QC Lab: From the Archives

Since we launched the Black Diamond Journal in 2009, we've had lots of requests for old QC Lab case studies from our Director of Global Quality, Kolin Powick. Ok, ok, we've heard you. Below are a few of KP's in-depth technical reports from our QC Lab archives.

 

"Is my rope still OK to use if I accidentally peed on it?"  12/18/06

Breaking Fixed Draws and Biners from a Dark, Dreary Cave Route 8/16/06

Rope Breaks in a Low-Impact Fall at Climbing Gym - Investigation  8/8/06

Testing More Old Beat-Up Slings and Carabiners 1/9/06

Testing Old Gear from the VRG 12/2/05

---

 

December 18, 2006: "Is my rope still OK to use if I accidentally peed on it?"

 

It's almost disturbing how many emails I get with the almost identical: "Uhhh, hmmmm, I kinda peed on my rope, do you think it's still ok?," or "A dog peed on my rope at the crag, should I retire it?," or "My girlfriend peed on my rope, is it still ok to use?"

I hate to sound like a broken record, but when this sort of thing happens, no one can be exactly sure what effect it had on your rope or equipment. I always have to play the conservative card and say, "If in doubt, retire it."

Other than wondering what actually is going on out in the field with all of these people peeing on each other's ropes, I wondered what kind of affect does it really have. No, I didn't go pee on a rope of mine and test it, but as "luck" would have it, I got an email from a person something to the effect of:

"My cat peed on my brand new 9.1 mm, it sat there for over a week, when I got home to discover this I washed it several times in baking soda to get rid of the smell, and I have two questions for you:

• Is the rope ok to use?
• What kind of hat should I make out of my cat? Note: he really did ask this...

I had the guy send the now non-stinky rope in and we performed some tests on it.

So again, of course, by no means are these experiments conclusive-just some interesting information if you happen to have a cat pee on your brand new rope and then wash it in baking soda three times.

The Tests

We performed all tests on the 'Cat Pee' rope alongside a baseline test of a brand new 9.1 mm of the same brand-so that we could compare relative results.

Static Tensile Tests

• Full Strength-Pulled five samples of each rope in tension in the tensile test machine-ropes wrapped around drum jigs to force the failure mode to the single strand.
• Strength over a Carabiner-Pulled two samples of each rope in tension in the tensile test machine-over a carabiner-using figure 8 knots on each end.

Drop Tower Tests (note: these tests are not in any way even close to the UiAA drop tests)

• 4 ft length of rope-figure 8 knots in each end-factor 1.35 fall-over a carabiner
• 8 ft length of rope-figure 8 knots on each end-factor 1.2 fall-over a carabiner
• 4 ft length of rope-figure 8 knots on each end-factor 2 fall-direct onto anchor
• 8 ft length of rope-figure 8 knots on each end-factor 2 fall-direct onto anchor

The Results

Tensile Tests

In all cases the failure mode was the rope breaking at the fixture. So this isn't a totally accurate test as the desired mode would be the sample breaking in the middle, however, for our purposes it does give us a relative comparison to some extent.

• Full Strength Test-The 'Cat Pee' rope averaged approximated 94% of full strength of a brand new rope.

~Full Strength
Joker 9.1		Joker w/ Cat Pee
	Strength (lbf)		Strength (lbf)
1	4739	1	4329
2	4361	2	4058
3	4547	3	4362
4	4421	4	4373
5	4671	5	4295
		6	4285
avg.	4547.8	avg.	4283.7
% full	100	% full	94.2

• Over a carabiner-The 'Cat Pee' rope averaged approximately 95% of the strength of the brand new rope.

Strength Over Carabiner
Joker 9.1		Joker w/ Cat Pee
	Strength (lbf)		Strength (lbf)
1	6406	1	6014
2	6324	2	6081
avg.	6365.0	avg.	6047.5
% full	100	% full	95.0

 

Drop Tower Tests

• 4 ft length of rope-figure 8 knots in each end-factor 1.35 fall-over a carabiner.

