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Jim E

climber

away

Aug 18, 2010 - 01:34pm PT

yes.

http://www.dmmclimbing.com/news.asp?nid=293&ngroup=1
http://www.dmmclimbing.com/video.asp?id=5

edited to get the correct link

Studly

Trad climber

Aug 18, 2010 - 01:38pm PT

You're fine Coz. You would have to work pretty hard to figure out a scenario when you could shock load a dyneema sling out climbing enough to break it.

Jaybro

Social climber

Wolf City, Wyoming

Aug 18, 2010 - 02:38pm PT

Yeah, pretty unlikely that you'd break 'em. But why not just use real slings?

ontheedgeandscaredtodeath

Trad climber

San Francisco, Ca

Aug 18, 2010 - 02:56pm PT

Has anyone ever scooched above a rap anchor to deal with some clusterf#@$ or another? I reckon I have. If'n I slip while so doing, would I generate enough force to break these slings or cause my guts to shoot out my anus?

Seamstress

Trad climber

Yacolt, WA

Aug 18, 2010 - 03:10pm PT

Back injury/discomfort most likely. Breakage possible. Testing was persuasive to me.

Wade Icey

Trad climber

www.alohashirtrescue.com

Aug 18, 2010 - 03:32pm PT

guts shooting out of one's anus would be pretty persuasive..

Seamstress

Trad climber

Yacolt, WA

Aug 18, 2010 - 03:58pm PT

http://www.blackdiamondequipment.com/uploads/black-diamond/files/MM5824_C%20Runner-DBone%20WEB.pdf

Sewn slings do not stretch and will not
absorb energy during a fall or shock-load situation. Climbing
and mountaineering require the use of dynamic rope to absorb
energy during a fall.

I didn't find the "words" or test results that go along with the warnings, but the pictures clearly indicate that you should not tie into an anchor with it and girth hitching reduces strength to 35%. That is weaker than I remembered.

Ksolem

Trad climber

Monrovia, California

Aug 18, 2010 - 03:58pm PT

I think it would be hard to match the kind of shock load in the tests (a clean dead vertical drop) in a climbing situation. For example if you step up above a rap station to fiddle with something and fall, you will probably fall out from the rock some amount and swing back in as you load the sling on a curve.

That said, those tests and results are sobering.

"Guts out the anus..."

Classic!

charlie.elverson

Trad climber

St. Paul, MN

Aug 18, 2010 - 03:58pm PT

So why doesn't BD report the problem.

Some one should correct me if I'm wrong, but I was under the impression that although just as strong as a nylon runner, they're (almost) completely static. Where a nylon sling would stretch a (tiny) bit when loaded, a dyneema one won't. This means identical falls on a dyneema vs. nylon sling will generate greater forces because there is greater acceleration. Therefore, a dyneema sling is more easily broken in a fall straight onto it.

Seamstress

Trad climber

Yacolt, WA

Aug 18, 2010 - 04:16pm PT

Exactly. Thus the article a few years back in the climbing mags warning about clipping direct to anchors with the new fangled materials, and the continued reliance on nylon/perlon in the mountain rescue rigging practices.

I thought there was some good stuff on the Petzl or BD sites, but of course I can't find it when I want to.

aliebling

climber

San Francisco, CA

Aug 18, 2010 - 04:27pm PT

A newbie question:

If I'm using a taut dyneema sling (or the likes of a Metolius Personal Anchor System) as well as being tied in short to the anchor and am belaying from my harness when the leader takes a large fall, the force is going to be transferred to the anchor through the sling (since it is shorter than my rope tie in which has some slack in it).

Is this a problem? Will larger (potentially dangerous) forces be transferred to the anchor because of this? Do I need to ensure that my rope tie in (using a figure 8 on a bight) will be absorbing the fall and not a sling?

After reading:

http://wallrat.com/PDF_Files/forcesinleadfalls.pdf

I'm assuming that this case is not overly dangerous, as the force acting upon the belayer is generally pretty low...far less than that created by a factor 1 or 2 fall on to the sling itself. Again, my main concern is the danger of blowing the anchor due to forces being transmitted through the (comparatively static) sling and not the sling itself blowing (since I'm always tied in with the rope as well).

So, should I be making sure that while belaying any force transferred from belayer to anchor is through the rope tie in and not the sling or is this a non-factor?

Studly

Trad climber

Aug 18, 2010 - 04:37pm PT

I usually find it advisable when multipitch climbing, to tie off with the lead rope to the anchor with a clove hitch and equalize it to my daisy. That way you are dynamically roped in, equalized and backed up double.
If the leader were to take a fall with gear in, your weight acts as a counter weight and so the force is not so much taken by the anchors, but by you being pulled up in the air. If the leader were to fall directly on dyneema clipped off to the anchors, the stretch in the rope should not static load the dyneema or the anchors.
If you are worried about breaking dyneema slings, I suggest clipping off in your harness to a bouldering wall and trying to break the dyneema sling by climbing above it and jumping off, static loading the sling. It quickly becomes apparent that you do not normally put yourself in a situation belaying or climbing where you are going to be able to break the dyneema.

