Posted: 11 Apr '13

Factors that Influence Fall Arrest Forces

Force Values Created During Fall arrest

Even with complex engineering calculations we are not able to accurately predict which the force values will be created in a fall. This is due to many factors such as; if the anchor beam you are attached to flexes, if your anchor sling tightens around the anchor, if your lanyard has any stretch to it, your harness might be a little loose fitting and may slide, and how “soft” you are due to layers of clothing and body fat, factors like these will decrease the arresting forces.

Even though calculating force values is complex and unreliable, the solution is simple, minimize free fall, and use a energy absorber.

Equipment Selection and Maximum arresting force

The equipment we select will play a vital role in minimizing arrest forces in a fall, first off, always use a personal shock absorber. Locate your anchor as high as possible to minimize free fall distance, Ensure the anchor is overhead, swing falls can create large arrest forces. Some permanent anchor points such as “tip over cans” and “Zorbit” energy absorbers are specifically designed minimize the forces of a fall. Our connector choice also influences maximum arresting force, for example using a lanyard that is adjustable can help us remove free fall distance, or using self retracting devices can shorten or eliminate our free fall distance. These will all help to minimize our maximum arresting force.

Canadian Society of Engineering Safety Alberta Construction Safety Association Canadian Safety Standards Training Alliance