הצגת המקור של הדף "ההתכתבות בנושא טבעות לא ננעלות ואמצעי חיכוך כן"

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hi

i've stumbled on your "The Climbing Mythbusters" page, and liked
most
of it, and to most of it i agree.

i'd like to raise one question, however, about auto locking devices
used with non-locking biners.

first, i'll introduce myself. my name is Micha Yaniv. i've been
climbing for 20 years, and have been a mountain guide for 16 out of
them.
I climbed many season, routes and summits and in the alps, as
well as
in Peru and summited Everest on 2006
i ran a many climbing courses, quite a few guides courses, for
climbing guides, mountain guides and canyoning guides. I am a senior
guide of the IDF climbing and rescue school. also, i ran numerous
experiments over the years, on knots, pieces of gear as well as on
large rescue systems.

i have a BSc in physics and Math, MSc in Ecology, and am working on
my PhD in Geophysics. i think i have pretty good understanding of
how
most pieces of gear work, and of most things that should be taken
into account when analising climbing situations.

also, i have been working on an extensive "climbing
encyclopedia" (it
can be found here: wiki.imga.org.il) but it is in Hebrew, so i
guess,
not very interesting to you...

I am just writing this, to let you know i am not just objecting to
your statement about belaying with a non-locking biner, but i truly
fail to see the importance, and have some experience to back it up.

ok, the main question is: how is this any different from using a
rack
as a belay device? or a brakebar with a piton or ice-screw as the
bar? all those cases are improvisations, and are not considered
common practice, of course, but in essence, they are ok to use.

it is clear to me that there is no risk of the a non-locking biner
braking when used like this. only reason not to use one, is that the
rope may unclip itself. what are the chances of that happening? i've
been using many devices over the years and have never seen anything
like that happen. of course, this is no proof that it cannot happen,
but has it ever happened?

i asked all my friends and ran a search, and could not find a singe
case it happened. again, maybe not good enough. ok, let's try to
think about it:
as long as there is minimal load on the device, the rope cannot
unclip itself. more even: the binner cannot even turn or flip, so
that the gate becomes closer to the loop of rope. now, the loop of
rope should be large enough to pass over the gate. that should be
easy for a pretty rigid rope, such as old static ropes or ropes that
have bad knotability. with dynamic ropes, and especially thin
dynamic
ropes, such as commonly used for long routes (double and twin
ropes),
i think that this risk is negligible.

i do not object to using a locking biner for belaying with an auto-
locking device, of course, but i would not strongly claim that using
non- locking biners is very bad pactice ande extremely dangerous.

i am fully aware to the fact that i might be missing somethibng, and
i'd be glad to hear your thoughts,

Mica Yaniv
Middle East Mountain Guides
office:00-972-2-6586194
cell: 00-972-54-7625243
www.memg.co.il



hello mica,

thank you for your reply regarding my website.  i am honored that
someone
of your experience has read through my page and took such time to
think
through it.  it is truly wonderful to engage such an experienced and
bright person.

i agree that it is highly unlikely that the rope will become
unclipped
from the nonlocking carabiner when used to retain the rope in a
reverso,
guide atc, or other plaquette device.  i also agree that i have
found no
documented cases in which this has occurred specifically with a
plaquette
device.  while i recognized the sheer improbablity of this, i
wrote this
article as it appears on my website for a couple of reasons:

1) the vast majority of people that read through my site have less
than a
tenth of the experience and knowledge that you have.  as a basic
principle, i felt that it was important to stress the idea that if
one's
life is dependent upon a single carabiner, it should be a locking
carabiner.  if i were to propose the idea that use of a nonlocker
is safe
here (and under the watchful eye of an experienced mountain guide
i'm sure
it is), less experienced climbers might also deduce that it is
acceptable
to use a single nonlocking carabiner to rappel with, to tie in
with, or to
use for a redirected top rope.