New Joker 9.1 mm		"Cat Pee 9.1 mm"
# Falls Held	Max Load Seen	# Falls Held	Max Load Seen
14	3968	9	3982

 

Factor ~ 1.35 over a BD Airlock2
Joker 9.1		Joker w/ Cat Pee
Drop	Max Force (lbf)	Drop	Max Force (lbf)
1	1411	1	1680
2	2264	2	2402
3	2699	3	2972
4	2968	4	3265
5	3189	5	3446
6	3336	6	3681
7	3458	7	3748
8	3572	8	3895
9	3570	9	3982
10	3698	10	3239 X
11	3765
12	3870
13	3912
14	3968
15	3470 X

• 8 ft length of rope-figure 8 knots on each end-factor 1.2 fall-over a carabiner.

New Joker 9.1 mm		"Cat Pee 9.1 mm"
# Falls Held	Max Load Seen	# Falls Held	Max Load Seen
6	4148	5	4045

 

Factor ~ 1.2 over a Omega Steel
Joker 9.1		Joker w/ Cat Pee
Drop	Max Force (lbf)	Drop	Max Force (lbf)
1	2189	1	2279
2	3007	2	3081
3	3465	3	3536
4	3763	4	3878
5	3979	5	4045
6	4148	6	3592 X
7	4029 X

• 4 ft length of rope-figure 8 knots on each end-factor 2 fall-direct onto anchor.

New Joker 9.1 mm		"Cat Pee 9.1 mm"
# Falls Held	Max Load Seen	# Falls Held	Max Load Seen
5	2759	3	2357

 

Factor ~ 2 w/ Figure 8 in Both Ends
Joker 9.1		Joker w/ Cat Pee
Drop	Max Force (lbf)	Drop	Max Force (lbf)
1	1248	1	1364
2	1891	2	2041
3	2260	3	2357
4	2488	4	No Drop X
5	2759
6	2316 X

• 8 ft length of rope-figure 8 knots on each end-factor 2 fall-direct onto anchor.

New Joker 9.1 mm		"Cat Pee 9.1 mm"
# Falls Held	Max Load Seen	# Falls Held	Max Load Seen
3	2583	2	2687

 

Joker 9.1		Joker w/ Cat Pee
Drop	Max Force (lbf)	Drop	Max Force (lbf)
1	1708	1	1754
2	2380	2	2470
3	2583	3	2687 X
4	No Drop X

Observations

• The "Cat Pee" rope was approximately 95% of the static strength of a new rope.
• You can see during the first drop tower test that the "Cat Pee" rope saw higher loads faster.  This means that it did not have equal elastic properties to the brand new rope.
• The "Cat Pee" rope withheld slightly fewer falls in all other drop tower tests.
  

Further Information

I contacted Pit Schubert who is an expert in climbing gear accidents and testing and asked if he had done any tests regarding urine and ropes.  His response is below:

"I made test with ropes and human urine-I put rope samples in a pot with urine over night and sent them to the university of Stuttgart for testing according to EN 892-the result: reduction of the number of falls 30%-after this I had the idea, that a rope in a pot of urine over night is not realistic-so I put only a lot of urine drops on the rope samples, but morning urine (because morning urine is stronger than day urine)-the result: reduction of the number of falls 13%.

I hope this is helpful for you.

I published this in my book 'Sicherheit und Risiko in Fels und Eis', Volume 2, (only in German, translated in Spain, Czech, Netherlands and Japanese language, but not in English—sorry).

Kind regards,

Pit"

Conclusions

It would appear that urine on a rope DOES affect the ultimate strength and the number of falls held. The extent to which it affects the properties of a rope and how it would relate to real world climbing situations is variable, undetermined and ultimately unknown given the many factors specific to each situation (amount of urine, age of rope when exposed, how long exposed to urine, type of loading scenario, etc). It also appears that either the urine alone and/or the washing in baking soda affected the elastic properties of the rope, making it less dynamic and causing increased force on the anchor during the drop tests. Though the results seen here don't necessarily show that urine on a rope can be catastrophic, it is always ultimately up to the climber him/herself to make the decision regarding the use of their own equipment, especially after peculiar and sometimes unknown circumstances.

