Biner to biner to biner to biner.....?

Biner to biner to biner to biner.....?

Post by Juli » Wed, 18 Oct 2000 04:00:00


Here's another running debate (for me anyways):

Do you clip biners in series (i.e., linking draws together, or clipping
a draw to the biner on a piece)?

I've seen enough people do this (34 stories omitted) to make me question
my own rejection of its safety.

I think the physics argument would go something along the lines of
metal-to-metal contact concentrating all the transmitted force at one
very small point, and in one very particular direction;  whereas slings
absorb and then dissipate the same force as they pull on a biner,
allowing for more directional adjustements as well.
I've also heard things about gates being forced open.

Please donate your $0.02 here.


 
 
 

Biner to biner to biner to biner.....?

Post by Bernd Nebendah » Wed, 18 Oct 2000 04:00:00

Quote:
>I've seen enough people do this (34 stories omitted) to make me question
>my own rejection of its safety.

>I think the physics argument would go something along the lines of
>metal-to-metal contact concentrating all the transmitted force at one
>very small point, and in one very particular direction;  whereas slings
>absorb and then dissipate the same force as they pull on a biner,
>allowing for more directional adjustements as well.
>I've also heard things about gates being forced open.

The standard procedure for testing biners uses a test setup, where the
biner is loaded via a rigid circular rod of defined diameter (approx 20 mm,
correct me if I'm wrong). Therefor the ratings found on the biner include
the above described effect of point forces. Additionally, if a biner would
not be able to withstand those forces, it would not be possible to clip any
bolt.

Another point regarding the words "absorb" and "dissipate". Force is not
absorberd or dissipated by the sling it's only distributed over a larger
area.
Actually a wide sling loads the biner in a more critical way than a narrow
sling,
that's btw the reason why e.g. Petzl introduced their runners with narrower
biner ends.

About gate opening. I don't see any mechanism, that is introduced by
clipping
a biner to a biner, which adds to the well known gate opening problems, e.g.
gates
forced open by contact to rock and whiplash.

Bernd

 
 
 

Biner to biner to biner to biner.....?

Post by James Staple » Wed, 18 Oct 2000 04:00:00

Although it would be a rare situation, two biners can unclip themselves.
Why take that risk if you don't have to?

 
 
 

Biner to biner to biner to biner.....?

Post by Jeremy the Sumo Climbe » Wed, 18 Oct 2000 04:00:00



Quote:
> Here's another running debate (for me anyways):

> Do you clip biners in series (i.e., linking draws together, or
clipping
> a draw to the biner on a piece)?

> I've seen enough people do this (34 stories omitted) to make me
question
> my own rejection of its safety.

> I think the physics argument would go something along the lines of
> metal-to-metal contact concentrating all the transmitted force at one
> very small point, and in one very particular direction;

Bollocks. At least that was the consensus a few months ago when some
overbearing schmuck insisted that was the case.

Quote:
> whereas slings
> absorb and then dissipate the same force as they pull on a biner,
> allowing for more directional adjustements as well.
> I've also heard things about gates being forced open.

The issue is that biners chained together will rather easily unclip
themselves.

Quote:
> Please donate your $0.02 here.

That'll be $10,000 for engineering services.

 - Sumo

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Biner to biner to biner to biner.....?

Post by Keith Jewel » Wed, 18 Oct 2000 04:00:00

Quote:

>> Do you clip biners in series (i.e., linking draws together, or
clipping
> a draw to the biner on a piece)?

Not if I can help it.  I worry about the possible unclipping from two
rigid biners twisting around together.

Quote:
> I think the physics argument would go something along the lines of
> metal-to-metal contact concentrating all the transmitted force at one
> very small point, and in one very particular direction;  whereas
slings
> absorb and then dissipate the same force as they pull on a biner,
> allowing for more directional adjustements as well.

I don't buy that arguement at all.  When chaining draws, the sling
absorbs the same amount of force that it would if only one draw were
used.  As far as "metal-to-metal contact", think about the very small
radius of a bolt hanger in comparison to the biner radius.  Nobody seems
to worry about the problem in that situation.  The easier unclipping
arguement is valid, in my opinion.  Play with two biners and see for
yourself.

K

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Biner to biner to biner to biner.....?

Post by Juli » Wed, 18 Oct 2000 04:00:00

Quote:
> Additionally, if a biner would not be able to withstand those forces, it would
> not be possible to clip any bolt.

True;  but minimizing the number of those pinpointed forces would be a good
thing, no?  Also, a bolt doesn't move around.

Quote:
> Force is not absorberd or dissipated by the sling it's only distributed over a
> larger
> area.

That was (one of ) the point in using a sling (!), I thought....

Quote:
> Actually a wide sling loads the biner in a more critical way than a narrow
> sling

Explain?  Wouldn't a rope do the same?

Quote:
> About gate opening. I don't see any mechanism, that is introduced by
> clipping a biner to a biner

Clip two together, head-to-head.  Now, twist & shout.....

