TEST RESULTS: Sewn Slings on Wire Stoppers
Thor Lancelot Simon
slings hitched and doubled to wired stoppers. He also tested one
configuration of stopper wires girth-hitched together.
*******************************************************************
Test Report - Sewn Slings on Wire Stoppers - Suicidal or Acceptable
Tom Jones - t...@jrat.com, www.canyoneeringusa.com
Thanks for Black Diamond for providing materials, information and
testing facilities for this test. All conclusions are my own, and
do not represent the opinion of Black Diamond Equipment LTD.
(c) 2002 Nolan Jones. Permission is granted to reproduce only in
it's entirety, including this copyright notice.
Introduction:
The question comes up from time to time - how strong is a sling
thrown through a wired stopper? Some say - really weak - never do
it. Some say - it's not so bad. So I decided to run some tests
and find out.
Black Diamond Wired Stoppers come with 3 sizes of cable: #s 1 and
2 use 1/16" 7x7 galvanized cable; #s 3, 4 and 5 use 3/32" 7x19
galvanized cable; and larger sizes use 1/8" 7x19 galvanized cable.
I concentrated on the larger two sizes. BD was kind enough to make
up samples of just the swaged cables.
Black Diamond Nylon 11/16" or 18mm runners are similar to slings
in common use among climbers. These are probably a little stronger
than average, and were chosen for testing largely because I had a
bunch of new ones from the same batch that I could use. All results
should be scaled down based on the rated strength of the runners
you are using.
WARNING: evaluation of these tests requires experience and judgment.
I do not recommend using slings on wires - but for the expert
climber it MIGHT be a reasonable alternative IN SOME CIRCUMSTANCES.
The Tests:
Of course, we can't test every combination. So here's what I
decided to test:
A. Data on the #2 stopper establishes the base strength of the
1/16" cable. B. Data on the #5 stopper establishes the base
strength of the 3/32" cable. C. Data on the #8 stopper establishes
the base strength of the 1/8" cable. D. Data on Camalot slings
establishes the base strength of the webbing loops.
Base Data:
1/16" cable: Average 724 lbs, Minimum 566 lbs, Rating 450 lbs, N
= 131. 3/32" cable: Average 1747 lbs, Minimum 1409 lbs, Rating
1259 lbs, N = 220. 1/8" cable: Average 2970 lbs, Minimum 2607
lbs, Rating 2248 lbs, N=190. Slings: Average 5781 lbs, Minimum
5393 lbs, Rating 4946 lbs, N=236.
But, we're not going to be real sophisticated here, we'll just use
the average.
1/6" cable = 724 lbs. 3/32" cable = 1747 lbs. 1/8" cable = 2248
lbs. Sling = 5781.
New Test Data - all tests use 4 samples. All strengths in pounds.
T1: Test actual batch of slings.
Average = 5880. Minimum = 5733.
Conclusion: this batch of slings a little stronger than average.
T2: Test slings, girth hitched together (as they normally are in
the field), not neatly dressed.
Average = 4363. Minimum = 4084.
Conclusion: girth hitching sling to sling loses 26% of the sling
strength. Given the high initial strength, the hitched system is
still strong enough for most climbing uses.
T3: 1/16" cable with sling girth hitched to it.
Average = 936.5. Minimum = 911
Conclusion: compared to 1/16" cable average of 724 lbs - Sling is
stronger when girth hitched to sling than when run over the head
of a tiny stopper.
T4: 3/32" cable with sling girth hitched to it.
Average = 1301.5. Minimum = 1269.
Conclusion: compare to 3/32" cable average of 1747 lbs. Loss of
strength of 26% on the cable.
T5: 1/8" cable with sling girth hitched to it.
Average = 1709.0 Minimum = 1624.
Conclusion: compare to 1/8" cable average of 2248 lbs. Loss of
strength of 28%.
T6: 1/8" cable with sling doubled through it (rather than girth
hitched).
Average = 3211. Minimum = 3054.
Conclusion: compare to 1/8" cable average of 2248 lbs. No loss
of strength.
T7: 3/32" cable girth hitched with 3/32" cable (stopper to stopper
extension).
Average = 1520. Minimum = 1439.
