How Do Push Forces Affect Push-Back Rack Loading & Unloading?

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What You Should Know About Push Forces & Push-Back Rack Safety

Push-back pallet rack is a dynamic, high-density storage system. Wheeled carts flow up and down slightly pitched rails as pallets are loaded and unloaded by a forklift. The dynamic movement of the carts is what draws interest in the system as it provides a productive boost over and above the compact, high-capacity design. However, is there cause for concern as pallet loads in the thousands of pounds are pushed into the lane on an upward pitch? The answer… probably not, BUT it’s best to confirm –here is what you need to know.

Push Back Rack - Apex Companies

Enveloping Carts

How Does a Push-Back System Work?

Push-back racking features individual SKU lanes with carts and rails. The wheeled carts sit at the aisle face in an enveloping stack on top of the rails. Push-back systems are typically between 2- to 6-pallets deep.

Loading: The forklift operator loads the first pallet on the top cart. To load the next pallet, the driver pushes the first pallet back to reveal the cart underneath. Each subsequent pallet is loaded the same way, with the last pallet sitting directly on the rails.

Unloading: Due to the sloped design of the system, the rear pallets will automatically flow towards the pick aisle as pallets are extracted from the lane –the forklift operator controls the speed of the advancing pallets by slowly backing out of the system.

Push Back Rack - Apex Companies

What Are the Push Forces When Loading a Push-Back Rack System?

3-Deep Push-Back Rack - Apex Warehouse Systems

3-Deep Push-Back Rack

The term push force (or lateral push force) describes the pressure of the combined rear pallet weight that pushes back against the forklift as pallets are loaded. The amount of push force changes depending on the pitch, the number of pallets, and the load weights; however, it’s good to calculate the anticipated push force and confirm that your forklift equipment is adequately equipped to handle it before loading your system.

Push Forces Example:

Most push-back rack designs use a 1/2″, 1/4″ or 5/16″ per foot slope –note this will vary by manufacturer. Using the 5/16” slope as an example and calculating push forces as approximately 4% of the combined weight, we arrive at the chart detailed here.

For example, a 2-deep system of 2000 lb pallets adds 85 lbs of back pressure to the forklift, which is likely well within the load capacity of the average forklift—however, the deeper the lane and heavier the pallets, the more consequential the added forces.

As always, better safe than sorry, so ask for a quick calculation and confirm with your material handling equipment supplier.

Forklift Operator Training for Push-Back Rack & More

Ensure your forklift operators are equipped with more than safe equipment… train them to understand your unique pallet rack storage systems. Apex Resources includes system-specific videos for push-back, pallet flow, and drive-in systems.

YPush Back Training Video - Apex Companies ou can also call Apex for on-site group training and OSHA-compliant certification for your team. When it comes to full-service warehouse services, you only need to make one call –Apex does it all.

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