clipping quickdraws together via caribiners

Can someone tell me... I got in a discussion with a coworker about the safety of clipping quickdraws together. I've always been taught that you should clip 2 quickdraws together by clipping the draw to the dog-bone part of the other draw, not just from the caribiner of one draw to the caribiner of the other draw. I've heard that it is actually really unsafe to clip draws together, caribiner to caribiner. Does anyone out there know exactly why this is unsafe, if it really is?

Here's my totally unscientific opinion. I've had to extend and clipped metal biner in a quickdraw into a metal biner on a sling and held body weight with it. The pull force of the biner is the same whether it's a dogbone pulling it, or another biner.
That being said, i wouldnt want to put a fall force on a biner x biner system, because to me it seems like the metal could create a burr or something that would be detrimental to rope.

Mary Harlan wrote:Can someone tell me... I got in a discussion with a coworker about the safety of clipping quickdraws together. I've always been taught that you should clip 2 quickdraws together by clipping the draw to the dog-bone part of the other draw, not just from the caribiner of one draw to the caribiner of the other draw. I've heard that it is actually really unsafe to clip draws together, caribiner to caribiner. Does anyone out there know exactly why this is unsafe, if it really is?

The only reason it is more risky is that biners have a higher chance of unclipping each other. Just play around with it and the spines or gates can very easily open up the other gate. I wouldn't chain them biner to biner for any sort of extended draw while climbing, but I regularly do this when cleaning a route because I don't carry any specialized gear for taking myself off belay, and just use a combination of the draws and slings I may be carrying.

Do this at home. Clip two non-locking biners together, and then twist them, they can unclip from each other.

Last time this was brought up someone posted a half dozen pictures of pros on upper-end 5.14 routes using metal on metal extended drawS.
If it's good enough for Sharma...
It's also uber common in aid climbing.

Boissal wrote:Last time this was brought up someone posted a half dozen pictures of pros on upper-end 5.14 routes using metal on metal extended drawS. If it's good enough for Sharma... It's also uber common in aid climbing.

Just because someone sends 5.14 doesn't mean they don't employ unsafe practices. How many "pros" in the 80's were rocking american death triangle anchors? Plenty.

Generally speaking, there's no single "right" way to do things, but there are plenty of wrong ways. It would behoove every climber to learn what they are and avoid them.

I just did some quick home testing, and I found it easier to unclip a draw from a bolt hanger by flicking it than to get a draw to let go from another draw. Either way, it took some aggressive action.

Try it at home with your equipment and decide for yourself.

Edit: I actually found it easier to unclip with just one biner between the dogbones. Clipping the rope with this configuration is easier, however.

A guy took it upon himself to extend my two quickdraw anchor at Red Rocks Open Space some years ago. He did this by clipping two more quickdraws into the gates of mine. When I climbed up to the anchor, one of the sets of quickdraws had come unclipped and I was only on the second set. So there is one anecdotal incident for you.

On the other hand, in some aiding situations it's fine. But this is mainly because constant weight is on the carabiners.

Well, I have done a ton of aid climbing, using biner on biner, and theoretically, you aren't taking a shock loaded fall in that scenario.

What I thought was that if I used the language in posing my question, "...metal on metal", someone might say, "Well, a bolt is metal," so I didn't pose the question that way. I also thought that a bolt has dynamics built into the system, because, after all, the actual bolt is generally an expansion bolt that is designed to hold shock loaded weight, by actually camming when you first set the bolt in the rock. These bolts are meant to have dynamic force placed on them.

When you clip 2 caribiners together, it's like clipping 2 static forces together, right? Are the way caribiners engineered designed to have dynamic forces put on them when clipped together?

As far as pro climbers go... I climb with a handful of them and have some sponsorships myself; pro climbers are like everyone else: some are super safe (I'd say all of them I've climbed with), and some aren't, and we should all choose our partners wisely.