Conclusion: compare to 3/32" cable 1747, loss of strength of 13%
- better than the sling.
Comments: The data is screwed up a little bit because the actual
stoppers are tested with the aluminum stopper at the top and a 10mm
pin at the bottom. These commonly break at the top, where the
cable folds tightly going into the stopper. Thus, in these tests,
we can achieve "stronger than average results" because we are
running the tests differently.
Overall conclusion:
Yes and No.
1/16" cable (really small stoppers)
You probably would not think of tossing a sling through these,
because the placement and the cable are so small and weak to begin
with. Looks like the sling does not make it any worse, but this
is of little utility, since this is an aid piece anyway. Not strong
enough to rappel off of.
3/32" cable (small stoppers 4, 5 and 6)
I think these are usually considered pretty strong, but not truck.
Girth Hitching the sling through gives you significant loss of
strength, to down below the rating on the #5 Stopper. May be OK
for rappelling and low-impact falls, but not for general use.
1/8" cable (large stoppers)
These are usually considered truck. Tossing the sling through
results in a strength of 1709 lbs (loss of 28%). Sketchy still,
even on the large size. OK for rappelling and low-impact circumstances,
but not for general use.
Girth Hitch vs. Doubling the sling through:
Doubling through WINS big time. Yes, it takes twice as much sling,
but it is definitely significantly stronger.
Wire Cable hitched with Wire Cable (Stopper to Stopper extension)
Stronger than the sling, but not that strong. Makes for a stiff
unit, negating what is often the prime reason for extending the
piece in the first place.
Conclusive Overall Conclusions:
Girth Hitching a NYLON sling through reasonable size Stoppers is
OK for low-strength operations, but should be treated with caution.
Doubling the sling through, especially on the smaller sizes, is
acceptable. Extending with cables suffers from some of the same
problems, though to a lesser degree.
Spectra Slings - No comment, not tested.
And of course, everyone will draw the line differently. Protecting
a 60' runout and no biners to spare? Sure, it's better than nothing,
but I'd try to double the sling through at the very least. For
setting a rappel? Acceptable I guess, in the larger sizes, but
repeated use might eventually cut the webbing.
Using smaller webbing than the BD 18mm nylon slings? Exercise more
caution.
That's my story, I'm a stickin' to it.
(signed) Tom Jones aka Jrat aka Ratagonius Utahness
--
Thor Lancelot Simon t...@rek.tjls.com
But as he knew no bad language, he had called him all the names of common
objects that he could think of, and had screamed: "You lamp! You towel! You
plate!" and so on. --Sigmund Freud
Bill Zaumen
Thanks for posting the results. It seems to match what I posted
on the subject (and that got a lot of static for) to the effect that
using slings directly on wired nuts is not suicidal (although
using a runner directly on a wired nut is something I'd
do only under other unusual circumstances such as running low on
gear).
In terms of the question someone posted about cases where a biner
might be cross loaded due to resting against an edge or
bulge, it sounds like running a doubled sling around the cable is
a reasonable choice unless the edge is sharp.
Also, keep in mind that Tom's tests and conclusions compared the
strength of the sling to the full strength of the cable. If you
have a placement that is not so good to begin with, looping a sling
through the cable may not make any difference at all, due to the
protection pulling out before the sling is loaded enough to break.
> Tom Jones - t...@jrat.com, www.canyoneeringusa.com
>
> Thanks for Black Diamond for providing materials, information and
> testing facilities for this test. All conclusions are my own, and
> do not represent the opinion of Black Diamond Equipment LTD.
<snip>
> Conclusive Overall Conclusions:
>
> Girth Hitching a NYLON sling through reasonable size Stoppers is
> OK for low-strength operations, but should be treated with caution.
> Doubling the sling through, especially on the smaller sizes, is
> acceptable. Extending with cables suffers from some of the same
> problems, though to a lesser degree.
>
> Spectra Slings - No comment, not tested.
>
> And of course, everyone will draw the line differently. Protecting
> a 60' runout and no biners to spare? Sure, it's better than nothing,
> but I'd try to double the sling through at the very least. ...
