Drive-in racking offers the highest possible densities of pallet storage, with the lowest selectivity. Consequently, it is ideal for fast moving product which moves on a “pallet-in pallet-out basis.”
Drive-in racking is a series of tunnels with rails on either side to hold the pallet. Lift trucks can drive into any given tunnel to retrieve or put away pallets.
- High density racking system, with virtually unlimited depth.
- No specialized fork lift trucks needed.
- Racking is less expensive than dynamic storage solutions (pushback / pallet flow).
- Level storage medium – no concerns about height restrictions as with sloping systems.
- LIFO – if stock rotation is an issue, you need to ensure that tunnels are being fully emptied before replenishing.
- Significant reduction in pick slots, as there are fewer aisles and each tunnel can store only a single SKU, from floor to ceiling- so e.g. in a 4 level system, there are 4 times fewer pick slots on any aisle vs. other systems. Plus, there are added slots lost vs. selective, since there are fewer aisles in a given floor area.
- Typically, observed capacity utilization is lower than for other systems, around 60%-70% is not uncommon.
- Drive-in systems have more “sway” or lateral movement than other systems since there are no beams or cross ties between the front and middle frames. Drive-ins are also the most prone to lift truck abuse, since the trucks drive in and out of each tunnel. Therefore, quality engineering and robust manufacturing are both critical to a successful installation.
Over Single Selective Racking
The level of improvement depends on the depth of the drive-in. In theory, the deeper the drive-in, the greater the improvement. But, proportionate storage improvements will only be realized if capacity utilization is at least as high as in selective racking. That said, for a 4 deep back to back system, the improvement over selective is as follows:
- Floor space savings of 35-40%.
- Storage capacity increases of over 50%.