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The Guardian Fall Team Blog

Many of you in the fall protection industry – either manufacturers or end users – are familiar with a few of the basic performance requirements of Self-Retracting Lifelines (SRLs). For example, you know that Class A SRLs must stop a fall within 24” and the average arrest force must not exceed 1,350 lbs.

In addition to the numbers, I’m sure a few of you (probably those of you who use SRLs at work) are thinking, “Sometimes I have to work in the freezing cold and the driving rain. Sometimes it is hotter than the hinges of hades up there on the roof. I wonder if being hot or cold or wet affects the dynamic performance of my SRL as specified in ANSI Z359.14-14?” Wow! Impressive…you have been reading up! In short, the answer is yes! But as with many things regarding fall protection, there are some ambiguities.

First, allow me to explain the conditioning process.

SRL Conditioning Process

What Is Conditioning? 

When I say “conditioning,” I mean subjecting an SRL to specific environmental tests that are designed to mimic the real-life conditions an SRL may experience. Notice I say that an SRL may experience to and not a worker. I clarify this because sometimes an SRL is left out in the weather when not in use and may be subjected to a wider range of environmental conditions than a worker. The idea here is that a manufacturer like Guardian wants to make sure an SRL will perform as designed even if between uses it has been subjected to extreme heat, cold, or moisture. Lives, after all, are on the line – literally.

Three Types Of Conditioning

According to ANSI Z359.14-14 (4.2.8), SRLs must be subjected to three different types of conditioning:

  • Heat – the SRL must be placed in a heated chamber at 130 degrees F at 85% humidity for two hours
  • Cold – the SRL must be placed in a refrigerated chamber at -40 degrees F for two hours
  • Wet – the SRL (with the lifeline fully extracted) must be sprayed continuously with water at the rate of 18 gallons per hour, or be completely submerged in water for three hours.

After being conditioned (a new SRL may be used for each test), an SRL must be dynamically tested within 90 seconds of being removed from the conditioning chamber and have its performance recorded.

How Does Conditioning Affect The Performance Of An SRL?

ANSI does not explicitly state what to expect from these tests, only that certain performance standards not be exceeded. In other words, if a conditioned SRL does not show any performance difference compared to a non-conditioned (ambient temperature) SRL, it’s just fine. If a heat-conditioned SRL performs slightly better than a cold-conditioned one, as long as it doesn’t exceed ANSI’s requirements, again that is just fine.

OK, OK, I can hear you – “What are the numbers - what are the numbers?!” Here they are: A Class A SRL must arrest a fall within 24” (the same as non-conditioned), with the average arrest force not exceeding 1,575 lbs., and a Class B SRL must arrest a fall within 54” (same as non-conditioned) with the average arrest force not exceeding 1,125 lbs. To make it easy on you, the only acceptable difference between a conditioned and non-conditioned SRL is that the average arrest force is allowed to rise by a maximum of 225 lbs. – that’s it. Of course I could have just told you that at the top, but then you wouldn’t have been able to put the numbers in their proper context.

Think about it, a Class A or B SRL, with a web or cable lifeline can live in the Sahara Desert, your fish tank, or at the South Pole and the only performance difference allowed between it and a dry one at room temperature is a very slight increase in arresting force. And keep in mind this increase in average arrest force is still way below the allowable maximum arrest force of 1,800 lbs! Performance – I should say so!

As a manufacturer of fall prevention products, it’s a challenge to try to stay one step ahead of how products are used in the real world. Just when you think you’ve got your bases covered, something happens somewhere that makes you go back and re-think your processes. Conditioning tests are an example of this, because about the only time an SRL is actually dry and at room temperature is when it is sitting on the shelf at our warehouse or at your local distributor. Any other time, SRLs are constantly being subjected to heat, cold, or moisture. We conduct these tests to give Guardian users the confidence that no matter what the weather, we’ve got you covered, day in day out.

Better yet...want to see one of these conditioning tests in action? Check out the video below from our quality control department who is wrapping up a Cold Conditioning Test!