dangerous gear setups I won't use

[cj001f]

Oh Grand My Schlong is Longer than yours because I have a PHD completely unrelated to the topic at hand - and am therefore superior to someone who's done quite a bit of practical measurements.

I hesitate to point out that - the failure mechanism for a sewn sling is much different than a girth hitch.

On a sewn sling the force will be distributed equally across the sling from the wire.

With a girth hitch the force will be directed onto a smaller area of the sling -(because the girth hitch will not lie flat - and the load will be directed across the axis of the sling)

Think about it. And no it probably doesn't matter that much for most situations. But it will for some.

Carl

[ 03-21-2002: Message edited by: cj001f ]

[Dru]

quote:

---

Originally posted by chucK:

Static or dynamic rope?

I'm sure there's a geek or two on rec.climbing who would convert it to KN for you.

---

Well it depends on the specific gravity of the rocks,and how densely they were packed, see....

But it was a chunk of old dynamic rope.

And I bet it depends a lot on how well you paste that head in, too.

[hakioawa]

1mm of tape could make a difference. Wire in made of on lots of little strands, maybe 1/10 of a mm. So the radius of curvature is something like 11x larger with 1mm or tape. Its the radius of curvature that is the issue.

[chucK]

quote:

---

Originally posted by cj001f:

Oh Grand My Schlong is Longer than yours because I have a PHD completely unrelated to the topic at hand - and am therefore superior to someone who's done quite a bit of practical measurements.

---

Dude! I think that is his point. The part about "quite a bit of practical measurements" that is. There are tons of posters who posted that it is obviously stupid to girth hitch a wire but it is doubtful that many have done any practical measurements. I have not. If anybody else has, they have not posted their findings. Dru is the only one so far, but I didn't see anything yet that talked about girth hitches through wires? AFAICT Dru's experiments blew out a copperhead.

Who here has done quite a bit of practical measurements? IF so, speak out! Present your results.

[ 03-21-2002: Message edited by: chucK ]

[Dru]

If somebody tells you that you can jump off a 50m cliff and land safely, would you trust them and do it, or think "Dude, sounds sketchy" and not do it, or test it a few times with a bag of rocks before you realized it was sketchy?

[chucK]

If somebody tells you that you can jump off a 3m cliff and land safely, would you trust them and do it, or think "Dude, sounds sketchy" and not do it, or test it a few times with a bag of rocks before you realized it was sketchy?

[ 03-21-2002: Message edited by: chucK ]

[erik]

i dont even know what the stuff is for...but?!?!?!?!?!?!!?!

[ 03-22-2002: Message edited by: erik ]

[HeadSpace]

Climbing is a test of one's will. Testing your pro(falling on it!)is failure. Place pro like you know how and climb like you know how. All the technobable in the world won't help your onsight. Believe in what you say. Bring on the HEAT!

[chucK]

Psychobabble is cool though

[freeclimb9]

bummer about the Hepatitis.

[rbw1966]

From rec.climbing:Test Report - Sewn Slings on Wire Stoppers - Suicidal or Acceptable

Tom Jones - tom@jrat.com, www.canyoneeringusa.com

Thanks for Black Diamond for providing materials, information andtesting facilities for this test. All conclusions are my own, anddo not represent the opinion of Black Diamond Equipment LTD.

© 2002 Nolan Jones. Permission is granted to reproduce only init's entirety, including this copyright notice.

Introduction:

The question comes up from time to time - how strong is a slingthrown through a wired stopper? Some say - really weak - never doit. Some say - it's not so bad. So I decided to run some testsand find out.

Black Diamond Wired Stoppers come with 3 sizes of cable: #s 1 and2 use 1/16" 7x7 galvanized cable; #s 3, 4 and 5 use 3/32" 7x19galvanized cable; and larger sizes use 1/8" 7x19 galvanized cable.I concentrated on the larger two sizes. BD was kind enough to makeup samples of just the swaged cables.

Black Diamond Nylon 11/16" or 18mm runners are similar to slingsin common use among climbers. These are probably a little strongerthan average, and were chosen for testing largely because I had abunch of new ones from the same batch that I could use. All resultsshould be scaled down based on the rated strength of the runnersyou are using.

WARNING: evaluation of these tests requires experience and judgment.I do not recommend using slings on wires - but for the expertclimber it MIGHT be a reasonable alternative IN SOME CIRCUMSTANCES.

The Tests:

Of course, we can't test every combination. So here's what Idecided to test:

A. Data on the #2 stopper establishes the base strength of the1/16" cable. B. Data on the #5 stopper establishes the basestrength of the 3/32" cable. C. Data on the #8 stopper establishesthe base strength of the 1/8" cable. D. Data on Camalot slingsestablishes 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, Rating1259 lbs, N = 220. 1/8" cable: Average 2970 lbs, Minimum 2607lbs, Rating 2248 lbs, N=190. Slings: Average 5781 lbs, Minimum5393 lbs, Rating 4946 lbs, N=236.

But, we're not going to be real sophisticated here, we'll just usethe average.

1/6" cable = 724 lbs. 3/32" cable = 1747 lbs. 1/8" cable = 2248lbs. 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 inthe field), not neatly dressed.

Average = 4363. Minimum = 4084.

Conclusion: girth hitching sling to sling loses 26% of the slingstrength. Given the high initial strength, the hitched system isstill 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 isstronger when girth hitched to sling than when run over the headof 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 ofstrength 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 ofstrength of 28%.

T6: 1/8" cable with sling doubled through it (rather than girthhitched).

Average = 3211. Minimum = 3054.

Conclusion: compare to 1/8" cable average of 2248 lbs. No lossof strength.

T7: 3/32" cable girth hitched with 3/32" cable (stopper to stopperextension).

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 actualstoppers are tested with the aluminum stopper at the top and a 10mmpin at the bottom. These commonly break at the top, where thecable folds tightly going into the stopper. Thus, in these tests,we can achieve "stronger than average results" because we arerunning 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 beginwith. Looks like the sling does not make it any worse, but thisis of little utility, since this is an aid piece anyway. Not strongenough 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 ofstrength, to down below the rating on the #5 Stopper. May be OKfor rappelling and low-impact falls, but not for general use.

1/8" cable (large stoppers)

These are usually considered truck. Tossing the sling throughresults 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 stiffunit, negating what is often the prime reason for extending thepiece in the first place.

Conclusive Overall Conclusions:

Girth Hitching a NYLON sling through reasonable size Stoppers isOK for low-strength operations, but should be treated with caution.Doubling the sling through, especially on the smaller sizes, isacceptable. Extending with cables suffers from some of the sameproblems, though to a lesser degree.

Spectra Slings - No comment, not tested.

And of course, everyone will draw the line differently. Protectinga 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. Forsetting a rappel? Acceptable I guess, in the larger sizes, butrepeated use might eventually cut the webbing.

Using smaller webbing than the BD 18mm nylon slings? Exercise morecaution.

That's my story, I'm a stickin' to it.

(signed) Tom Jones aka Jrat aka Ratagonius Utahness

[freeclimb9]

Rob,thanks for finding Jrat's test data. There has been testing done! I wish he could have checked out spectra also.

[ 03-26-2002: Message edited by: freeclimb9 ]