Bill
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Mad Dog
>Thanks for posting the results. It seems to match what I posted
>on the subject (and that got a lot of static for) to the effect that
>using slings directly on wired nuts is not suicidal (although
>using a runner directly on a wired nut is something I'd
>do only under other unusual circumstances such as running low on
>gear).
We can only hope you find yourself in this situation often, if only to equalize
your own position with that you wish often on others.
>Also, keep in mind that Tom's tests and conclusions compared the
>strength of the sling to the full strength of the cable. If you
>have a placement that is not so good to begin with, looping a sling
>through the cable may not make any difference at all, due to the
>protection pulling out before the sling is loaded enough to break.
"Shit plus shit equals shit" appears to be your motto here, and who are we to
argue with such a qualified expert in the field of shit? You're certainly full
enough of it!
Actually, some of us read the entire post and noticed a key part you chose to
snip, that being:
>>Black Diamond Nylon 11/16" or 18mm runners are similar to slings
>>in common use among climbers. These are probably a little stronger
>>than average, and were chosen for testing largely because I had a
>>bunch of new ones from the same batch that I could use. All results
>>should be scaled down based on the rated strength of the runners
>>you are using.
For those with 5mm perlon slings in their pockets, go directly to the Group W
bench.
>>WARNING: evaluation of these tests requires experience and judgment.
Ill, go directly to the Group D bench.
>>I do not recommend using slings on wires - but for the expert
>>climber it MIGHT be a reasonable alternative IN SOME CIRCUMSTANCES.
That's a fairly clear conclusion, and one you chose not to include in your
summary, Ill... Why do you suppose that is?
Bill Zaumen
> >>I do not recommend using slings on wires - but for the expert
> >>climber it MIGHT be a reasonable alternative IN SOME CIRCUMSTANCES.
>
> That's a fairly clear conclusion, and one you chose not to include in your
> summary, Ill... Why do you suppose that is?
Because the quantitative results are what is interesting, the whining
of certain newsgroup children not withstanding. BTW, if you had
bothered to read what I had posted, you would have understood that the
usages I described would fit the "some circumstances" criteria.
Frank Stock
> Tom Jones asked me to post the following results of his testing of sewn
> slings hitched and doubled to wired stoppers. He also tested one
> configuration of stopper wires girth-hitched together.
>
Before this gets drug down an enlightened discussion between Bill and
Mad Dog, let me remember to thank you for posting this and taking the
time to do it. Interesting stuff.
Cheers,
Frank
Mad Dog
>Mad Dog wrote:
>>>>I do not recommend using slings on wires - but for the expert
>>>>climber it MIGHT be a reasonable alternative IN SOME CIRCUMSTANCES.
Re-read the above, Ill. He said "expert". You clearly do not qualify, seeing
as how you have trouble with simple concepts such as anchor redundancy,
acceptable prussic cord size, applicability of climbing equipment for a given
situation, etc. So Tom's not supporting your claims about girth hitching wires,
because that domain is well beyond your knowledge level. Remember, you
advocated keeping 5 or 6mm nylon prussics in your pockets for times when you run
short on gear. Do you girth hitch wires with your 5mm perlon when you run short
of slings and biners?
>> That's a fairly clear conclusion, and one you chose not to include in your
>> summary, Ill... Why do you suppose that is?
>Because the quantitative results are what is interesting, the whining
>of certain newsgroup children not withstanding.
And if you knew experimental design, then you would have noticed that Tom's work
had a glaring omission. Sure, his data illuminated certain aspects of girth
hitching or doubling web over a wire and we can learn from the trends, but for a
hyper-statistical wannabe such as yourself, I'd think that, if you were unbiased
and in search of the truth, then that omission would have been mentioned. But
you wouldn't want to do anything to weaken your stance, would you? I've seen
attitudes like your in science for way too long - as if to say: "I'll use the
data that supports my hypothesis and bury my head in the sand if anything
contradictory shows up."
What glaring omission? Tom mentioned that his choice of runner was on the high
side strength-wise and that was an important caveat. But to bring this type of
study into the real world, one would need to test a large variety of runners, in
order to represent what real climbers have on their racks. For example, I often
see people using 9/16" nylon that is NOT supertube. The loop strength is 900
pounds. Now, tell me what you think the trend would be if Tom's test involved a
few pieces of 5 to 10 year old non-supertube 9/16 nylon that had been abraded
repeatedly on desert towers and in valley chimneys? If you want to talk about
interesting quantitative results, then wouldn't you want all of the real world
data? Wouldn't you want to see results for Spectra slings?
