Two Opposite and Opposed Carabiners: Possibly Weaker Than a Single Carabiner

By all means test it

But just because one finds something doesnt take 20 kn doesnt mean we should stop climbing on it .... Especially if there is no real world accident in decades of climbing

I mean i assume everyone here uses gridlock biners because we all knot a belay biner "can" break at 7 KN ... Despite no known reals world accidents we know of that happening

I predict no matter what that well have hordes of newbies running around saying 2 opposed biners is no longer safe for TR ...

;)

These threads don't teach us anything about rock climbing. What they teach us about other climbers is a wonderful thing.

nicelegs wrote:These threads don't teach us anything about rock climbing. What they teach us about other climbers is a wonderful thing.

+1

ChefMattThaner wrote: +1 Looks like the beginning of another "it will never kill you but let's argue it any way" thread. 26kn on top rope is damn near impossible.

I don't think the point is this configuration will kill you as your body would break in half well below 26kn. To me its more of, hmm never though of that, I wonder what this other situation would do... There are so many variables in climbing and rescue so each time we are exposed to something like this it makes us think which can't be all bad.

I am honestly surprised, although I probably shouldn't be, by the outright dismissal of the value of these tests. Doak brings up some good points about scenarios where the loads really could be significantly high. And, although I'll take it as granted that there are no reported top rope carabiner failure accidents, there are plenty of examples of equipment failure, often due to failure to understand the limitations of the same.

I can think of 2 deaths/injuries off the top of my head relating to carabiner failure that surprised me, just in the last few years, albeit other might have understood these risks beforehand. I believe both were in the Red River Gorge: a rope getting cut by a worn, sharpened aluminum carabiner, and a carabiner breaking when somebody fell while clipped directly to a bolt with a quickdraw.

If new research leads to new understanding of the equipment we entrust with our lives, and prevents an accident someday, I fully support it. Hell, I support it just because it's interesting. Thanks, 20kN, for always posting these and your own results.

From that video:
1. you cannot tell what biners are used.
2. you cannot tell how they are configured.
3. you cannot see the set up of the sling; it appears to be girth hitched on itself
4. you cannot see if the sling is tubular or what material it is made of
5. there are no numbers for failure rate of the biners or the sling.

Overall, no information to even discuss this, unless there is somewhere that the OP is getting these numbers from and pictures for configuration and materials used. WTB link please.

Don Ferris wrote:He's not saying a TR fall will generate these kinds of loads (26kn). He is pointing out that with two steal lockers rated at 50 kn a piece, because of the opposite and opposed setup, failed at around half of what they were rated. So, if all things remained the same except with aluminum lockers rated at 24kn a piece, it is feasible that they might fail at 12-13 kn which in some rare scenarios is possible to generate in a climbing fall.

am i the only person that found it ironic that don ferrous mis-spelled steel?

The cutting of ropes over sharp edges and biners have been known for many years ... Ill post up the DAV articles when im back on a real computer

As has poor loading of single carabiners ... The petzl documentation warms explicitely about it i believe as has the BD qc lab

blackdiamondequipment.com/e…

This is common sense .... Odd carabiner loading and sharp edged are dangerous

This is taught to new climbers in courses (or damn well should be if youre a credible "teacher") all the time

As others have expressed the danger is NOT both biners breaking in a TR/lowering situation ... It is in the gate coming open and the rope coming out ... This is what opposed biners prevent

Again if you can show an accident where 2 opposed biners both failed in a climbing situation there a reward ... I believe it even extends to "realistic" tests

rockclimbing.com/cgi-bin/fo…

By all means test it ...

But we are not pull test machines, and realistically if you are worried about the strength of 2 opposed biners, ive got a whole list of things you should stop using

Ive said it before ... People will argue about this and every other minor "safety" issue on the intrawebs ... And ive seen newbies at the crags shouting it out loud ...

Its not whats going to kill you

I find it amazing how so many can argue about deadly opposed biners, gridlocks, deadly dyneema, etc ... And how they want to be "safer"

Yet not take the most basic precaution against a known killer ... A helmet

;)

Are there any documented instances of real world situations where toprope carabiners fail when set up correctly?

I've attached a photo of the worst top rope setup I've ever seen. The climbers were dogging all over this and I obviously don't recommend it but was impressed that the carabiner that was actually taking the load didn't snap.

Once notified of my concerns about their setup they let me fix it right away.

As an additional note: I think this kind of thing happens when people don't learn anchor building, but simply think they can quick two quickdraws to bolts and call it done no matter what. This setup happened in the lower gorge of smith rock in an area where the bolts are on top of the cliff band instead of on the face.