Brokedownclimber

Trad climber

Douglas, WY

Aug 18, 2010 - 04:39pm PT

I recently bought some Dyneema slings for tying off chickenheads, since they are narrower and would more easily conform to the rock without slipping off when using a chickenhead knot. This use would involve the dynamic stretch of the rope, but now I'm wondering if I wasted a lot of money?

aliebling

climber

San Francisco, CA

Aug 18, 2010 - 04:52pm PT

Studly, I quite like the idea of the clove hitch equalized to the daisy chain, thanks! Seems like the best of both worlds. My biggest issue with the figure eight on a bight was the difficulty in adjusting its length when needed.

BDC: I don't think dyneema slings are an issue when used attached to pro and taking falls, as the dynamic rope prevents their being shock loaded. For what it's worth, we use 8mm dyneema slings and have had no issue with leader falls.

Thorgon

Big Wall climber

Sedro Woolley, WA

Aug 18, 2010 - 04:53pm PT

BDC, in a dynamic Leader Fall scenario, the rope absorbs the impact force. That is what ropes are designed to do, hence "Dynamic Rope", the problem with Dyneema and Spectra is a fall scenario directly onto the sling! Some n00b (or anyone) girth-hitches a couple together at the belay and slips with slack in the system! Then, like the DMM video shows, the impact force can break the sling, due to Dyneema and Spectra's rigid properties! This can be avoided by simply keeping "slack" out of your anchor system... I have taken some big leader falls on BD Dyneema slings, with no problems and I weigh 220 lbs.!! The rope groans a little, but no problem with the slings!! Hahaha

Climb on,
Thor

Dyneema & Spectra are like using a swaged cable in their inherent properties!

Brokedownclimber

Trad climber

Douglas, WY

Aug 18, 2010 - 05:45pm PT

Thor-

That's what I surmised initially. I'm reserving them specifically for City of Rocks chickenheads, with my Edelweiss 10 mm rope.

Gary

climber

Desolation Basin, Calif.

Aug 18, 2010 - 05:48pm PT

An "authority figure" told me he'd use them for biner to biner only.

orsemaj

Gym climber

Aug 18, 2010 - 06:13pm PT

After watching all the guides in France climb with dynamic tethers, my wife and I started thinking about the idea.

Then on a burly decent in less than good weather, I jarred an old pin anchor pretty hard when a snowbridge collapsed on a couloir we were rapping. That really freaked me out. I only fell about one foot, but it really shocked the hell out of the system.

The next day we bought two DYNADOUBLECLIPs ( http://www.bealplanet.com/portail-2006/index.php?page=longes&lang=us);

I am very happy with the upgrade from all the other attachement systems I have used in the past.

bergbryce

Mountain climber

Oakland

Aug 18, 2010 - 06:28pm PT

Interesting video at DMM.

How do you store one of those Dynadoubleclips on your harness?

orsemaj

Gym climber

Aug 18, 2010 - 06:41pm PT

I primarily use the full length attachment and have it set up with a key lock locker. I pull it around my waist all the way to my haul loop or the third rear gear loop (crossing over the haul loop). I've also gone to the second gear loop but it hangs down a bit too much for me.

The only trick is getting all of ones gear or draws to lie on top of it. But this is pretty easy.

I've come to like this system quite a bit. WHen I was using daisies or the PAS, I would have to double up the sling on the biner and found that to be a hassel at times.

EdBannister

Mountain climber

Aug 18, 2010 - 06:41pm PT

Dyneema is manufactured by DSM in the Netherlands.
Spectra in manufactured by Monsanto in the US, but with more at least reputed irregularity than Dyneema, so if you are a discriminating manufacturer, you use Dyneema.

but, you can make a crude version at home.
Get the poly bag from the grocery run, or from some of the dry cleaners.
Pull on the sheet in one direction, as the stuff gets stretched, it gets stronger. The long poly molecules become increasingly paralell as they align in one direction, elasticity decreases and strength increases. As all fibers become paralell, there is no stretch, just loading, or failure.
hence:

Dyneema & Spectra are like using a swaged cable in their inherent properties!

not true, the braided steel stretches, dyneema or spectra, do not.

Please, forgive the tongue in cheek, i try not to joke about anything safety related, obviously it is correct to think that cable does not stretch, but an engineer would tell you that cable does stretch a bit, and that Dyneema does not.

In an application where stretch should be managed or minimized, dyneema is wonderful, i used it in a touniquet i designed a few years ago...
but my slings? the rope is dynamic, but i still use nylon slings.

edit, unlikely, but why not have the sling stretch rather than your spine compress... ?

Ain't no flatlander

climber

Aug 18, 2010 - 06:51pm PT

Or if you're BD, you call it your own special sauce named Dynex so nobody knows what they're buying.

Jaybro

Social climber

Wolf City, Wyoming

Aug 18, 2010 - 07:02pm PT

Do they still make Dyneema™? Why? Failed technology, move alone, there are better ways to save
weight.

cause my guts to shoot out my anus

absolutely classic!