I feel like I need a scientific explanation to this, regarding the materials used that allow a metal object, like a caribiner, to have a particular amount of dynamic forces placed on it, and how it behaves when 2 are enchained and dynamic forces (like a lead fall) are placed on them.

It's not about materials. Metal on metal won't cause any real damage. It's more about how there is a chance of them unclipping. Really, biner on biner isn't horrible, biner on biner on biner is when things get bad. Either way, it's often clusterfucked and fidgety so I rarely do it. If somehow you are left with no other option, it'll work.

Mary Harlan wrote: I feel like I need a scientific explanation to this, regarding the materials used that allow a metal object, like a caribiner, to have a particular amount of dynamic forces placed on it, and how it behaves when 2 are enchained and dynamic forces (like a lead fall) are placed on them.

The ability of metal connections to resist dynamic forces is not the issue. There is nothing intrinsically the matter with "metal on metal." Several folks have explained the problem, which is not at all hypothetical: the carabiners can twist at impact in such a way that they unclip. I know of several incidents over the years in which this really has happened, and of course the experience gained from those accidents is the source of the admonition not to clip draws together.

The original incident that brought the issue to the forefront was in the 1950's. Mark Powell, who was at the time one of the leading Yosemite climbers, shattered his ankle in a fall in which a chain of either two or three carabiners unclipped. The use of several carabiners sounds bizarre nowadays, but in the 50's it was not at all uncommon---before Mark's accident---to clip the rope to a piton with two or three carabiners in order to cut down on rope drag.

Having the biners twist and unclip is a low-probability event, so people can get away with it for years. But it is not so unlikely as not to have happened, with bad consequences, a number of times since Mark's accident.

as several others have said, the reason that it isn't optimal to go biner on biner is that if movement causes them to twist, they are more likely to unclip. this can also happen with a single biner clipped into a bolt (and it has happened), where movement has opened the gate and unclipped it, or jammed the biner into the hanger such that it will be crossloaded. with 2 biners there are 2 gates that have an opportunity to be opened.

shock loading doesn't really have anything to do with it, or how bolts work. bolts aren't necessarily designed for dynamic loading. For the temperatures, load rates, applied stress being considerably less than the yield stress, etc, etc, the materials that bolts and biners are made from can, for all practical purposes, be considered to not really have rate determined stresses. in plain english - the bolts and biners really don't give a shit how quickly you load them.

Mary Harlan wrote:Well, I have done a ton of aid climbing, using biner on biner, and theoretically, you aren't taking a shock loaded fall in that scenario.

i think most people don't really understand what terms like 'static', 'dynamic', 'shock loaded', etc mean. for example, you probably think that you aren't producing a dynamic load on your piece while you are aiding, and you would be incorrect. walking up the ladder, no matter how carefully you do it, will produce fluctuations in load on the top piece. the only way the top piece would be 'statically' loaded would be if there was no movement of the item causing the load.

on a similar note, you often here people say that you can't put a shock load on a dyneema sling because it is a static sling. again, this isn't really the case, a dyneema sling doesn't have a stiffness of infinity.

Yer Gunna Die!

Where are people learning to climb these days? This is first day stuff.

If you don't know the answer to this question stop climbing immediately! Hire a guide or read a book before risking your life. DUH!

Your Gonna Die!

This thread is seriously painful to read. I'm gonna have to quit this forum for a while.

It's not an issue of metal on metal, we do that every time we clip a bolt, or a nut for that matter. It's an issue of biner to biner, they can easily unclip themselves during the motion of a fall. Basically every time you go biner to biner you're automatically "back clipping."
On another note, the aid climbing argument holds no water here due to the fact that while aid climbing, people often apply body weight to pieces that would never hold a fall.
-Mackley
Ps Is it that f'ing hard to use a runner?

Several years ago, just for my own "internet forum frustration release", I compiled a list of Ten Biggest Internet Climbing Misconceptions. Never Clip Metal To Metal was somewhere in the top three. I'll have to look and see if I kept that list.