Ascender Safety 101

       Ascending Rappel Ropes 101

       Autoblock Misuse (ATC-Guide)

       Avalanche Safety

       Belay School - Why Dynamic Matters

       Can A Hot Belay Device Melt My Slings?

       Carabiner Off-Axis and Tri/Quad-Axial Loading

       Choosing the Right Carabiner

       Common Belay Screw-ups

       Connecting Two Slings Together

       Daisy Chain Dangers

       Dangers of Rope Worn Carabiners

       Dangers of Worn Lowering Anchors

       Do Ropes Need to Rest Between Falls

       Draws in a Gym

       Extending a Cam Sling

       Fall Factors Explained

       Full Strength Haul Loops

       Gear Doesn't Last Forever—Crampons

       Gear Doesn't Last Forever—Ice Tool Picks

       Gear Doesn't Last Forever—Slings & Draws

       Girth Hitching a Stopper

       How Sketchy Is a Sharp-Edged Carabiner?

       How Strong are Himalayan Fixed Lines?

       How Strong is the Spinner Leash?

       How To Belay, Part 1

       How To Extend a Rappel Device

       Knot Passing 101

       Rappelling - Climbing's Diciest Business

       Re-Slinging Cams

       Rethinking the Double-Loop Bowline

       Retiring Old Ropes

       Sharpie for Marking the Middle of a Rope?

       Sling Strength In Three Anchor Configurations

       Spectra versus Nylon

       Spotting for Bouldering

       Surviving Bad Weather on El Cap

       The Dangers of Modifying Your Gear

       The Dangers of Short Static Falls

       The Electric Harness Acid Test

       The Skinny on Super Light Ropes

       Top Roping is Not So Safe

       To Screamer Or Not To Screamer

       Via Ferrata

       Weakness of Nose-hooked Carabiners

       What is the Safest Rappel Knot?

       Worn Belay Loops and Retiring a Harness

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Climb Safe: Worn Belay Loops and When to Retire a Harness

By Kolin Powick

The following article is courtesy of Black Diamond Equipment.

  How strong is a belay loop?

From the Black Diamond Harness Instructions: A Black Diamond harness belay loop can withstand 15 kN (3372 lbf) of force.


The CE required testing is a bit difficult to describe, but basically, the belay loop must withstand 15 kN for a period of 3 minutes.

Actual Black Diamond test data: Though our inline batch test rating is 3372 lbf, we regularly see belay loops test to over 6000 lbf, with a historicalaverage of over 5000 lbf. 

** Note: I've tested several other manufacturers' belay loops and they all are in the same ballpark for ultimate strength.


How long should a harness last?
  • Machine wash your harness in warm water on a gentle cycle. Use a mild soap, no bleach. Anytime your harness gets wet, allow it to drip dry away from direct sunlight before storing.
  • Harnesses must not come into contact with corrosive materials such as battery acid, solvents, gasoline or chlorine bleach.
  • Do not allow your harness to be exposed to temperatures above 140° F (60° C) or below -80° F (-62° C).
  • Do not sew, resew, burn or singe loose threads, bleach the webbing, file a buckle, modify, or change a harness in any way.


  • Never store a wet or damp harness.
  • Store all of your gear in a clean and dry environment, out of direct sunlight and away from heat sources.
  • Keep harnesses and other sewn climbing equipment away from gnawing rodents and pets.
  • The nylon in your harness will weaken with age if not stored free from mildew, UV light, temperature extremes or other harmful agents. If a harness has been properly stored for ten years or more, retire it.
  • With normal use and proper care, the life expectancy of your harness is approximately three years, and can be longer or shorter depending on how frequently you use it and on the conditions of its use.

Factors that reduce the lifespan:

  • Falls
  • Abrasion, cuts, wear
  • Heat
  • Sunlight
  • Corrosives


Inspect your harness for signs of damage and wear before and after each use. It is vitally important that your harness be in good condition. A damaged harness must be retired immediately.

Retire a harness immediately if:

There is any kind of rip or hole in the webbing.

The webbing is burnt, singed, or melted.

There are any torn threads, or heavy abrasion to the webbing.