EdBannister

Mountain climber

Aug 18, 2010 - 07:05pm PT

Now THAT is Funny!!! perfect call on BD.
Coonyard, as near as i can tell never designed anything, well,
since Tom Frost left,
but they sure have been good at copying and marketing.

Bill Forrest introduced pile to the climbing world because of it's functional perfect fit, his stuff pilled though and look like crap after a while, but it sure did work...

three years later Malden was weaving a softer, cushier version of "pile."
and whala "Synchilla" was born! amazing.

Allen A was selling the socks and ahem the underwear they private labeled for patagucci, at half the price... when i was at Liberty, i wanted to put the socks in the catalog as "Shoe-E-Nerd" socks but the owner just would not go for it.

and don't bring up camalots, they outsourced the design.

Moof

Big Wall climber

A cube at my soul sucking job in Oregon

Aug 18, 2010 - 07:13pm PT

While scary, it is an extreme test to drop 80 kg into a sling with zero give in the system. In the real world a climber who, for example, climbed up at a rap station to frig with something and slipped would be much squishier than the 80 kg weight. We have give in our harness, give in our spare tire waists, as well as our spine/legs/neck etc. I would really doubt the sling itself would break at forces below where it would snap your spine, rupture your aorta, etc.

So I would guess breaking a sling is unlikely using spectra/dyneema/nylon, but serious injury and possible intestinal inversion from a daisy/sling factor 2 fall is likely. Avoid it.

Yurr Gunna Dye!

Thorgon

Big Wall climber

Sedro Woolley, WA

Aug 18, 2010 - 07:19pm PT

Thanks, Ed.. O.K. Dyneema, doesn't have the same stretch that nylon does, that was the point I was trying to make!

I agree No Joking Matter, it's life and death.

Thor

sethsquatch76

Trad climber

Joshua tree ca

Aug 18, 2010 - 07:35pm PT

Coz,

DO NOT girth hitch with either specta or Dyneema runners!!!!!!!!!!!!!!! Dont have the numbers in front of me byt they are BAD!!!!!!!!!!!!! Stick to good old nylon!!!!!!!!!!!!!!!!

Your friend, who wants to see ya around for awhile Seth

mucci

Trad climber

The pitch of Bagalaar above you

Aug 19, 2010 - 12:26am PT

They are meant to be used AFTER your first piece off the belay.

Only "Biner to Biner" Not made for girthing chicken heads, threading etc.

Never in a belay!

I don't understand why you see people with triple lenght dyneema slings for thier anchoring rig?

I thought this was common knowledge? For YEARS!

The companies that produce these items made very clear the above dangers, and what threats they imposed on a system.

It's all about reading labels these days.

labrat

Trad climber

Nevada City, CA

Aug 19, 2010 - 12:43am PT

BD bashing again Coz? Why single out the company you worked for again and not the the others that produce this type of sling? I wonder if you knew the answer to your question before you posted it in the OP? Mammut, Petzl, Blue Water and Climb High all produce similar products. Any concerns about the Metolius PAS? The instructions for the PAS recommend girth hitching it to your harness.

Erik

Jaybro

Social climber

Wolf City, Wyoming

Aug 19, 2010 - 01:06am PT

The thing I don't like about dyneema/spectra, is that they wear out in no time, Weakrening appreciably by the minute. again,
why own it?

jfs

Trad climber

Upper Leftish

Aug 19, 2010 - 01:43am PT

Are you guys serious?

I'm being honest here...

Most everyone that posts here has been climbing for years. I know coz has at least. Was this a serious question? In all honesty it's way too troll-like.

Who in the hell actually thought that taking a factor 2 fall directly onto a Dyneema sling was OK??? Hell...who thought taking a FF2 direct fall onto a freakin' good ol' nylon sling was all peaches and roses?!?! Of COURSE the Dyneema will break...and of COURSE it will transmit MASSIVE amounts of force onto the climber. The force levels with nylon are huge too.

You mean to tell me all you dudes who've been climbing for DECADES........were unaware of the risk!?!?!

What the.........????? I'm shaking my head...

And to the folks freaking out and cutting up your slings...fine, whatever. Do what you gotta do to feel safe. But you are FLIPPING out over something that's been known and accepted and worked with for years. Yes there are risks...there are risks associated with every damn piece of gear we use as climbers......if we are idiots...

jeez... rc.noob around here.

And I'll second the weird coz and BD dynamic. Coz...if you got a bone to pick with BD...fine. But you're downright comical when you pull something like this. Like BD is the only dyneema sling maker out there... Please...

jfs

Trad climber

Upper Leftish

Aug 19, 2010 - 01:51am PT

Mike - from the DMM website...

