack system by emptying one lane completely once it is full while storing new incoming material in an adjacent lane, and continually repeating this process.