This is the first in the series of in-depth examinations of the various warehouse shelving parts.
Last month we touched on the basic parts, noting that beams are the most recognized warehouse shelving parts. They are the support of any warehouse design, and they must be selected for safety, efficiency and ROI. The choices in beams are not too overwhelming, but where do you start?
You start by asking questions, of course – of yourself or your own company’s packaging department. Know your own inventory. Know how it will be arriving. What is the packaging like? Will it arrive in boxes, crates or containers? Will it be on pallets? If so, what type? How heavy will each box be with and without the pallet? How will the boxes be unloaded from the truck and put on the shelves? Answers to all of these questions will help you to determine a starting point for your beams. Remember that beams should be chosen based on how much they can hold, or their load-bearing capacity. The “load” – meaning the box, pallet or container – will sit directly on the beam. The sturdier the beam material, the more load it can handle, but this is not the only factor in a strong beam. It’s as much about the design as it is about the material.
Basic calculations using a 1.67 load factor will determine the load-bearing capacity, and your warehouse materials sales person or designer should be able to calculate the capacity necessary for your product. The beam manufacturers themselves also provide charts that contain this information so that you can double-check prior to buying. Beams are sold in pairs, and the load-bearing capacity is calculated for the two beams according to the rules of uniformly distributed loads. If you have product that is packed differently or not uniformly distributed, you’ll need a special set of beams and/or racking system to handle the issue. Your design consultant can help you.
Standards set by the Rack Manufacturers Institute (RMI) for all parts in the rack system are used to calculate beam capacity. You don’t need an engineering degree to understand the basic choices in beam construction, but if you are designing a warehouse space, the knowledge is valuable. Your choice of beams can allow more product to be stored both across the beams and on top of them, impacting your profitability as well as your product accessibility. Each design can conform to your space, resulting in a personalized, efficient warehouse. Beam types: simply supported, fixed, overhanging, continuous, cantilever and truss.
Simply Supported: A simply supported beam is just that — simply supported on both ends. The middle section is unsupported and can rotate. Many examples of this can be seen in bridge construction and highway overpasses. Sometimes one end of the beam is supported and the other rotates. In warehousing, these beams are usually selected for lighter loads.
Fixed: A fixed beam is also supported on both ends, but it cannot rotate in the middle. You need to be vigilant about the weight-bearing capacity of fixed beams so you don’t find yourself with curved beams throughout your warehouse! Fixed beams are often shorter and better suited for smaller, lighter-weight loads. Tip: If you want to sound like a real pro, ask your warehouse sales person about the beam’s point of contraflexure. He or she will be impressed with your vocabulary, and you’ll know that it is the point at which there is no bending in the beam.
Overhanging: An overhanging beam is an extension of the simply supported beam — literally. The beam itself extends beyond the support on one end. Beams that extend beyond the support on both ends are cleverly called double overhanging beams. A carport or roof overhang is a good example of an overhanging beam.
Trussed: By adding a rod to a beam, it becomes stronger and the point of contraflexure is higher (remember your vocabulary!). These beams are called truss beams and they are often used in parking garages because of their reinforcement capabilities.
Continuous: A continuous beam is one that extends over more than two supports. A long bridge over a river, or a hallway in a school are two instances of continuous beam use. In the warehouse, this is a stable storage area for bigger, heavier loads.
Beams are important in your warehouse as stand-alone shelving, as well as in rack systems, which give you the flexibility of storing upward as well as outward. Take into consideration the upright capacities when looking at beams for rack systems.
Next month: The skinny on vertical stations – stay tuned!