It is also important to bear in mind that the characteristics of slings and quickdraws are also affected by the weave and blending of fibres, purposefully used to achieve particular handling qualities. Dyneema® slings are in fact usually a blend of nylon and Dyneema® fibres.

http://www.dmmclimbing.com/news.asp?nid=293&ngroup=1

labrat

Trad climber

Nevada City, CA

Aug 19, 2010 - 01:53am PT

jfs,
Check out prior posts by coz about BD harness loops. He has a bone to pick.
Erik

jfs

Trad climber

Upper Leftish

Aug 19, 2010 - 01:55am PT

That's kinda why I commented. I don't get it.

healyje

Trad climber

Portland, Oregon

Aug 19, 2010 - 01:57am PT

Just be aware that skinny [Mammut] 8mm dyneema slings have a finite lifespan nowhere near as long as nylon. Moderate trad use will drop the breaking strength of them from 22kn to 10-12kn at a rate of about 3-4kn per year. They were never designed to last essentially forever (like a nylon sling), but rather were specifically designed as a lightweight consumable item for those looking to go ultralite. These findings were a result of consecutive year testing over three years and I only used the slings about 2/3's of a year of climbing each year up here due to our rain.

Clint Cummins

Trad climber

SF Bay area, CA

Aug 19, 2010 - 02:57am PT

If you need a tether that can handle a short fall and not break itself or you:
Yates Adjustable Daisy with built-in Screamer:
http://www.yatesgear.com/climbing/etriers/index.htm

As for me, I don't use daisies or dental-floss width slings (but they are OK for leading if on my partner's rack; I just don't want to keep track of how old they are if they were mine).

Ain't no flatlander

climber

Aug 19, 2010 - 11:44am PT

So much nonsense in this thread. HMPE slings have been on the market for about 20 years.Can anyone point to a single failure in the real world? Verm's is the only one I recall hearing about and there were other factors involved. For that matter, the fears about using daisy chains to anchor are pretty absurd too (assuming you're smart enough not to cross-clip). A lot more serious stuff to worry about in climbing.

Largo

Sport climber

The Big Wide Open Face

Aug 19, 2010 - 12:38pm PT

Short course in UHMWPEs.

Dyneema and Spectra are different brand names for the same very strong fiber know in chemical argot as Ultra-High Molecular Weight Polyethylene - UHMWPE.

Both Dyneema and Spectra are gel spun through a spinneret to form oriented-strand synthetic fibers of UHMWPE. Gel spinning, also known as dry-wet spinning, is used to obtain high strength or other special properties in the fibers. The polymer (source material) is in a "gel" state, only partially liquid, which keeps the polymer chains somewhat bound together.

While the common usage of "polymer" suggests plastic, the term actually refers to a a variety of natural and synthetic materials.

In rock climbing, UHMWPE sling material is known as "tech-webbing."

The rule of thumb for "tech webbing" (Dyneema, Spectra, etc.) is to only use it as weight bearing, static links in the belay system. Any link in the belay system where one is moving around (such as with a daisy chain), use nylon, not tech webbing. The tech sling will likely not break in the event of a short fall directly onto the anchor, but as Rock and Ice testing showed some years ago, such shock loading can bust biners and rip anchors with frightening ease because these materials do not stretch much at all.

JL

dags

climber

Aug 19, 2010 - 12:47pm PT

Can someone explain why Dyneema isn't suitable for girthing chicken heads, threading, etc.?

If you're clipping in to Dyneema threads or hitched chicken heads and climbing on a dynamic rope, doesn't the rope provide the necessary dynamic "give" in the event of a fall? How is threading and hitching with Dyneema substantially different from clipping a piece of Dyneema to a cam or stopper?

I can understand if the threading or hitching causes the sling to run across a sharp edge, but that doesn't seem like a particularly safe thing to do with Nylon either...

HighTraverse

Trad climber

Bay Area

Aug 19, 2010 - 02:20pm PT

Mike.

I've heard many state Dyneema doesn't stretch. A shoulder-length Dyneema sling I have that took a fall is now about 1.5" longer than my others. Not propping or panning any particular gear, but clearly [a] Dyneema [sling] does stretch if you take a twenty+ footer on it.

This is a very interesting observation. The sling has taken a significant fall. However you say this sling is now 1.5" longer than the others. This leads to a few questions: Are all the others the same length? (I'll assume yes) Have they taken serious falls? (I'll assume no).
Then the fall sling has been stretched beyond its elastic limit. Retire it immediately, preferably cut into pieces.
Elastic limit is (simply) defined as the amount of force pulling on a material (a spring, a rubber band or your sling) that when the pulling force is released, the material returns to its original length.
Safe working stress for "classic" engineering materials is always much less than the elastic limit.

The energy used to stretch the sling or rope or carabiner is dissipated by the stretching and therefore isn't absorbed by the rest of the system. So in a fall, a stretching rope/sling/'biner reduces the mount of energy absorbed by the rest of the system (including your hopefully non-inverting guts).

By the way, it's not true that "Dyneema doesn't stretch". It certainly does, just a lot less than nylon for the same force IF IT'S THE SAME cross sectional area. Therefore Dyneema slings can be much thinner than nylon to hold the same load. If nylon or hardened steel are loaded below its elastic limit and then released it will also appear to not have stretched.

The entire system is complicated by the fact that nylon and Dyneema are vastly different materials and neither is a "classic" engineering material (like steel for instance).
So the only real data you can go on is dynamic test data.
Read the manufacturer's usage limitations and heed them. If any kind of load bearing material has permanently stretched get rid of it immediately.