JSH

 
 
 

Biner to biner to biner to biner.....?

Post by Dave Hil » Wed, 18 Oct 2000 04:00:00


Quote:
> As far as "metal-to-metal contact", think about the very small
> radius of a bolt hanger in comparison to the biner radius.  Nobody seems
> to worry about the problem in that situation.

I never did, until I took a look at our haul biner after climbing El Cap.
There was a major groove worn into it.  That biner quickly became my shoe
biner!

Dave.

 
 
 

Biner to biner to biner to biner.....?

Post by Chris Wegene » Wed, 18 Oct 2000 04:00:00


Quote:
> Here's another running debate (for me anyways):

> Do you clip biners in series (i.e., linking draws together, or clipping
> a draw to the biner on a piece)?

><snip of incorrect speculation on why biners in a series are bad>

The reason this is a bad idea is easy to demonstrate.  Clip two biners
together and twist one biner over the gate of the other.  You will see that
the biners easily unclip themselves.  If the climber crosses over a piece
with two biners in series and falls the biners unclip themselves and there
is no pro.

If you want to clip a quick draw into a piece clip it into the sling
directly.

--
Chris

-- this is for the SPAMMERS robots

 
 
 

Biner to biner to biner to biner.....?

Post by Brutus of Wyd » Wed, 18 Oct 2000 04:00:00

Quote:

> > As far as "metal-to-metal contact", think about the very small
> > radius of a bolt hanger in comparison to the biner radius.  Nobody
> > seems to worry about the problem in that situation.

And Dave Hill responded:

Quote:
> I never did, until I took a look at our haul biner after climbing El
> Cap. There was a major groove worn into it.  That biner quickly
> became my shoe biner!

I also have retired numerous carabiners due to bolt-hanger grooves.
The issue is not a sudden break of a new carabiner due to this
concentration of force, but rather wear repeated over time, gradually
weakening the carabiner. And this becomes a significant problem when
the carabiner is repeatedly loaded, to twice the weight of the haul
bag or more, with small shifts in direction of loading, such as when
hauling, or suspending a portaledge carrying two chubbies.

And yes, I agree that torsion applied to chained carabiners is the
bigger issue. Hanger wear is easily mitigated by inspecting on a
routine basis, something we should do anyways...

Brutus

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Biner to biner to biner to biner.....?

Post by Bob » Wed, 18 Oct 2000 04:00:00

Quote:
> Do you clip biners in series (i.e., linking draws together, or clipping
> a draw to the biner on a piece)?

Forget about forces for a minute.

The problem as it's been described to me is when you clip more than 1 biner
in series to a wired stopper. The lack of something that is able to twist in
between them (ie. sling) can lead to a higher possibility that the stopper
could dislodge itself as the biners rotate. This would not be the case for a
cam or other pro on a more flexible sling.

Just my $0.02

-Bob

 
 
 

Biner to biner to biner to biner.....?

Post by Mike Garriso » Wed, 18 Oct 2000 04:00:00

Quote:

> Do you clip biners in series (i.e., linking draws together, or clipping
> a draw to the biner on a piece)?

It happens.

The danger (as others have pointed out) is that biners can
unclip themselves. No one in this thread has explained how,
so I will just in case you've never seen it happen.

When you twist the biner chain (in torsion) the biners ride
up the spines of each other. Eventually they get to the
gates, which unclip. Locking biners will pretty much
eliminate this hazard.

Try it at home.

When the biners are not being twisted, they are fairly safe.

But given a choice, I'd rather connect things with slings
than biner chains.

-Mike

 
 
 

Biner to biner to biner to biner.....?

Post by maddog.. » Wed, 18 Oct 2000 04:00:00

Quote:

>Here's another running debate (for me anyways):
>Do you clip biners in series...?

A few years ago, we worked this thread to death.  I thought the best
part of it was the "Clipping Beer to Biner" spinoff.

Mad 'chug'em if ya gottem' Dog

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Biner to biner to biner to biner.....?

Post by Geoff Jennin » Thu, 19 Oct 2000 14:41:07

Quote:

> Also, a bolt doesn't move around.

Obviously someone who hasn't climbed much outside of super-popular sport
climbing areas....I think I clipped more 1/4 inch spinners this summer than 1/2
solid bolts....=>
Geoff
 
 
 

Biner to biner to biner to biner.....?

Post by Juli » Thu, 19 Oct 2000 04:00:00

Quote:
> > Also, a bolt doesn't move around.

> Obviously someone who hasn't climbed much outside of super-popular sport
> climbing areas....I think I clipped more 1/4 inch spinners this summer than 1/2
> solid bolts....=>

Geoff, I enjoyed your flame of Adrian this morning, but please, go have a cup of
coffee, on me, eh?

Insert the word 'usually' in there, and add all the footnoted expeptions at
will....

JSH 'not a lawyer, nor do I play one on TV'