There are several different types of pallet racking with unique characteristics. Although it seems simple, many different factors need to be reviewed before selecting the right type of rack for your application.
Some of these factors include:
- Size and weight of the product being stored
- Is the stored product going to be picked, or is it overstock?
- What type of business are you in?
- Are you in a seismic zone?
These a just a few of the considerations necessary to pick the correct type of pallet racking that will work best for your operation.
The most basic type of pallet rack is selective rack. It consists of uprights and load beams and allows for the storage of one pallet deep x two pallets wide. It’s called selective rack because it allows for all pallets to be stored or retrieved from the aisle.
A denser configuration of selective rack is called deep reach, or double deep rack. This is where two rows of selective rack are placed front and rear. This allows for the storage of two pallets deep x two pallets wide. It requires special deep reach forklifts, but both the front and rear pallets are accessible from the aisle. Its best when both pallets are the same SKU.
A modification to standard selective pallet rack is mobile pallet racking. This system uses high capacity “trollies” controlled by servo motors to move entire rows of rack. Typically, this is single deep rack and is ideal for storing slow moving product in a very dense footprint.
Another type of pallet rack is push back rack. In this design, a number of carts are placed in each level of rack at the aisle. When products are stored, they are placed on the top cart. When another pallet needs to be stored in that location, the pallet in front is “pushed back” to allow the next cart in the stack to be used for the new pallet. This procedure continues until there are no more carts in the stack. The last pallet is placed directly on the rails on which the carts slide. Typically, this type of system allows for four deep storage with all four loads being accessible from a single aisle. The storage is quite dense, but the rack is expensive, and the carts take up some of the available vertical space in the building.
The most cost-effective solution for storing like SKU’s is drive-in rack. In this rack system the pallets are stored single wide, but many (6-12) pallets deep. The forklift drives into the pallet rack system to reach pallets farther back in the system. The issues here are that it is a slow system since the forklifts are within the rack. Also, selectivity is an issue.
There now is an excellent, cost effective approach to store and transport deep lanes of pallets. Raymond offers a system called Radioshuttle, a rack system with robotic transfer carts that travel under the pallets in the lanes and transports them. A forklift or automated system loads the front end and the shuttle transports one or more pallets in a lane back to the near end or to the far end for retrieval. Lift truck operators control several shuttles at one time allowing for much greater productivity, plus shuttles are easily moved between lanes based on demand.
For applications with many pallets of the same SKU or for staging of outbound or WIP loads, Radioshuttle really quite compelling.
Evaluate and decide
Pallet racking is critical to the success of the warehouse. It controls picking efficiency, storage efficiency, and safety. A a well thought out pallet rack design can either enhance or handicap the effectiveness of the capital investment.
The engineers at Abel Womack can guide you effectively through the process minimizing the risk for all involved.
Additional information you may find useful:
How Big a Warehouse do we Really Need? Warehouse Calculations Simplified
Basics of Designing Pallet Racking