>BTW, if you had bothered to read what I had posted, you would have understood
>that the usages I described would fit the "some circumstances" criteria.
With regards to reading your drivel, "bothered" is an appropriate descriptor.
It's just too bad you didn't take the time to read Tom's conclusions and to
realize that your abilities with regards to climbing safety do not even come
close to placing you in the expert category. The 5.7 climber can't tell the
difference between a 5.11 and an 11+ offwidth and you sure as shit cannot
determine when a girth-hitched wire is safe.
Michael Boos
> Zaumoron drones on...
>
>> Mad Dog wrote:
>>
<lots of (interesting) technicalities and especially not so unoersonal
remarks snipped>
go on, guys, interesting wrestling with words in an international
environment - perhaps you could write under your real names, or don't you
dare to? ;-((
--
*********************
L. Michael Boos
CH-8001 Zuerich
*********************
to e-mail remove 4 dots from left to right
Dr. Schitt
hitched slings to wires in certain circumstances, such as when no better
option presents itself.
Thor Lancelot Simon
Of course, since it found that a *doubled* sling through a wire is far
stronger, there would appear to always be a better option. That was
the conclusion that really stood out, to my mind -- that given a
large-diameter wire and a doubled sling, this wasn't as stupid as I'd
thought it was.
On the other hand, the data sure looks to me like girth-hitching through
wires is really, really dumb if you're doing it for any purpose other
than bodyweight aid.
Jason Lucero
have a lot of time on you hands. I got some good laughs from the
"...might be reasonable in some circumstances." and the "...If you
have a placement that is not so good to begin with..." stuff, but
largely you guys are not being very entertaining.
"We've got pockets of persistent poverty in our society, which I
refuse to declare defeat-I mean, I refuse to allow them to continue on.
And so one of the things that we're trying to do is to encourage a
faith-based initiative to spread its wings all across America, to be
able to capture this great compassionate spirit." -G. W. Bush
How about some stuff like that?
Jason, so what if the pro don't hold, trad climbers bounce, Lucero
Mike
sheath around the wire at the end? I assume these will be less prone to
breaking the sling? I was considering buying these to use during alpine
climbing, to save the weight of a biner at each stopper. I was also thinking
of dipping the clip end of my current BD stopper's in that "tool dip" stuff
to cover the wire that would contact the sling. Any thoughts?
"Thor Lancelot Simon" <t...@panix.com> wrote in message
news:a7omie$sit$1...@panix1.panix.com...
Hal Murray
>sheath around the wire at the end? I assume these will be less prone to
>breaking the sling? I was considering buying these to use during alpine
>climbing, to save the weight of a biner at each stopper. I was also thinking
>of dipping the clip end of my current BD stopper's in that "tool dip" stuff
>to cover the wire that would contact the sling. Any thoughts?
I'd worry that the plastic, especially the tool-grip stuff, wouldn't be
very strong and would simply get squished out of the way as soon
as you put a serious load on it.
Should be an easy experiment to do, even without fancy equipment.
Push the wire up through the stopper so you can get a biner on
it. Attach it to a post, bumber, tree, whatever. Attach sling
to other end of stopper. Attach old junk rope. Get several strong
people to play tug-of-war. (Or use a car/truck.)
Or just hang it from a tree branch. If you bounce real hard you
can get 2x your body weight. (maybe 3x?)
Disassemble and inspect.
--
These are my opinions, not necessarily my employer's. I hate spam.
Madbolter
> Interesting. How about the new Metolious stoppers which have the plastic
> sheath around the wire at the end? I assume these will be less prone to
> breaking the sling? I was considering buying these to use during alpine
> climbing, to save the weight of a biner at each stopper. I was also thinking
> of dipping the clip end of my current BD stopper's in that "tool dip" stuff
> to cover the wire that would contact the sling. Any thoughts?