2) while i again agree that it is highly unlikely that the rope could
become unclipped from a nonlocking carabiner used in a plaquette,
clearly
the probability of the rope becoming unclipped is less likely when
using a
locker.  while there have been no reported cases where this has
happened
with a plaqette in autolocking mode, there have been cases where
nonlockers have come unclipped from the top piece during a lead fall,
during rappels, and cases where nonlockers have unclipped from bolts
during traverses.  (i myself witnessed the latter happen).  i have
also
read a documented cases where an autolocking carabiner came unclipped
during a rappel, leading to a catastrophic fall.  while i agree
that these
cases involve much more relative movement between the rope and the
carabiner, it suggests to me that use of a locker in the plaqette
device
may prevent an unforeseen accident.  again, this applies to the
novice and
intermediate user.

i do think, however, that your comments completely valid.  it
would be
interesting to set up a mechanical simulation with thousands of
falls to
see if a nonlocker ever becomes unclipped.

on another note, i would be interested in your comments on the
article i
have posted on my website regarding gear selection.  you can
download the
article from my website at www.geir.com/Article.doc.

respectfully,

geir hundal




hi geir

hi geir

thank you for a quick and detaile reply. i'll be glad to look
through your article. i'll let you know what i think.

now, to answer to your arguments:

1 and actually, 2, so i'll regard them combined, with your
permission. it is also my opinion that one should write, aiming at
the unexperienced rather than the experts. but in stating something
as an expert, you might think that beginners will take it as is,
rather than think about it.
since you agree, in general, that it is highly improbable (i would
put it more strongly - probably impossible) for a rope to unclip
itself from an auto-locking belay device, i fail to see how it is
connected with another general case of using a locking biner as a
rule, when rappeling or belaying. the main reason to use a locking
biner, is not that the rope may unclip itself, but that the biner
might open. when the gate is open, the biner is roughly 2/3 it's
designated strength. with a lightweight, old, worn, and possibly
damaged biner, this can become a hazard. i actually know of one
case where a supposedly good biner (it was not damaged or worn in
any way visible) broke under a load of one person when opened while
it was loaded. i was usked to give an expert statement in court
about this case).

so, it is actually more important to use a locking biner to attach
your plaquette to the anchor than to use one on the ropes. the risk
of the rope biner opening makes it no more dangerous, because it is
no used as a biner at all! it is used as a bar. ans as such, the
strength of the biner has no relevance.

so, my point is, that the case is different.

as i see it, there are three categories of cases:

1. when the rope is not loaded part of the time, like rope running
through runners, top-rope with some slack etc. the rope can clip
itself, and if you just one point (like in top-rope, both with the
belayer and on the anchor), do anything in your power to prevent
the opening of the gate, like use a non- locking biner. if you
cannot, as while leading, avoid back-clipping to reduce that risk.

2. you have one point of attachment, and that point is a biner and
it's loaded. in this case, the thing to avoid is the hazard of the
biner breaking if the gate opens. this applies to high load systems
like rescue systems, omega lines etc. but also when rapping or
swinging on a pendulum traverse. in this case, you want to use a
non-locking biner, but not to avoid unclipping, but to avoid the
relative weakening of the biner that happens with the gate opening.

3. the third case is what we're interested in. you use the spine of
the biner as a bar. the biner can be broken, it can be open, it can
be a rod or a tube of metal [like an ice-screw or a piton, or a bar
taken off a brake-bar (Petzl Rack, for example)]. since the rope
going through the belay device, and therefore the biner is partly
loaded (minimum load is the weight of rope below the anchor), the
risk of unclipping is negligible.

no, it is not that i have an objection to using locking biners in
this case, i just think it is a non-issue. while not having much
direct effect on safety, it does have a negative effect on safety,
indirectly. if you pay attention to only using a locking biner at
the anchor, it means you have an extra locking biner, and cannot
use one of your runners or free biners. if it takes a little more
time pinpoint that one biner in your rack, it means you spend more
time on that, and you are slower at setting your belay and slower
on the route in general. it seams like a small price to pay for a
possible improvement of ones safety, but i think it goes deeper
that just that.

it seems to me that the main thing that you are saying is: always
use a locking biner. the exact situation is not important, just use
locking biners. the beginners that read your site might take it
like that. i would think that in this case, it is not as simple as
that, and that it's better to teach people the reasons why this
case is different than others.

two more things. i would thing that when people get to the point of
using auto-locking devices, they are not novices anymore. this is
my recommendation in general. someone would use that kind of gear
only when they get to the point of multi-pitch, maybe trad,
probably twin or double rope leading. therefore, it is ok to let
them know of the subtlety of the situation.

lastly, i'd like to say that i might be wrong. there may be a case
in the future, when a rope unclips itself in exactly the same
situation. i am in no way too arrogant to avoid acknowledgment of
that possibility. even tough, i will continue teaching people
according to what i know. this way, i believe they will be aware of
the difference, and they will pay attention to having the rope
loaded at all times, so it cannot unclip itself even if it wants
too very badly...

