We have been tasked with determining the sling angles for the rigging setup presented on this page. We will use the vertical-to-horizontal ratio table to find an estimated angle corresponding to the ratio. We will need to find the angle for sling setup, ‘A’, and for sling setup ‘B’. Sling setup, ‘A’, has a vertical distance of 4 feet, and a horizontal distance of 3 feet between lift points. To calculate the ratio, we need to divide the vertical distance, 4 feet, by the horizontal distance, 3 feet. After performing the calculation, we get a ratio of 1.33. This ratio corresponds to an angle of 45°. Sling setup ‘B’, has a vertical distance of 4 feet, and a horizontal distance of 12 feet between lift points. To calculate the ratio, we need to divide the vertical distance, 4 feet, by the horizontal distance, 12 feet. After performing the calculation, we get a ratio of 0.33. This ratio corresponds to an angle of 17.5°. We now have completed the task that we were asked for. Sling hey, has an angle of 45°, and sling B has an angle of 17.5°
Problem A
V ÷ H = Ratio
4’ ÷ 3’ = 1.33
1.33 Ratio = 45° lift angle
Problem B
V ÷ H = Ratio
4’ ÷ 12’ = 0.33
0.33 Ratio = 17.5° lift angle