Drive-in racks are warehouse racks that forklifts can drive into to access the pallets. Standard selective pallet racks have load beams running horizontally across the racks to support the pallets, but a drive-in rack gets rid of the load beams to allow forklifts to enter each bay. Instead of being supported by load beams, pallets are supported by a set of rails on each side of the bay.
With drive-in pallet racks, the forklift can only access the pallets from one side. The skids are essentially stored in long aisles that the forklift driver enters from the end. Since there is only this one entry and exit point, the pallets in the back cannot be reached while there are pallets in front of them. This requires material be stored following LIFO principles, or Last In First Out, since the last pallet placed into the rack has to be the first one to be removed.
When to Use a Drive-in Rack
Drive-in racks offer maximum density at the expense of selectivity. Each pallet is stored right next to its neighbouring pallet. There’s no wasted space. No aisles between racks for forklifts. Forklifts just simply drive into the racking system. Unfortunately, it is much more difficult to access individual pallets if they are needed.
Since the pallets cannot be rotated easily, drive-in racks are generally used to store pallets holding a single SKU. This way it doesn’t matter which pallet is used; they’re all holding the same goods. To prevent the last pallets at the back from beings stored forever, it is good practice to empty out the entire rack regularly. If the volume of product is high enough, multiple lanes can be used to allow for stock rotation.
Goods that are seasonal are prime candidates for storage in drive-in racks. During the off-season, the inventory can build up in the rack and not have to be moved. When peak season arrives, the rack is emptied quickly due to the high demand.
Due to the high density of drive-in racks, they are often used in cold storage warehouses. The high cost of refrigerated storage and the ability of solid objects to hold their temperature longer than air are major factors in this decision to pack goods closely.
Drive-in Rack Features
Drive-in racks are typically fabricated out of structural steel, a heavy duty material that can take some abuse. These racks will be subject to more damage since there is more opportunity for the forklift to hit the structure.
Since there are no load beams, the racks are supported with horizontal cross members at the top and at the back. This ensures that the structure is rigid and will support the load of the pallets sitting on each set of rails.
Each manufacturer has a unique design for the rails that support the loaded pallets, but most have a tapered lead-in at the front of the bay to make it easier to line up the pallets to the rails.
Many drive-in racks have offset front supports, to enable the forklift to enter easier. This way the driver can line up the pallet to the rails without worrying about the forklift hitting the side of the rack. Naturally, the forklift has to be narrower than the pallet, but conventional counter balance forklifts are perfectly fine.
The length of a drive-in rack is only limited by the storage area dimensions. The longer the rack, the more cumbersome it is to drive in and out regularly, however. Some manufacturers offer heavy duty rails along the bottom to protect the structure.
Why not just stack all the pallets on top of each other?
Since a drive-in rack is holding the pallets so close together, why not just stack all the pallets in top of each other? This storage method, called “block stacking” doesn’t require a rack at all and has the same selectivity as a drive-in rack.
It’s definitely less expensive to block stack, but in many cases it’s not possible. Some products cannot be stacked safely due to their geometry. Pallets of product that comes in bags like dog food or fertilizer, will not sit squarely on top of each other. Extremely light product, like boxes of cereal or toilet paper may collapse under the weight of the pallets above them. A drive-in rack will allow these types of product to be stored safely.
Are drive-in racks right for your application?
If you’re not sure if the density of drive-in racks will work for you, consider the balance between usable storage capacity and density. You may think you’re saving money by packing things denser, but when storing one SKU per lane, how full will it be?
Check out this analysis at LIDD Supply Chain Intelligence.
Some examples of drive-in racks:
A simple computer generated video of a forklift loading a drive in rack.