A Final Word

Even if the testing here isn't conclusive to show possible catastrophic circumstances, don't pee on your rope. It's kinda gross.

Be safe,

KP

 

---

 

August 16, 2006 - Breaking Fixed Draws and Biners from a Dark, Dreary Cave Route

Lately I've had some people wondering how strong their old gear is-stuff that's usually been fixed on some 'proj' for some unknown amount of time-and rather than leaving it up indefinitely for some unsuspecting sucker to take the big ride, they remove it and if/when I get around to it we'll break it to see if we can learn anything.

Recently someone stripped their old gear off the route Burning in the Hell Cave at American Fork, Utah. Now talk about a hole. That place sees more seapage, water, cold and dark than you could imagine, but even still does manage to see some sunlight. These were classic beat-up looking draws. Super crusty webbing, corrosion and oxidation on the biners, the full meal deal...

My guess is as usual: the biners are much stronger than you would think given how they look, but the webbing which appeared to be dried up and even somewhat brittle was my concern.

Remember:

• The CE requirement for new slings is 22 kN
• Biners such as these must maintain 20 kN in closed gate, though all of these were rated stronger (22-26 kN)
• Typical sport falls are in the 2-5 kN range...
• We tested these in the tensile testing machine AS quickdraws-then after the webbing was broke, we tested the biners individually.

The Results

The biners all met their rated strength. It's nice to know that in most cases even old beat-up looking biners that have been left outside for months are still burly strong. The risk with these usually isn't the strength of the biner in closed gate, rather: sharp edges of worn biners causing a rope to cut (corroded, oxidized biners having such crappy gate action that the gate won't close). I know, I've climbed on draws with 'fixed' routes at Rifle, the VRG, the RED, Maple, etc and you clip your rope in then have to manually close the gate... not sweet.

All of the webbing failed to meet 22 kN. The range was as low as 13 kN and as high as 20 kN (the average value was 17.6 kN).

Conclusion

Though not dangerously weak, the nylon webbing from these quickdraws was definitely weaker than when new due to exposure to the elements, use, wear, etc. The biners were all still burly in closed-gate testing. The problem with mank gear like this is ensuring that the gate is closed... more on this in a later installment.

Moral of the Story

Now people have been climbing on these exact draws for who knows how long, without incident-and chances are they could have stayed up there for much longer and been fine, but you must use your common sense and don't climb on fixed gear that you think is suspect, and don't leave suspect gear on routes-you're not doing anyone any favors. Don't be shy to replace old crappy gear-it may cost you a bit, but it's good karma, plus you'll be doing yourself a favor on that redpoint burn-the last thing you want to be thinking is "I sure hope that old manky quickdraw at the crux is still strong enough in case I whip..."

Out for now,

KP

 

---

 

August 8, 2006 - Rope Breaks in Low-impact Fall at a Climbing Gym-Investigation

 

Hey,

You may have heard about a climbing rope that broke at a climbing gym in California back in May. Luckily no one was hurt. I was asked to look into the incident. I inspected the rope, went to the gym and inspected the route and all other equipment and even sent the rope out to labs for chemical analysis. Click HERE for the full blown 11-page .pdf report-and don't just skip to the end.

Climb safe,

KP

 

---

January 9, 2006 - Testing More Beat-up Slings and Carabiners

 

 

 

 

This weekend I swapped out about 45 draws at the VRG. We broke all the slings, and a few of the biners.

Again-biners aren't usually the problem-even though the bolt end biner gets all nicked and gouged up-they are still usually plenty burly. The ones we broke today were a bit surprising however. While most current style biners all still broke above 18kN, there were a few OLD school biners (made from smaller diameter rod stock) that broke at 8kN-and the breakage didn't even occur where it was nicked from the bolt hanger. Freaky.

