How to Prevent Pallet Rack Push-Through Accidents
Stop pallets from falling into aisles and flue spaces
When heavy pallets are stored on horizontal beams in your pallet rack system, there is always some danger of a pallet or items stored on it, being pushed through the back of the rack. Items or full pallets can then fall or push the pallet behind them toward the next aisle in double row systems. What are some options to reduce the hazards related to push-through accidents?
The impact of push-through accidents
Push-throughs in single and double row selective rack systems
Above, left: when pallets are pushed through a double rack row, the full pallet or components of it can fall into the next aisle, endangering workers and causing damage. Above, right: Single aisle racks have the same issues, but can also result in pallets or loads being pushed into a wall or other structural element. In both configurations, push-throughs can compromise pallet rack structural integrity in ways that weaken or damage the rack over time—and are often hidden out of sight at the back of the rack.
Structural stability and push-throughs
When a pallet isn’t seated correctly on the beams, its weight can cause instability for the entire rack. Racks are manufactured to hold specific weights in specific configurations, and all of those calculations are based on evenly distributed loads. If heavy pallets aren’t sitting square on the rack, its weight bearing capacity is reduced. The entire structure could become unstable. Loading always affects the structural integrity of pallet racks, so it’s critical to eliminate push-through loading.
Product, rack and facility damage
Above: in this situation, where people work below in the next aisle, push-through accidents can be particularly dangerous.
Rack damage
When a pallet is pushed too deeply into a storage position, it can damage the pallet rack by exerting lateral force on the beams, uprights or other components. Safety clips can be snapped, bolts sheared. Cross supports can be stressed or even broken. This damage may be invisible, particularly if it occurs at the back of the upright where it is difficult to see. Over time, this damage compromises the rack system’s structural integrity.
Product and inventory damage
Pallets that are pushed through the back of a rack system can dump their loads, either into flue spaces or into the aisle. Cartons can be crushed between two pallets. Bags can be pierced and spill. Heck, even the pallets themselves can get crushed with the force of a counterbalanced lift truck pushing them into another pallet.
Facility damage
When pallets are pushed too deeply into a rack against a wall or adjacent to a column, they can damage that structure. Ductwork, electrical conduit and sprinkler systems mounted on the building structures are at risk.
The primary concern is safety when it comes to rack loading and push-through issues. The chance of full or partial pallets falling into work areas where people are present is always there. Since improper loading can weaken racks, it can cause collapses, making preventative training and precautions critical for warehouses.
Options for reducing push-through accidents
Rack safety straps & panels
Rack straps are single, polyester straps that fit onto teardrop or bolted uprights. They’re available in widths from 8 to 13 feet. Place at least one strap at the base so it pushes back when pushed by an incoming pallet.
- Advantages: Rack straps are flexible, rather than rigid. When pushed to tension, they tighten to signal the driver that the pallet is at its limit. Because of this flexibility, they may not damage components, as there is play in the tension forklift drivers can feel as they push pallets into position. Straps are probably the most economical way to provide front-to-back limits for pallet positions and they install easier than any other alternative–the clips/hooks just drop into place. You can install as few or as many as needed, so you could put one strap to limit pallet position and others higher in the bay to reduce product dislodgment. Straps are easier to move, remove and reconfigure than any other alternative. If you need to access the back of a single deep rack, you can easily remove and re-attach the straps.
- Limitations: Flexible guards aren’t as sturdy or rigid, so it’s possible for a driver to push entirely through easier than with back beams or other rigid protection. These straps are strong with over 2,400 pounds resistance, but not as strong as some rigid/metal alternatives.
Straps can also be equipped with mesh panels, which provide coverage for the entire back of the rack bay. Panels have the same easy installation, and can be moved, removed and re-installed with ease. You can also use a sliding panel, which lets you access inventory behind it with ease.
Read more: The Importance of Pallet Rack Row Flue Space – and Ways to Maintain it
Rigid wire panels
For full-bay rigid coverage, rack backing wire mesh panels bolt directly to teardrop uprights, and can be mounted flush or offset for overhang situations. Constructed with 2″ x 2″ 10-gauge welded mesh, panels are one of the most rigid options.
- Advantages: Most rigid methods—like beams and stops—provide only partial coverage and can allow cartons or other partial loads to fall. Panels contain full pallets and everything on them within the rack structure. For work aisle protection, panels are the most comprehensive option that combines rigid strength and full load containment. You can enclose a bay with side panels and doors to create a secure storage rack if needed.
