Industrial Shelving: How To Prevent Collapses and Falling Products
When shelving fails, the "domino effect" can bring down an entire row -- or more
What are some steps you can take?
- Give your loads some breathing room: One of the easiest ways to knock something off a shelf is to have too many items stored on it. Everyone who has worked in order picking probably can cite an incident where grabbing a stored box or bin pulled off the one beside it. That happens due to proximity; an edge catches on an edge. Keeping gaps between product may eat more floor space and require more shelves, but if you have the area to work in, it helps.
- Add a front strip to shelf levels: For picking operations that use shelving to hold bins, one of the easiest ways to drop product is to pull an entire bin out while reaching for parts.
- Slot difficult items in the “golden zone.” Retailers store their most profitable, most purchased items in the mid range, eye-level, easily-reached shelves in part due to increased sales, but also for ergonomic and accessibility reasons. You should do the same in your product slotting scheme. Putting the things most needed on shelves where it’s easier to get them means your pickers will not have to reach or stretch as often, which means they won’t drop products as often — or knock an adjacent product off the shelf.
- Guard the outside face of shelving on mezzanines: An order picker can easily push a stored item through to the other side, where it can fall to the floor level, which can result in product damage and present some danger to workers on the other side. To alleviate this, use closed back shelving units or install safety nets on the outside of your shelving to help stop items from falling out.
- The heavier it is, the lower it should be stored. Like pallet racks, shelving does better if the heavier loads sit on lower levels, not higher. Although most shelving (like most rack) is designed to store heavy loads on higher levels, if you have a choice, it’s better to balance your loads this way.
- Make access easy. If you have tall shelves, rather than forcing workers to reach or strain, provide shorter rolling ladders or stools for access.
Shelving collapses and how to prevent them
Pallet racks collapse more often, more dangerously and more spectacularly than shelving, but your shelving will collapse and spill items in expensive and potentially dangerous ways if you don’t set it up right. Like racks, most shelving rows are tied together, which means that the domino effect (one unit pulling down everything) could very well happen if a shelving unit becomes overloaded or unbalanced, gets hit or otherwise falls. Some factors in reducing shelving collapses:
Loading and load management is critical
Heavy industrial shelving can hold lots of weight–more than a thousand pounds per shelf in the right configurations. But it does this only in evenly distributed configurations. If you are loading very heavy items, you need to ensure that you center and balance the loads.
With shelving (as opposed to racks), loading happens by hand, so when you load heavier items on shelves, you face some risk of pulling the shelving down or pushing it backwards. Be sure your team observes best loading practices for loading/unloading items. For instance, if you have a shelf with three bins, all full of hardware, and one bin is picked more frequently than the other two, be careful that the difference in weight doesn’t unbalance the unit. You may need to reslot your inventory to get this right.
Pay attention to load capacities
These types of incidents are very possible in any warehouse where shelves are overloaded. You should clearly mark the capacity of each shelf, and post that on your shelving.
Protect the shelving from impacts
If your storage area adjoins aisles of forklift or pallet jack traffic, a nudge can bring down an entire row or multiple rows. Consider traffic management, guard rails, bollards or other protective measures for these situations. Although shelving is not always bolted to the floor, in some cases it should be. You may have to check your shelf type and manufacturer specs to understand whether that’s required or recommended for your shelving units.
Assemble your shelving to manufacturer specifications, maintain it and inspect it regularly
Be certain your shelving was properly assembled and installed. Post-installation, inspect your shelf clips, rivets and other connections. Like rack, shelving consists of uprights (posts) and shelves that connect to them. If clips are loose or connections not fully seated, there is potential for a collapse. Regularly inspect to ensure no shelving units are leaning, have loose shelves or have damaged components. It’s important to understand that inspecting any storage equipment that holds heavy inventory is a good use of your time and resources. Not only will you reduce product damage and prevent calamitous loss of inventory, you’ll protect your employees and also get a chance to find other issues in the operation.
Tags: warehousing, shelving, plant safety, Inventory protection
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.