The rope end biners, even when worn, are still usually full strength-the problem is usually a sharp edge forming and possibly "sheathing" your rope-a bummer-and horrifying I'm sure. Another obvious problem with fixed draws is the gate action can get very poor-possibly resulting an open gate loading scenario-not ideal... Rope end biners all broke above 20 kN.The "dogbones" are the part I'm usually more worried about. When new, dogbones need to meet 22 kN. In the previous emails we've seen some break as low as 5,7 and 9 kN-much lower than I would have thought-and kind of scary actually. Based on what I've seen in some earlier tests, as well as some reading, I was kind of thinking that maybe Nylon fared better than Spectra (with respect to weathering)-I'm still looking into this, and will let you know-but based on the 45 dogbones broke today-there can be no hard fast conclusion regarding whether Nylon or Spectra is best to leave on a fixed route.

Out of the 45 dogbones broke today-there were values ranging from 23.5 kN all the way down to 8 kN. Most are in the 12 kn-17 kN zone-still safe-but definitely much weaker than when new.

BD spectra dogbones (green/white checkered) - 9.7, 10.3, 11.6 kN
BD Nylon - 13.5, 14.5, 18.9 blah blah blah up to 23.5 kN
Metolius Nylon - 17-18 kN
Petzl Nylon - 8.1, 9.4, 10, 11, 12... up to 15 kN
misc Nylon - 11 up to 17 kN

Note: All of the quickdraws that I've been replacing are with Spectra dogbones. If I determine that Nylon does better in the weather (which it doesn't really appear to based on this data)-then I will swap them out with Nylon webbing next year.

 

---

 

December 2, 2005 - Testing Old Gear from the VRG

FYI-sling ratings are 22 kN

Minimum carabiner ratings are 20 kN

Typical sport climbing falls are in the 2-5 kN range.

I pulled a bunch of mank gear from some routes last weekend at the gorge (DCMD, Fall of Mouse). I'm never really concerned about the biners from a strength standpoint- more from getting a sharp edge and "sheathing" the rope. The biners I tested were WORKED, but all values were still above the original product ratings (all over 24 kN).

The slings were very sun bleached and dried out-I'm pretty sure some have been up there for 3, 4, or even more years.

The results were:

16 kN
11 kN
11 kN
5 kN

Obviously getting well into sketchy land.

The morale of the story from KP's point of view-carabiners and slings are way burlier than people think, ie. leaving a route fixed for a while isn't the end of the world. As I said, the biners developing sharp edges is usually my big concern. But it is important to remember that it IS possible for slings and carabiners to break-slings from being excessively sun bleached and dry and/or being worn from excessive rubbing on the rock.
When you hear of biners breaking in the field it's usually either open gate failure or the nose hook getting caught on the bolt hanger, etc.

it's always a good thing to replace a draw on a fixed route that you're sketched about-the last thing you want to be worrying about when you're 10 ft above your last bolt and sketching out on pimp holds is "I hope that draw will hold if I pitch" (and also, it's good sending-karma to replace sketchy fixed gear).

 

 

 

Tags for this Article:
qc-lab, climb, qclab

Recent Talk (1)

• BD crew
  2 May 2013, 3:16PM

  @brian - these are typical peak loads that the bolt or quickdraw would
  see in a typical sport climbing fall.

• Brian
  29 Apr 2013, 10:02PM

  Thanks for the awesome info! I was curious when you say, "Typical sport climbing falls are in the 2-5 kN range." is this before or after the dynamic affects of the rope? As in, is this the starting force and then it is further reduced by dynamic stretching? Or is this after all factors are considered?
  
  Thanks,
  Brian

• Andrew
  7 Dec 2010, 2:02PM

  Do I need to 'rest' my nylon QD sling between falls like I do my rope? If I keep falling on one QD do I need to rest the sling or can I just switch (ends of) ropes and keep falling?

• Jay
  7 Nov 2010, 11:08AM

  This QC lab section is great, I'm glad BD brought it back. I found the Rope Break investigation particularly fascinating.

Talk!

Share your comments with us.

Name

Email

Comment COMMENT

SUBMIT