- Limitations: Installation is more expensive and difficult than netting, backstops or beams. Full bay coverage like panels and safety nets are usually reserved for aisles overlooking work spaces, not the internal side of a two-deep row. However, if product drops are an issue, panels can serve that purpose.
Pallet rails with backstops
These 1/4″ steel rails fit on the sides of uprights to guide pallets as they enter the rack structure. They also provide backstop protection on each side of a double pallet bay by adding a 10-inch backstop on each side of the bay.
- Advantages: This method protects the upright from side bumps, as pallets are meant to slide along as they’re parked on the beam. This lets you better regulate the lateral position of stored pallets. Bright safety yellow finish makes both the side rail and backstop tab more visible.
- Limitations: the tab is only on one side of the pallet, and serves as more of a warning than a stop. If a driver pushes a pallet against it, the pallet can potentially skew at an angle under pressure. Generally drivers will feel the resistance and quickly stop pushing. This method only applies to two-wide racks and cannot protect a three-wide system.
Pallet back stop beams
Load stop beams are specialized rack beams installed on the back of each rack row for rigid protection. They can be bolted onto the rack on the back of each bay. Drivers will feel pressure from them if they push the load too far back into the rack structure.
- Advantages: Beam stops are easy to install, since they bolt into standard uprights. They’re built with 6″ flue space offsets, meaning that double rows that use them will have 12″ guaranteed space for fire code compliance. They cover the entire bay, allowing them to stop every pallet for longer beam widths with three or more pallet positions.
- Limitations: Backstop beams are a single point of protection, which means that they will stop the pallet, but may allow wider loads to push too far. The beam cannot prevent a carton or other part of the palletized load from falling. Like all methods of rigid protection, they can put pressure on the rack structure if hit too hard.
You can also install a regular beam on the rear side of a rack to help guard against push-through issues, but that doesn’t allow any offset spacing and usually limits pallet sizes too much for general use.
Rack safety netting
Rack safety nets protect people who work in the aisles below from falling pallets, partial pallets or partial loads. They’re flexible protection, so they give first before resisting pressure. They are installed the entire width of a rack bay (or a longer run of racks), typically over any aisle where others work before. They can be installed on extenders above the top level so that they protect from load drops off the top beam.
- Advantages: Netting protects the full width and height of a bay. It’s much more likely to catch a falling carton than straps, back beams or metal stops installed on beams. It can be installed flush with the back of the rack or with overhang spacing. Its flexibility gives your drivers feedback on their position as it’s stressed backwards, so they have time to stop pushing the pallet any deeper than the netting allows. It has a range of capacities from 1,000 to over 5,000 pounds, so you can specify it to match your load.
- Limitations: Its full coverage comes at a price – it’s costlier than partial coverage solutions. Rack nets can be used on the interior of a two-deep row, but are typically reserved for the exterior of a bay that overlooks a traffic aisle or work area. For flue space maintenance and push-through protection on double deep aisles, netting may be overkill. Netting tends to be more expensive to install than other alternatives.
Modular safety nets are easier to install than standard ones, but have lower capacity ratings.
Beam load stops
These brackets provide a hard stopping point for pallets as they’re pushed into the rack structure. They fit over a beam, either flush or offset with a 3″ overhang. When pallets are placed, the bracket stops them from pushing past. Drivers will feel the resistance when their pallets press against the steel bracket and realize the pallet is now situated fully at the back of the rack. Each pallet position should use two brackets for even loading.
- Advantages: Easy to install, rigid protection; painted safety yellow for visibility. Can easily be moved for reconfiguration or changes in layout. An excellent solution for problem areas.
- Limitations: Since they’re rigid, there is almost no give. Enough impact can snap the bracket or push against the beam/upright connection. If not correctly spaced, pallets can skew on placement. You’ll need to be certain of your rack beam size, since they’re specified by beam depths and heights.
Protecting what matters most
Because rack collapses and falling loads pose dangers to people who work around racks and forklifts, prevention methods should focus first on preventing accidents that might hurt people. If you need assistance with rack safety and layout, contact us for fast assistance.
More resources
- Pallet Rack Evaluation: Safety
- How to Specify Rack Safety Netting
- Pallet Rack Safety Standards: What you Need to Know
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Tags: Safety & Ergonomics
Scott Stone is Cisco-Eagle's Vice President of Marketing with more than thirty years of experience in material handling, warehousing and industrial operations. His work is published in multiple industry journals an websites on a variety of warehousing topics. He writes about automation, warehousing, safety, manufacturing and other areas of concern for industrial operations and those who operate them.