As companies continue to expand product lines while shrinking overhead expenses, the need for safe and efficient storage continues to grow. Few companies have the luxury to increase their facility footprint or move, and when they do, it’s expensive. Further increasing the need for space are efficient manufacturing methods calling for sub-assemblies as well as higher raw material inventory (in some cases) being carried to allow for longer overseas lead times.
Many facilities have an underutilized space above the floor (see example, figure 1). Floor space is often completely consumed with operations and storage. However, when properly planned and built, there is vertical space which can be leveraged, increasing storage and efficiency in the same facility for a much lower cost (see example, figure 2).
Cantilever racks are the racking system of choice for the orderly storage of large, bulky items with a wide range of lengths and size proportions. The horizontal load carrying arms of the cantilever rack system extend outward from a single column, while pallet rack design includes front columns. Because they are not restricted by front columns, cantilever racks provide full horizontal access with no lost storage space due to rack structure. This easy access enhances the retrieval efficiency and minimizes potential damage often caused by horizontal or vertical obstructions.
Bluff Manufacturing’s custom Cantilever Racks are always designed and reviewed by our Engineering Department to make sure that the weight distribution of your products will be safe and stable in the cantilever rack. In some cases, depending on the shape, density, weight distribution, and overhang of your product, the construction of the arm or base may require additional size, strength or bracing to safely store the load. How the storage solution evolves is based on your needs, your site, and your product.
Once your new cantilever rack has been installed and loaded with product that used to be farther away or on the operations floor, the efficiency of your facility increases. More available work area is put into service, allowing for faster throughput.
Vehicular operations, fuel, and maintenance costs also have the potential to decrease as the product can be efficiently stored closer to where it is needed. This saves on the length of the trips required to carry product back and forth and greatly reduces cycle times. The ease of use, and thus the efficiency in placing and picking large items in the cantilever rack is also greatly enhanced over traditional rack. Furthermore, the increased space created by the cantilever rack gives forklifts more room to maneuver and reduces damage to and repair costs for racks.
Safety also increases in the warehouse in multiple ways. Personal safety has been increased because the vertical storage eliminates tripping hazards by getting materials or finished goods off the floor and into the rack. In some cases, the open space helps increase forklift safety as well by reducing injuries associated with trying to maneuver in small spaces and bumping into people.
Despite the best advance planning for the installation of a cantilever rack, many companies have found additional efficiencies beyond what they anticipated. The space which is created by vertical storage triggers an initial review of how to do things better. But as with many process changes, the “domino effect” has the potential to create a larger impact:
A common misconception is that when a rack load spans (3) or more arms in a continuous rack system, the load is always equally distributed between the arms. Actually the interior arms may take a greater load than those on the ends, depending on how much overhang is present. For each cantilever rack we engineer, we will need specifics about the size, weight and weight distribution of your product. For one specific example, the following specs were developed:
The generic formula that outlines the arm load capacity requirement in a continuous rack system depends on the following factors:
Consideration of fewer than all of these factors shows how assumptions about the load distribution can quickly lead to under-sizing of the arms and a resulting unsafe situation.
When Bluff’s Engineering Department calculates the load requirements of the structural steel members, we size the arms, columns, and connections to account for all the above elements as well as seismic loading and AISC 360 specifications.