20. What is Fall Factor?
Fall Factors are something that every rescuer and climber should understand. Understanding fall factor will help a climber/rescuer determine when and how often to place anchor points. Because it is impossible to fall farther than twice the length of the rope, the highest possible fall factor is 2 (except via ferrate). A fall of 8 meters on 4 meters of rope (8/4) is a fall factor 2. So is a fall of 40m on 20m of rope (40/20 = fall factor 2). It is important to remember that fall factor is not the only determinant when calculating impact force; overall length of the fall, friction from anchors, weight of load, as well as the manner of belay (whether dynamic or static) also greatly affects the impact force.

 

 

 

21. What is a 3-Sigma Rating?
3-Sigma ratings are used throughout the climbing and rescue industries to determine a level of accuracy in the breaking strength numbers that we report. A 3-sigma rating is much more reliable than, say, an average strength where 50% of a sample could be below that strength. 3-sigma ratings are based on a statistical analysis of the breaking strengths of a given sample of rope. Statistically speaking, a 3-sigma rating means that 99.9% of the products are stronger than the reported MBS rating. What this means is a 3-sigma rated MBS is three standard deviations below the average breaking strength. Standard deviation helps to define the spread in the distribution of a given test sample. It is not the mean. Reporting 3-sigma ratings more accurately represents a rope's strength to be at least the MBS reported.