Our cantilever rack manufacturer, Steel King, has put together a useful cantilever rack design resource. Following these 5 steps will serve as a useful cantilever design guide.
1. Determine the number and spacing of support arms.
1a. Use enough arms under a load to prevent deflection of the load. Deflection causes undesirable side pressure on the arms. Using wood blocks on the floor under the load,test your load for deflection on a two-support system.
1b. If you do not detect any deflection, you may use two support arms. The arm capacity required will be half the load weight, and the upright centerline will be 1/2 of the load length.
1c. If you notice deflection with two supports, try three supports. If this system works, arm capacity will be 1/3 of the load weight, and the upright centerlines will be 1/3 of load length. If three supports are still not enough, add supports as necessary until deflection is eliminated. Note: Product should overhang the end of the rack by 1/2 of the upright centerline distance. Loading without overhang is incorrect.
2. Determine arm length. Arm length should equal load depth.
3. Determine upright height.
Start with base height:
+ number of storage levels x load height
+ handling clearance [4”to 6”] x number of levels
+ number of arm levels x arm thickness
= upright height.
Note: Check limitations at your plant such as ceiling clearance or fork lift height.
Note: Top arm level must be below the top of the column.
4. Determine capacities required.
Arms: Load weight ÷ number of arms per level
= arm capacity. (Assuming each arm supports anequal amount of the load)
Uprights: Number of arms per side x load per arm.
Note: Load on base is not included in capacity.
5. “Bracing lengths” refer to the horizontal centerline distance from column to column, as in the diagram. See Step 1 for the proper number of braces per type of load.