Rack System Enhancements That Further Mitigate Forklift Impacts
A previous blog entry reviewed a selection of optional guarding accessories. These add-ons are applied at the time of installation—or as a later retrofit—to aisle-side or end-facing rack columns (or to the floor in front of them) to minimize the damage caused by a forklift impact. For operations wishing to preserve the maximum amount of aisle clearance, however, there are a number of options available for safeguarding the rack uprights for impact. These impact protection modifications can be implemented with either structural or roll-form rack systems, as both are used in high lift traffic warehouse applications.
Outlined in RMI’s ANSI MH16.1-2012: Specification for the Design, Testing and Utilization of Industrial Steel Storage Racks, none of these design enhancements will prevent the rack from failing due to a major collision, nor should they be considered a replacement for proper and ongoing forklift driver training and management. Nevertheless, they greatly reduce the chances that a minor, day-to-day impact will cause a collapse. And, in the instance of an impact causing significant damage, they may extend the time needed to safely unload the rack and remove it from commission until it can be inspected and repaired by a certified rack engineer.
Depending on the application, one or more of these design enhancements may be added to a system. They are most frequently deployed on the aisle-facing columns of interior uprights or to both columns in end-of-row or tunnel-bay cross-over uprights, where collisions are more likely to occur.
- Double Columns. In structural and roll-formed rack applications, a second column may be welded to the front column. The additional column reinforces and strengthens the upright. It also provides some redundancy by redistributing the load stress if the front column is damaged due to impact.
- Column Inserts or Reinforcement. Reinforcement sections can be added externally or internally to increase the impact strength and load capacity of the column. These sections can be made from various materials, such as steel or wood. Further, they can be placed inside racking columns to provide added protection against impact damage.
- Heavy-Duty Bracing. Implementing heavier horizontal and diagonal bracing within the rack upright, particularly in the lower impact regions, can also help the upright resist damage caused by a forklift impact.
- External Column Protectors. There are many other column devices that can be added to provide some level of impact protection. Included are steel guards bolted to the floor, steel guards bolted or welded to the column, snap-on plastic and rubber shock absorbing devices, guard rails, floor rails, and more.
- Beam Uplift Protection. Most roll-formed rack beams are installed with studded-type or formed steel connectors with beams clicking into place with spring-type locking devices or clips. Should a forklift driver miscalculate the clearance of a pallet load opening and impact the beam above the load, the resulting contact can create an excessive upward force. This may exceed the spring lock capacity and potentially cause the beam to dislodge. For additional protection against beam uplift, secondary items—such as bolts and J-pins—can be added, locking the beam connections to provide enhanced restraint.
Again, when correctly assembled, maintained and used in an environment where properly trained forklift drivers operate with caution and care, the vast majority of steel storage racks designed to RMI standards will deliver a long, safe service life. For operations wishing to further protect their racking structure, however, these modifications can enhance its resistance to forklift impacts.
Looking for more rack protection accessories? Section 3.4.2 of RMI’s publication, “Considerations for the Planning and Use of Industrial Steel Storage Racks,” offers a detailed review of the options.