Determining Sling to Load Angle Factor with a Tape Measure
What is a Sling to Load Angle Factor?
How is this figured out?
How is this done easier in the field?
The problem can be done easier with a shortcut called "The Ten Inch Rule". Once the load is rigged, with a tape measure, find where the sling is 10" high over the load - you do not have to measure the total height of the sling, only to the point where it is 10" above the load. Measure from this point, down along the sling to the attachment point, giving you the sling length. Example: If the sling, from the 10" above the load to the attachment is 16.25 inches long, simply take the decimal point and move it one place to the left, making the SAF 1.625 (or 16.25 divided by 10). Fast, Simple and Easy!
Important to Remember: If your measurement of the sling from 10" above the load to the attachment point is greater than 20 inches, that means the SAF is greater than 2 and the angle is less than a 30-degree horizontal angle. Therefore, the load must be re-rigged prior to picking.