I would not use Dyneema without being sure other parts of the system will be absorbing the fall energy.

dags
your reasoning is sound.

EdBannister

Mountain climber

Aug 19, 2010 - 02:38pm PT

would you put a biner on your rack that is not appropriate in some situations?

no.

so why would you put a sling on your rack that is not appropriate in some situations?

then any discussion about whether or not the stuff is as good or superior in some other application goes away.

when you are dehydrated, tired, maxed, and it's dark, and starting to rain, you don't need to be thinking about how to tie a knot, it should be so perfectly mastered that it is perfect every time, and by the same token, you don't want to have the need to discern between slings when setting up an anchor in the same conditions.

as for anytendancy to pick out a single purveyor of the stuff, that makes no sense. there are just two sources of the fiber, and four mills produce most of the web.

and, if you want a good scare??
put any web, nylon 1 inch, dyneema or whatever in between two trailer hitches and roll the cars or trucks apart a bit, then just touch a blade to it,
GONE!

where you can do so, tie in with your cord.

orsemaj

Gym climber

Aug 19, 2010 - 02:51pm PT

DYNADOUBLECLIPs http://www.bealplanet.com

This is the ticket. Or just make your own.

Hawkeye

climber

State of Mine

Aug 19, 2010 - 03:10pm PT

HT,

agree with all of your "engineering" speak on materials.

I would not use Dyneema without being sure other parts of the system will be absorbing the fall energy.

i would just point out that the word dyneema in this statement could be substituted with all other sling/attachement materials in use today....e.g. nylon, aluminim biner's etc....

i have first hand knowledge of falling a short distance onto a nylon runner, don't do it it hurts like hell. in other words, it won't absorb much.

like many of our tools, there are selective uses for dyneema where it's properties are desireable, (weight). i for one like to have some tied 9/16" as these are easier to deal with when having to leave bail slings. but if you are really worried you can go back to all 1" tubular nylon....

utahman912

Social climber

SLC, UT

Aug 19, 2010 - 03:48pm PT

DYNACLIPs? still NA in USA?

handsome B

Gym climber

SL,UT

Aug 19, 2010 - 06:03pm PT

The BD belay loops are sewn the way I said. Why if I have a concern with a product I'm bashing?

Because your "concerns" are simply fear mongering based on unscientific observations. You were proven wrong before so your credibility in this situation has been lowered

I will not be using a sling that can break, sorry that's my deal, regular slings are bomber. I saw no label or warnings before I used them, been out of the loop. We use tons of tech cord in rigging, just not for climbing.

No. All climbing equipment will break if used improperly. Ropes will cut when loaded over an edge. Carabiners will break when the gate is open. Belay loops will fail when heavily worn.
Taking a factor 2 fall onto a static piece of climbing gear will break either you or it.

I really fear for your clients if you are this uninformed.

cintune

climber

the Moon and Antarctica

Aug 19, 2010 - 07:05pm PT

Then too, they're not 100% dyneema, just the white strands.

Oxymoron

Big Wall climber

total Disarray

Aug 19, 2010 - 07:26pm PT

Agree with Mike. Not very durable.

the kid

Trad climber

fayetteville, wv

Aug 19, 2010 - 07:59pm PT

Nylon Bro..

handsome B

Gym climber

SL,UT

Aug 19, 2010 - 09:17pm PT

Coz Wrote

Handsome b, BD troll ru????

No, I don't work for Black Diamond. I climb on some of their gear because it is good, but some of it sucks.

Fear mongering, ask Tom Jones about the belay loop, he design it for BD. It is weaker fact dude, he thinks it protects the stiching.

It sounds like he knows what he is talking about, I am sure he has an engineering degree and the resources to test his handiwork. I am sure a team of other engineers tests his work as well as the commissions that certify climbing gear both in the US and Europe

I like the tac going through all way through. It's stronger anyone knows this it's common knowledge.

Sounds right to me. I climb on aluminum carabiners. Do you climb on steel carabiners because they are stronger?

I was handed a bunch of sling and saw no warning or had any idea they where dyneema
I think for myself I think it's dangerous to have tec slings! Period

My clinets do not use them, I keep it simple.

This is what freaks me out. If you can't tell the difference between nylon and dyneema (BD uses Dynex) then how can you tell the difference between a static and dynamic rope?
If you were given a rope without markings could you safely use it?

You seem dangerously misinformed about the basic properties of climbing gear.

labrat

Trad climber

Nevada City, CA

Aug 20, 2010 - 11:53am PT

coz,
Do I work for BD? No.

Do you make up ways of bashing them and calling them out because you have past experience that colors your judgement. Yes. I see the anger every time you write about BD. Does your agenda leak through your poor arguments and statements? Yes
Erik

EdBannister

Mountain climber

Aug 20, 2010 - 03:03pm PT

Locker has it right, again.

ontheedgeandscaredtodeath

Trad climber

San Francisco, Ca

Aug 20, 2010 - 03:23pm PT

My brain says nylon, but my legs and arms say lightweight!

utahman912

Social climber

SLC, UT

Aug 20, 2010 - 05:38pm PT

The truly amazing thing is that DMM would do the test, produce and publish the results, and continue to manufacture slings using dyneema.