When I use 2 biners for my masterpoint, I use one locker and one non locking. They must be of nearly or identical design and shape, and I do not reverse the gates since one locking carabiner is sufficient for any 'accidental' unclip. Mixed gate and shapes or sides up or down can add twist or stress to the rope running through the carabiners, thus I do not switch them around. Works fine, accident free top rope anchoring system for me the last 35 plus years.

Bryan Hall wrote:Are there any documented instances of real world situations where toprope carabiners fail when set up correctly? I've attached a photo of the worst top rope setup I've ever seen. The climbers were dogging all over this and I obviously don't recommend it but was impressed that the carabiner that was actually taking the load didn't snap. Once notified of my concerns about their setup they let me fix it right away. As an additional note: I think this kind of thing happens when people don't learn anchor building, but simply think they can quick two quickdraws to bolts and call it done no matter what. This setup happened in the lower gorge of smith rock in an area where the bolts are on top of the cliff band instead of on the face.

That TR anchor is setup incorrectly. The issue is not two opposite and opposing carabiners, but way that the anchor is constructed.

NC Rock Climber wrote: That TR anchor is setup incorrectly. The issue is not two opposite and opposing carabiners, but way that the anchor is constructed.

Yep, I know that and stated it when I posted it. I used it as an example to show that even in what I would consider a worst case scenario the carabiners still didn't break. This setup seems far worst than this theoretical opposite and opposed problem since this is a single carabiner folded over the edge of the cliff.

My question was is there any instances of top rope carabiners failing when they are set up correctly?

Bryan Hall wrote: Yep, I know that and stated it when I posted it. I used it as an example to show that even in what I would consider a worst case scenario the carabiners still didn't break. This setup seems far worst than this theoretical opposite and opposed problem since this is a single carabiner folded over the edge of the cliff. My question was is there any instances of top rope carabiners failing when they are set up correctly?

You did state that. I should have done more than just skim your post.

I don't think that there is an instance of biners failing when set up correctly. Others might have proof otherwise.

I think that your point regarding them not failing just shows how hard it is to break this stuff in a TR situation. I am not saying that biners don't break or that proper alignment is not important. I am saying that there are a lot of bad / marginal anchors out there and that we seldom (ever?) hear about carabiners breaking in tr anchors.

NC Rock Climber wrote: You did state that. I should have done more than just skim your post. I don't think that there is an instance of biners failing when set up correctly. Others might have proof otherwise. I think that your point regarding them not failing just shows how hard it is to break this stuff in a TR situation. I am not saying that biners don't break or that proper alignment is not important. I am saying that there are a lot of bad / marginal anchors out there and that we seldom (ever?) hear about carabiners breaking in tr anchors.

Agreed.

Bryan Hall wrote:Are there any documented instances of real world situations where toprope carabiners fail when set up correctly? I've attached a photo of the worst top rope setup I've ever seen. The climbers were dogging all over this and I obviously don't recommend it but was impressed that the carabiner that was actually taking the load didn't snap. Once notified of my concerns about their setup they let me fix it right away. As an additional note: I think this kind of thing happens when people don't learn anchor building, but simply think they can quick two quickdraws to bolts and call it done no matter what. This setup happened in the lower gorge of smith rock in an area where the bolts are on top of the cliff band instead of on the face.

From the picture you posted above, the QD's may have been and most likely were properly installed. The topropers were probably flailing about and spinning around the rope. This caused the anchor to twist around.

This is why I only top rope with 7 HMS biners.

that pic of the fuhklempt tr anchor looks to show rappel wear on the one quickdraw biner...
makes the anchor situation none too surprising.

rocknice2 wrote: From the picture you posted above, the QD's may have been and most likely were properly installed. The topropers were probably flailing about and spinning around the rope. This caused the anchor to twist around.

I seriously doubt that. I have never in 8 years of climbing and guiding seen climbers flail on a top rope in such a way that the quickdraws move upwards, twist over each other and then settle onto an edge. Everything I know about physics, climbing, rope and anchor systems defies the possibility that the top rope caused a correctly set up anchor to do that.

20 kN wrote: I might try to pull test some AL non-lockers O&O to see if I can replicate the results of his testing. If two locking steel carabiners are failing at loads that low, I am curious what would happen with the ever-common double non-locking aluminum biner O&O configuration.

As someone who has had a powerpoint screwgate snap on him, often uses back-to-back snap gates rather lockers, uses two lockers to attach his silent partner and who sometimes leads using a pair of lockers rather than by tying into the rope, I would be very, very, interested in any results you come up with! Thanks.

So many people here have missed the point....