Pallet storage racks are the backbones of the warehouse, but there’s more to them than meets the eye. When considering a new racking system, an important first step is understanding the difference between structural steel racking and roll-form (sometimes referred to as cold-rolled) construction.
Roll form construction is the most common type of racking. Rack manufacturers build it by running a roll of light-gauge steel through a series of roll forming machines, bending the steel to create a final shape. It is the shape of these components that give it its weight-bearing capacity. Conversely, structural steel rack consists of hot-rolled steel members (such as C-channels) that are inherently heavier than the cold-rolled counterpart.
Structural steel is inherently more impervious to damage (from lift truck impact as an example) and may be able to carry as much as 80% of the rated load, even if there is deformation to the rack frame leg until repairs can be made. Roll-formed rack should be immediately unloaded if damaged since deformation significantly decreases load bearing capabilities.
There is also a hybrid version which often uses structural steel uprights with roll-formed beams (shelves). This provides the advantage of impact protection at the upright leg while offering the lower weight and cost of roll-formed components.
Making the choice of pallet rack system more complex is the issue of selectivity vs. density. Single selective, double-deep, push-back, drive-in, drive-through, and pallet flow iterations must be aligned with your inventory and velocity (movement) profiles. Additionally, aisle width and the appropriate lift truck must be engineered to provide the most favorable balance between space utilization and throughput productivity. Counterbalance trucks, reach trucks, swing-mast trucks (turret), and other technologies must be compared as part of a thorough cost-benefit analysis.
Finally, all systems must meet Federal, State, and Local building and life-safety codes and should comply with American Institute of Steel Construction (AISC) and Rack Manufacturer’s Institute (RMI) standards. There is no one-size fits all solution when it comes to pallet rack design and selection.