Could it be they assume climbers are being smart enough to read instructions and use products as intended? Problem is we aren't always that smart and the instruction sheets are in so many languages that it is near to impossible to find the part written in English. Often climbers get hand-me-downs from a mentor without the instructions and the mentor didn't read them or use the product as intended anyways.

If you see someone doing something like climbing above an anchor on dyneema or using it in some other dangerous fashion, why not teach them about the principles behind the thing on the spot in person?

Most of the climbers I see out and about: learned how to do something once from someone and have never given what they were taught a second thought, don't peruse the internet looking for tips and tricks, have never read a climbing how-to book, and are just plain uninformed... so help them out with some info where they can get it... at your local crag.

I have received great counsel this way... also some not-so-great

:-)

jb

jfs

Trad climber

Upper Leftish

Aug 20, 2010 - 05:53pm PT

So apparently it is now ok to climb above your nylon sling anchor and lob off anytime you want. I mean...it's only 12-15kn hitting you. No big deal.

What the...?!

Just don't do it with Dyneema...because it might break...right after you crap out your lower intestine.

Jeez. Same principles apply on any kind of static material. You are screwed either way. The idea that a dyneema anchor is les safe is based on ignorance and/or a poor understanding of basic safe rockcraft.

Period.

utahman912

Social climber

SLC, UT

Aug 20, 2010 - 06:13pm PT

So apparently it is now ok to climb above your nylon sling anchor and lob off anytime you want. I mean...it's only 12-15kn hitting you. No big deal.

Good point... shoulda said anything static :-)

Maybe even don't climb above the anchor until you are starting the next pitch and belayed on the climbing rope...

froodish

Social climber

Portland, Oregon

Aug 20, 2010 - 06:21pm PT

Maybe Russ will make up some swedged cable PASes. That way you'd be sure to kill yourself in a fall before they broke.

August West

Trad climber

Where the wind blows strange

Aug 20, 2010 - 06:33pm PT

Ok, serious question (not trolling). Are there any reports of someone clipped into an anchor with standard length slings and managing to break them in a static fall back onto the anchor?

An attached weight (like the lab test) is not going to behave like a human body in a harness. I rather suspect many more lives good be saved if climbers only clipped into anchors using dyneema slings, but always wore helmets when climbing...

Seamstress

Trad climber

Yacolt, WA

Aug 20, 2010 - 07:06pm PT

The human pelvis generally can withstand up to 12 KN of force. For MRA testing purposes, a force of 15 KN force on an anchor exceeds safety parameters, and implies a force of 7 - 12 KN on the human component if the load is directed through a pulley/biner.

I am not signing up for a factor 2 fall on anything "static" unless I am totalled screwed/out of gear.

jfs

Trad climber

Upper Leftish

Aug 20, 2010 - 08:18pm PT

Isn't understanding the limitations of various pieces of equipment an important part of basic safe rockcraft?

Yes.

As is being able to rationally assess and work within those limitations... which is where some people seem to be falling short. That's my point.

For the record...I have no connection to BD. None.

There is no reason to stop using Dyneema materials based on the tests provided by DMM. If you put yourself in a situation where you are taking factor 1 or 2 falls directly onto your anchor...you screwed up...and life will suck BADLY no matter what material your anchor is built out of. The idea that nylon "doesn't break" is silly. The idea that it's not OK to fall onto a dyneema sling and yet STILL ok or somehow appreciably safer to fall on a nylon sling is...well...also silly. Both are failures of technique and systems before you ever get to the point of actual material failure. To freak out and cut up your dyneema slings after seeing these tests is a failure to understand, rationally assess, and apply basic knowledge.

However...to do so simply because it makes you feel safer...go right ahead...do what you gotta do. Just no need to run through the streets screaming like a loon.

Peace.

utahman912

Social climber

SLC, UT

Aug 20, 2010 - 10:57pm PT

Those of you who use a Purcell, do you use it exclusively? Hanging belay included?

rgold

Trad climber

Poughkeepsie, NY

Aug 21, 2010 - 12:29am PT

It is certainly old news that falls onto static materials can produce catastrophically high forces. The UIAA journal had an account a number of years ago of a factor-two fall on a quickdraw causing one of its carabiners to break; the climber decked. At that time, Petzl subjected some of its standard nylon runners to factor-2 falls and got maximum impact loads of 18 kN, well above the 12 kN so-called maximum acceptable load for humans (in a parachute harness, I think).

Of course, we tend to ignore the extensive European knowledge base, so the subject had to be revived by Mike Gibbs, at first in 2002---see

http://www.marski.org/index2.php?option=com_docman&task=doc_view&gid=74&Itemid=26

http://www.caves.org/section/vertical/nh/53/RiggingForRescue-DaisyChains-2005.pdf

These tests, in which the Metolius PAS broke in factor-1.25 falls, may have been discounted by even the climbers who knew of them because of the 100 kg rescue-appropriate weights used. (It may be of interest to note that OSHA regulations for "positioning device systems" for a single individual require them to withstand a factor-2 fall with a 250 lb (113 kg) weight.)

