Fort Worth, Texas (PRWEB) August 14, 2012
As Bluff Manufacturing operations continue to expand, the available work area within the established production floor remains constant. This presented a challenge as relates to balancing the available work area and required storage queue capacity to enable the continuous production process. It was noted that the available horizontal area had been completely consumed with operations and storage; however, there was vertical space which had not been occupied at the time.
In an effort to increase the efficiency of the facility, increase storage and operations per area, it was determined that storing the sheet stock materials in a vertical configuration would provide a solution. Given the self-supporting bulk sheet stock it was determined that the most economical vertical storage solution was the heavy duty cantilever rack system. The advantages to putting this storage system in place were that it increased the efficiency rating of the facility as a whole, decreased vehicular transport operations time and cycles to handle materials, and provided safety advantages for both operators and vehicles.
The materials to be stored were sheet stock of steel and aluminum ranging in size from 60”x120” to 60”x240” with thicknesses varying from ¼” to ¾”. It was observed that these bulk materials are relatively self-supporting and bulky at up to 20’ in length. It was desired by Bluff operations staff that each level hold (25 kip) of sheet stock and be supported by arms at least (60”) long to accommodate the widest sheet.
In regards to sizing the cantilever rack arm required a common misconception that has been observed is that when a rack load spans (3) or more arms in a continuous rack system, customers are under the impression that the load is equally distributed between the arms. Actually the interior arms take a greater load than those on the ends. For example:
3 Arm Continuous System:
Interior Arm: 50% of total load each
Exterior Arm: 25% of total load each
4 Arm Continuous System
Interior Arm: 33% of total load each -> (8.34 kip/arm)
Exterior Arm: 16.7% of total load each
The generic formula that outlines the arm load capacity requirement in a continuous rack system is as follows:
(# of Bays) = (B)
(Total Load) = (TL)
Interior Arm: (1/B) = % or (TL/B) = Load per Arm
Exterior Arm: (1/B)/2 = % or (TL/B)/2 = Load per Arm
If it would have been assumed that the total sheet stock load was evenly distributed between the 4 arms per level equally, then the total load per level: (25.0 kip), 4 arms per level, load per arm (6.25 kip/arm) would have led to under-sizing the arm (6.25 kip)/(8.34 kip) = (0.749) --> 25% Percent error of under-sizing decreases inversely as the number of bays increases linearly.
This load requirement given the arm length was beyond the load capacities of Bluff’s standard cantilever rack system. Thereby the complete system was reviewed by Bluff’s engineering department to increase the arm, and column sizes to accommodate the load requirements. With this load distribution taken into account the arms, columns, and connections were sized appropriately to account for impact loading and seismic loading as outlined in RMI, which defers to AISC 360 in the design of the structural steel members.
The efficiency of the facility as a whole increased. There is now more available work area to be put into service where the sheet stock had originally been stored. Vehicular operations are safer as they have more room to maneuver during the loading process were as before they had to work around piles and drag sheets around to get them into position to be able to lift the sheet stock. Vehicular operations, fuel and maintenance, also have the potential to decrease as the sheet stock no longer has to be drug around on the floor to get in position to be lifted, thereby saving on forward and reverse cycles. Personnel safety has also been increased as it was observed that operators would walk over the piles of sheets which create a tripping hazard. Now there is a single plane floor to enable safer egress.
As any manufacturing facilities’ operations expand the available work area within the established production floor area, the effort to increase the efficiency of the facility, increase storage and operations per area until, can be assisted with a heavy duty cantilever rack system that can store self-supporting bulk materials in a vertical configuration. The advantages to putting such storage systems in place can increase the efficiency rating of the facility as a whole, decreased vehicular transport operations time and cycles to handle materials, and provided safety advantages for both operators and vehicles.
For additional information about a mezzanine, contact Bluff Manufacturing at toll free (800) 433-2212 or http://www.bluffmanufacturing.com.
About Bluff Manufacturing
For more than 40 years, Bluff Manufacturing has been recognized as an innovative leader in the fabrication and design of high quality dock, warehouse, and industrial safety equipment. Bluff Manufacturing, whose customers include Frito Lay, Lumber Liquidators and ABF, is the only company to meet the American National Standards Institute’s (ANSI) MH30.2 standard, ensuring the highest quality products and providing customers with the greatest possible value. Based in Fort Worth, Texas, Bluff Manufacturing serves the entire U.S., Mexico and Caribbean through a national distributor network, and the company’s 11 distribution warehouses ensure quick delivery of the standard items in the company’s product line including yard ramps, dock boards, dock levelers, wheel risers, and safety barrier product Crash Guard.
Bluff Manufacturing acquired B&L Structures in June 2010, expanding its portfolio to include work platforms, mobile units, stairways, free standing conveyor support structures, caged ladders and steel mezzanines. These products continue to be available through B&L’s national network of distributors, many of which also work with Bluff Manufacturing.