Bar tacks are abraded or showing wear.

One of the buckles is cracked, corroded, has a burr, or is damaged or deformed in any way.

The webbing is faded from exposure to ultraviolet light.

If a harness has been involved in a severe fall, but is not obviously damaged, it still may be ready for retirement. If you have any doubts about the dependability of your harness, retire it and get a new one.

Anytime you retire a piece of gear, destroy it to prevent future use.

**Note: most other climbing gear manufacturer's have similar warnings, instructions, timelines on their products as well.


What could have happened to Todd's belay loop? 

When I first heard of the accident, I was hypothesizing that he just missed clipping into his belay loop—maybe he was tired, with tons of gear, ropes, rack, pack etc all clustered around—and when he clipped his GriGri to his harness, he just missed the belay loop and leaned back for the rappel. I couldn't believe that his belay loop broke—because like I mentioned in the rope breakage report, I am a firm believer of "belay loops just don't break." There must have been some outside circumstances involved. It raises many questions:   

Could Todd's belay loop have been SO worn that it broke under bodyweight?
Could it have been affected by acid?
Could it have been affected by some other chemical (bleach, DEET, etc) that caused it to weaken?
Could it have been so worn, dried out by the sun, or rotten, etc. that it failed under body weight?
Could it have been affected by some other outside circumstances that caused it to fail during rappelling?


Some Unofficial, Incomplete, One-Data Point, For-Curiosity-Only Experiments 

To satisfy my own curiosity I decided to test several belay loops with different levels of wear: cut approx 50% through, cut up to 80% through, cut close to 90% through, two tacks cut, all tacks heavily abraded on a file surface, structural web heavily abraded on a file surface, etc. By no means are these experiments complete or conclusive as there are many variables that were not, but could be looked at like: belay loop construction (2 tacks vs. 4 tacks, protective non-structural layer over top of the tacks), material used (nylon vs. polyester), UV degradation, environmental, wear, etc, etc. Basically, the results were what I was expecting. Belay loops are burly—really burly. To have one fail at body weight loads, or even small shock loads which could happen during rappelling is possible, but the belay loop would have to be SO worn through that it seems very unlikely.

Below are some photos of the different belay loops I tested (before they were pulled to failure) and their tested values.

50% cut through—one side —3480 lbf:

~75% cut through—both sides (not the best photo)—2918 lbf:

~ 90% cut through—one side—777 lbf:   

2 of 4 tacks cut—3970 lbf: 

All tacks heavily abraded across file surface—5280 lbf 

Structural webbing heavily abraded across file surface—4805 lbf: 

All tacks heavily abraded across file surface—5338 lbf:

All tacks heavily abraded across file surface—7429 lbf:


A Final Word 

Is this incident going to cause every climber out there to start wanting two belay loops, or tying a backup webbing belay loop in their current harness or throw their harness away altogether and buy a new one immediately? It shouldn't. Reputable manufacturer's make burly harnesses—bottom line—and don't forget that there are some negatives/concerns about using two belay loops at once in some situations (i.e. tri-axial loading carabiners, etc.)—not good.

Harnesses, and belay loops in particular are super strong for sure, but we can't forget that gear does wear out. Every climber is responsible to know the history of his or her gear and act accordingly. When people ask me about worn gear, or gear that's been dropped, or has undergone a strange or peculiar event, I always have to play the conservative card of "when in doubt, retire it"—because the last thing you want to be thinking of in the back of your mind when you're 20 feet above your last piece of sketchy gear is... "geez, I wonder if that's that biner that I dropped that time," or "I sure hope my harness is in good enough shape to withstand this monster whipper I'm about to take." It's not worth having to worry about—I personally have a hard enough time worrying about trying NOT to fall!

Climb safe,
Kolin Powick


Kolin Powick (KP) is a mechanical engineer hailing from Calgary, Canada. He has over 20 years of experience in the engineering field and served as Black Diamond’s Director of Quality for over 11 years. He is currently their Climbing Category Director. If you have a technical question for KP, please email him at and he will TRY to respond.

To help make more climbers safer climbers, Rock and Ice has teamed up with Black Diamond Equipment to present the information here.

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