The Use, Inspection, and Fall Clearance Distance of Fall Protection Equipment

Self-retracting lifelines (or SRLs) have been in use for quite some time and, have gotten smaller, lighter, and more inexpensive; they also became more commonly used.

ANSI Z359.14-2012 provides guidance on performance, design, testing, markings, instructions, inspections, maintenance, & storage. In 2012, ANSI created two classes of retractable fall protection, which they call A and B.


  • Maximum arrest distance not to exceed 24”
  • Average arresting force not to exceed 1350 lbs


  • Maximum arrest distance not to exceed 54”
  • Average arresting force not to exceed 900 lbs

SRLs class A vs B

All in all, the difference between the two classes is 2.5 feet of fall distance and 450 lbs of arresting force. What does this mean to you, the user?

The maximum arresting force probably won’t play into your planning very much. When worn with a body harness, both classes meet the OSHA requirement of limiting the arresting force on the human body to 1800 lbs.

However, when planning your fall protection, the maximum distance will figure into your fall distance calculation. Knowing which class your retractable is will allow you to use the proper value (24” or 54”) in your calculation. An extra two-and-a-half feet of fall distance is significant and if not figured in your fall clearance can lead to serious injury.

To make it easy, ANSI suggests that these classes should be listed on all product labels. Don’t let the A and B classifications themselves confound you; they are important but simple. Now you know the difference. And, as a certain real American hero/toy used to say, “Knowing is half the battle.”

Due to their relatively complex nature, self-retracting lifelines require a bit more attention. Unlike lanyards, whose vital components are readily accessible, much of what makes an SRL an effective piece of equipment is hidden from view. Springs, brake pawls, pressure plates, and even the cable or web assembly itself are all contained unseen inside of the housing.

When you inspect the cable, looking for kinks, twists, birdcages or the like, don’t forget to also inspect the swage termination! On a cable SRL you will see a black, rubber handle at the end of the cable next to the snap hook. Underneath this handle is the swage termination. To inspect this part of the cable, extract a small amount of lifeline from the SRL then slide the rubber handle away from the snap hook. Check all contact points of the cable as it passes through the swage for loose/broken strands or harsh bends.

Required SRL safety inspections include an inspection by the user prior to each use as well as inspections performed every 6 months by a competent person who is not the user.