PlastiDip-ping wired stoppers is not really the best idea. Especially
if you're planning on getting the gear wet often (as in ice climbing/
mountaineering). Apparently water can wick down inside the cable during
the climb and eventually rust out the cable where you can't visually
inspect it (under the PlastiDip). I'm guessing that the plastic sheaths
used by Metolius and HB allow better airflow (and thus dry out), plus
they can be removed if necessary, unlike PlastiDip.
On the other hand this could just be another bumblie myth(take).
-Rex Pieper
Jason Lucero
Jason
In article <3CA35165...@REMOVETHISbigwall.com>, Madbolter
Dwight Haymes
Jason Lucero <J...@samuraisurfer.nospam.com> wrote in message
news:280320021819539924%J...@samuraisurfer.nospam.com...
> Does stainless steel rust?
Yes. 302/304 Stainless can rust and the conditions Rex described are
accurate.
Dwight
Jason Lucero
anyways, I just don't see what it really adds, but my experience is
limited. Does anyone see this stuff as a benefit?
Jason
In article <qEQo8.23567$8r.1...@nwrddc01.gnilink.net>, Dwight Haymes
Madbolter
> Thats good to know. I don't like the plastic-dipped idea on pro
> anyways, I just don't see what it really adds, but my experience is
> limited. Does anyone see this stuff as a benefit?
If there were any benefit you would see the major gear manufacturers
doing it and touting it as a benefit in all their ads. Camp nuts were
PlastiDip-ed once upon a time and IIRC discontinued the practice soon
thereafter due to the reasons I mentioned earlier.
The plastic tubing on HB/Metolius stoppers is only a visual aid for
quick sizing identification. I doubt these companies would ever
recommend/endorse slinging wired nuts without a carabiner, regardless
of the recent test numbers.
If you want to retro-color-code your stuff, several colors of spray
paint will do the trick far better/safer than PlastiDip. Just beware
of using the same color your partner uses to mark all of his gear or
risk certain sizes of your gear migrating to his rack.
-Rex Pieper
Brent Ware
> If you want to retro-color-code your stuff, several colors of spray
> paint will do the trick far better/safer than PlastiDip. Just beware
^^^^^^
> of using the same color your partner uses to mark all of his gear or
> risk certain sizes of your gear migrating to his rack.
Is that a veiled slur?
In any case, I no longer mark any of my gear, on the theory that if it
doesn't have any markings, it's mine. My rack grows every trip.
-bware
Madbolter
> Madbolter <r...@REMOVETHISbigwall.com> writes:
>>If you want to retro-color-code your stuff, several colors of spray
>>paint will do the trick far better/safer than PlastiDip. Just beware
>>
> ^^^^^^
>
>>of using the same color your partner uses to mark all of his gear or
>>risk certain sizes of your gear migrating to his rack.
>>
>
> Is that a veiled slur?
Completely. err coincidental. Whatsamatter? You feeling guilty about
something? (Out, out damn spot)
> In any case, I no longer mark any of my gear, on the theory that if it
> doesn't have any markings, it's mine. My rack grows every trip.
>
> -bware
Which is why we often climb on your gear! I'm no fool.
-Rex Pieper
Bill Zaumen
<r...@REMOVETHISbigwall.com> wrote:
> > In any case, I no longer mark any of my gear, on the theory that if it
> > doesn't have any markings, it's mine. My rack grows every trip.
> >
> > -bware
>
>
> Which is why we often climb on your gear! I'm no fool.
I was once sorting gear with a friend and asked, "Is this your biner?"
and he said, "does it have a gate on it?"
Bill
Freeze
> In article <3CA576DC...@REMOVETHISbigwall.com>, Madbolter
> <r...@REMOVETHISbigwall.com> wrote:
>
>
> > > In any case, I no longer mark any of my gear, on the theory that if it
> > > doesn't have any markings, it's mine. My rack grows every trip.
> > >
> > > -bware
> >
> >
> > Which is why we often climb on your gear! I'm no fool.
>
> I was once sorting gear with a friend and asked, "Is this your biner?"
> and he said, "does it have a gate on it?"
>
> Bill
The plastic coating is for size identifaiction only. It serves no
structual purpose. The thickness of the cable is very hard on slings
as it is such a small diameter, that is what primarly cuts slings when
they are loaded across the cable not the texture of the surface of the
wire.