Each arm supports an equal amount of the load's weight. By determining the number of arms per level and dividing it into the weight per level, the required arm capacity can be determined.

To determine the required capacity of each upright, multiply the number of arms per side by the load on each arm. In figure D1, each arm holds 2,500 lbs. Twelve arms per side times 2,500 lbs per arm equals 30,000 lbs., which when divided by three uprights, results in a required minimum capacity of 10,000 lbs per upright.

Assuming a 48" arm, the U1061-NS with 10,200 lbs capacity and the U1061 with 12,600 lbs capacity are the only uprights that will handle the load.

The proper arm requiring 2,500 lbs capacity would be either the XHDSA48 or the XHDSA483M.