The Gibbs tests also indicated that a Purcell prussik tied in 6 mm or 7mm cord was a far better option. Given the moderate adjustability of the Purcell prussik tether, it remains a better solution than the single-length Beal tethers. With regard to the sewn fixed-length tethers mentioned by orsemaj, it is worth reading the French study

http://www.caves.org/section/vertical/nh/53/lanyard_tests_v6.pdf.

Their conclusion is that a tether made of the same rope material but knotted at both ends is a significantly better load limiter---the tightening of the knots has a significant energy-absorbing effect. In other words, the homemade version is more effective than the commercial version.

Getting back to HMPE tethers, a few years after the Gibbs reports, Sterling ropes replicated the breaking of the PAS, but this time with 80 kg weights and a factor-2 fall. In response, they brought out a nylon PAS clone, the Chain Reactor, which will hold several factor-2 falls without breaking (which does not mean, as in the quickdraw accident, that something else will not break).

Nobody on or off-line made a fuss about Metolius continuing, as they do to this day, marketing the PAs---and it is a dedicated tether, not a sling whose primary purpose is to extend protection. The SuperTopo site recommends the PAS without acknowledging any of the breakage results and does not even mention the Chain Reactor. The comments I posted to that review were, last time I looked, totally ignored by other posters. So I think it is fair to say that there is little to no sense of urgency in the climbing community about whether or not HMPE materials are suitable for tethers.

DMM was several years late to this particular game, and their results were already known. As a result, suddenly singling out BD makes little sense; there are many purveyors of dyneema slings and, in any case, tethering is hardly the primary function for climbing runners, which work just fine used as runners.

As to the question of whether dyneema slings or the PAS will really break with a human rather than 80kg of steel on the other end, I think the honest current answer is that we don't know. Various tests have shown that human weights do not produce as high a maximum impact load in fall situations, so the braking of dyneema slings with an 80 kg steel weight does not necessarily mean that the sling will break with an 80 kg human. Some people are already certain HMPE slings won't break with human weights, but I for one don't know what data their certitude is based on.

The explanation that humans are squishy and harnesses "give" don't come close to explaining the claimed discrepancies in impact loads. My guess is that humans are a collection of jointed weights which are not stopped at the same instant and are not all moving downwards at the moment of impact. More and more realistic test dummies are being produced, and are beginning to find their way into the testing of climbing materials, so we should expect some revised test results realtively soon.

so what to do in the meantime? I think that focusing on the hypothetical breaking of HMPE materials under human factor-2 falls is the wrong emphasis. The real point is that using either HMPE or nylon tethers in situations where they might be called on to absorb fall energy will produce dangerously high loads to the system and the body---something is likely to break, even if it isn't the tether itself. HMPE is worse, but nylon runners are still plenty bad enough. And this if for factor-1 falls, which are a potential common result of a tethered fall.

So, slngs or tethers or daisy's are a truly inferior approach if a climbing rope is available for anchoring.

If a climbing rope is not available, as in rappelling situations, then it is really important for the climber to remain below the anchor with as little slack as possible in the tether. Moving above the anchor, which of course sometimes has to be done, should be treated with the same caution and attention as if one was free-soloing, because breakage or not, you are in a serious danger zone.

jfs

Trad climber

Upper Leftish

Aug 21, 2010 - 12:43am PT

^^^ rational. Thanks.

jfs

Trad climber

Upper Leftish

Aug 21, 2010 - 01:00am PT

^^^ rational. :-)

Moof

Big Wall climber

A cube at my soul sucking job in Oregon

Aug 21, 2010 - 01:14am PT

Yurr Gunna Dye!!!

sethsquatch76

Trad climber

Joshua tree ca

Aug 21, 2010 - 06:36am PT

Excellent post Rgold!!!!!!!!!!!!!!

Tomcat

Trad climber

Chatham N.H.

Aug 21, 2010 - 08:39am PT

I jumped on the wagon when the skinny slings came out too.I still carry four as so-called "alpine draws",or more correctly"trad draws" and like them as they seem to transfer the least amount of uplift to a stopper placement,or cam that may walk.Since the Goran Kropp incident I am more circumspect about using sport draws on cams.

It's important to consider what Senor Healy has contributed,as well as rgold's always excellent input.These slings diminish in strength at a considerable pace,which for some of us conflicts with the cost.The loss of strength,coupled with the other aspects,is potentially a serious combination.

Meanwhile the quality and ruggedness of the oft used 11/16 nylon products has improved,particularly a Mammut product I love.I now carry a mix of these sewn and knotted.

After bailing from a ways up on Cannon one day,where rap anchors are seldom bolted,if they exist at all,and having to link three or four skinny slings together,since any knot is verbotten,to sling a big block,I got over these real fast.

