Even though the wheeled carts in industrial pushback rack storage systems are designed to travel smoothly backward and forward from the point of pallet insertion and removal, jams can sometimes occur. Common causes of hang-ups include:
- Improper loading of pallets.
- Broken pallet boards.
- Overhanging items in the load (slip sheets, carton flaps, loose stretch wrap, improperly stacked cartons, or boxes that have been jarred out of position).
To safely un-stick a pallet in a pushback lane, there are several approaches. Notably, none involve an operator climbing in front of a live, loaded pushback system. Doing so has a high potential of injury.
Prevent Hang-Ups in Pushback Rack
First, there are several preventive measures that minimize the risk of hang-ups, such as:
- Only use the types of pallets for which the system has been designed.
- Do not place pallets whose loads have not been stretch wrapped or unitized into the pushback system.
- Carefully inspect each load prior to placement in the pushback lane to ensure proper unitization and no product, slip sheet, or stretch wrap overhang.
- Do not place damaged pallets or those with broken, split or cracked bottom boards, or exposed fasteners into the system.
- Always control the speed of the load with the forklift when inserting and removing a pallet. This prevents pallets from advancing too fast and potentially colliding with each other or the front of the system. Such impacts can prompt boxes to come loose and fall, creating a jam.
- Do not mix load weights within a single lane, as it increases the potential for a heavier pallet to push a lighter one out of alignment or out of the system.
- Do not side-shift a pallet resting on a pushback cart. Doing so will likely knock the cart out of alignment and off the rail.
- Periodically inspect the system’s carts and rails to ensure all components are intact and that any debris or other material is removed.
How to Clear a Jam
If, after following all the aforementioned best practices in preventing hang-ups, a jam still occurs, these are the recommended steps for clearing the lane.
- Operators should never climb into a live pushback lane to attempt to clear a stuck pallet, as the risk of a serious injury is high. Instead, remove all pallets from an adjacent pushback lane first.
- Position a forklift to hold the jammed lane in position. Secure the adjacent—now empty—lane with tie-offs. Then, an operator can enter it on a man-lift to ascertain the cause of the hang-up.
- From the adjacent empty lane, the stuck load can be freed from the side. If it is not possible to easily clear the obstruction, unload the pallet from the side to remove the weight of the load before releasing the blockage and removing the pallet.
- After resolving the hang-up, unload the jammed lane with a forklift. Then, inspect the lane’s pushback rails and cart wheels for damage and/or debris. Clean as necessary prior to reloading. (Find more tips on the safe use of pushback rack systems here.)
Looking for more storage rack safety guidelines? RMI will be presenting a free educational seminar, “Storage Rack Safety 101,” on Wednesday, April 10 at ProMat 2019 in Theater F at 11:15 a.m.