They have a place,and a use,but it's not universal.I'm always amused how may people say they carry them to save weight,then launch up two pitch routes with six lockers, a mini traction,two rappel/belay devices and two cordelettes.

healyje

Trad climber

Portland, Oregon

Aug 21, 2010 - 09:46am PT

jfs: The idea that it's not OK to fall onto a dyneema sling and yet STILL ok or somehow appreciably safer to fall on a nylon sling is...well...also silly. Both are failures of technique and systems before you ever get to the point of actual material failure.

klk

Trad climber

cali

Aug 21, 2010 - 11:13am PT

The comments I posted to that review were, last time I looked, totally ignored by other posters. So I think it is fair to say that there is little to no sense of urgency in the climbing community about whether or not HMPE materials are suitable for tethers.

Yeah, no kidding.

Climber equipment preferences and practices have little to do with rationality.

Mighty Hiker

climber

Vancouver, B.C.

Aug 21, 2010 - 04:30pm PT

Thanks, Rich - as always, an informative and useful post. As with so much new climbing equipment and technique, a closer examination often shows that what is promoted as the latest and greatest, isn't necessarily.

In many situations, I'll just continue to use regular nylon products, tie in with the rope, and belay off my harness. It seems to be not only more versatile, but safer.

Hawkeye

climber

State of Mine

Aug 21, 2010 - 10:32pm PT

this is obviously an rc.noob thread....

rgold

Trad climber

Poughkeepsie, NY

Aug 22, 2010 - 12:04am PT

That's me all right---just subtract the 52 years I've been climbing, add some dorky glasses, and voila!

utahman912

Social climber

SLC, UT

Aug 22, 2010 - 12:41am PT

this is obviously an rc.noob thread....

I admire you for being able to endure 5 pages of it :-)

labrat

Trad climber

Nevada City, CA

Aug 23, 2010 - 09:45pm PT

Bump for how much I learned from reading this thread!
Erik

utahman912

Social climber

SLC, UT

Aug 23, 2010 - 10:04pm PT

Here, here. I'll be hanging on a purcell prusik 21 hours from now :-)

jb

roy

Social climber

New Zealand -> Santa Barbara

Aug 24, 2010 - 02:12am PT

Hi,

Most of the time I'm building an anchor from the rope (double ropes) and using a sling for a backup piece if necessary. But if it's a two bolt anchor and/or we're not swinging leads I've been using a cordalette tied from dynamic prusik cord (8 mm from Yates).

I like the idea of the dynamic connection but there's an untested aspect to this. These cords have a lower breaking strength than most sling material (9.7 kN for the 6.5mm to about 12 kN for the 8mm). And if the cordalette is knotted with a figure 8 that's probably going to both increase the dynamic aspect and further reduce the strength.

So what I would really like is for someone with a DMM like test rig to drop 80 kg onto this arrangement. Any takers? Let me know what happens.

Thanks, Roy

apogee

climber

Aug 24, 2010 - 02:14am PT

Weld_It hooked me up on this shite...

It's bomber!!!

Hawkeye

climber

State of Mine

Aug 24, 2010 - 10:30am PT

yeah, i will buy that stuff from weld-it.

the rcnoob comment was that this stuff all SHOULD have been known by ANY CLIMBER who uses the skinny. it is downright shocking to think that many had no clue....

Jim E

climber

away

Aug 24, 2010 - 10:37am PT

Roy,
Send me a six pack of Kiwi Lager and I'll do the drops for you.

Morgan

Trad climber

East Coast

Aug 24, 2010 - 10:58am PT

What about slings on cams? It seems like DMM, HB, Metolius, CCH, Trango use some type of Dyneema or Spectra slings. Interestingly, it looks like Black Diamond has decided to stick with nylon on the Camalot C4s and maybe the C3s, too. And they usually do things for a reason.

slobmonster

Trad climber

OAK (nee NH)

Aug 24, 2010 - 11:56am PT

What about slings on cams?

It all depends on what the manufacturer uses to cover the bare cable.

(TTBOMK) BD uses Nylon slings on its cams because it uses an Acrylic tubing, through which a Dyneema sling would quickly and easily cut.

(IIRC most other cam manufacturers use a Urethane tubing.)

Matt M

Trad climber

Alamo City

Aug 24, 2010 - 12:20pm PT

Not true. BD Used nylon in the previous version of Camalots as well (no thumb loop). My guess is BD uses nylon because it's more durable over the long rung than dyneema (see above re: faster loss of strength in skinny dyneema)

The tubing material used makes no difference. In testing the C4s, the thumb loop would collapse and CUT the sling BOTH Dyneema and Nylon. BD uses a double layer of sling to prevent loops deformation. (Metolius does this as well on the TCUs I think)

See Here for the full explanation: http://www.blackdiamondequipment.com/en-us/journal/climb/all/qc-labreslinging-camalots-and-c3s

slobmonster

Trad climber

OAK (nee NH)

Aug 24, 2010 - 02:40pm PT

Yeah I'm with you; the double-layered webbing is quite significant.

I might have been regurgitating an explanation given to me by another cam manufacturer, but I do recall something about the tubing used to cover the cable. Sorry to obfuscate this ridiculous discussion further.