mica

PS. my cow's tail for the everest climb had one, lightweight, non-
locking bine. this was a decision, of course, not chance. the use
of locking biners with thick mittens is too time consuming, as well
as the use of two biners, not to mention the weight. so, i follow
my own advice, usually.

cheers

Mica Yaniv
Middle East Mountain Guides
office:00-972-2-6586194
cell: 00-972-54-7625243
www.memg.co.il

hello mica-

good to hear back from you.  first, thanks for reading my article
and your kind comments.  i will take your comments into account as
i revise the article and software.

now to answer your comments regarding our discussion of nonlocking
carabiners, particularly with respect to their use in plaquette
devices:

1)  while i have not read the black diamond study conducted on
dropped carabiners, i read (and have a copy of) a similar study
carried out by rei.  interestingly, dropped carabiners were also
slightly stronger than their non-dropped counterparts.  i will
request a copy of black diamond's study and revise my carabiner
strength notes accordingly.

2)  regarding this paragraph:

since you agree, in general, that it is highly improbable (i would
put it more strongly - probably impossible) for a rope to unclip
itself from an auto-locking belay device, i fail to see how it is
connected with another general case of using a locking biner as a
rule, when rappeling or belaying. the main reason to use a locking
biner, is not that the rope may unclip itself, but that the biner
might open. when the gate is open, the biner is roughly 2/3 it's
designated strength. with an lightweight, old, worn, and possibly
damaged biner, this can become a hazard. i actually know of one
case where a supposedly good biner (it was not damaged or worn in
any way visible) broke under a load of one person when opened while
it was loaded. i was usked to give an expert statement in court
about this case).

so, it is actually more important to use a locking biner to attach
your plaquette to the anchor than to use one on the ropes. the risk
of the rope biner opening makes it no more dangerous, because it is
no used as a biner at all! it is used as a bar. ans as such, the
strength of the biner has no relevance.

we have a difference in opinion here.  the main point i stress in
teaching about locking vs nonlocking carabiners is that a locker
should be used any time a person's life/safety is dependant upon a
single carabiner.  this includes while rappelling with a tuber,
belaying a leader with a tuber device, attaching to an anchor
point, and to hold the ropes in the plaquette device.  in my
thinking, reduction of the liklihood of a rope becoming unclipped
is just as important as maintaining a closed gate for carabiner
strength.

i suspect that a greater number of accidents occur from ropes
becoming unclipped than from failure of carabiners due to strength
reduction when gaits open.  although i fully admit this is just a
guess on my part, and have not yet done research to conclusively
know this.  in my personal experience (which is not as extensive as
yours) i have seen ropes become unclipped three times, but have not
witnessed a carabiner failure due to an open gate.

i do agree with you that it is unlikely that a nonlocker, used as a
bar in a plaquette, is surely strong enough regardless of whether
its gate is open or not.  in pull tests that i have observed, rope
failure always occurred before carabiner failure when a plaquette
is pulled to failure.

i'm not fully convinced that the contant tension exerted on a
nonlocker in a plaquette is sufficient to prevent rotation and
possible unclipping (although it is very unlikely).  i will send a
series of photos to demonstrate what i have in mind, although i
cannot send them to you right now as i'm in an aircraft, and i
don't think the stewardesses will allow me to set up and photograph
what i have in mind.  i'll send more on this after i've returned home.

3) regarding these paragraphs:

as i see it, there are three categories of cases:

1. when the rope is not loaded part of the time, like rope running
through runners, top-rope with some slack etc. the rope can clip
itself, and if you just one point (like in top-rope, both with the
belayer and on the anchor), do anything in your power to prevent
the opening of the gate, likk use a nomn- locking biner. if you
cannot, as while leading, avoid back-clipping to reduce that risk.

2. you have one point of attachment, and that point is a biner and
it's loaded. in this case, the thing to avoid is the hazard of the
biner breaking if the gate opens. this applies to high load systems
like rescue systems, omega lines etc. but also when rapping or
swinging on a pendulum traverse. in this case, you want to use a
non-locking biner, but not to avoid unclipping, but to avoid the
relative weakening of the biner that happens with the gate opening.

3. the third case is what we're interested in. you use the spine of
the biner as a bar. the biner can be broken, it can be open, it can
be a rod or a tube of metal [like an ice-screw or a piton, or a bar
taken off a brake-bar (Petzl Rack, for example)]. since the rope
going through the belay device, and therefore the biner is partly
loaded (minimum load is the weight of rope below the anchor), the
risk of unclipping is negligible.

clearly, your experience level and manner of explanation are both
excellent.  i agree with everything above, except that i would add
again that i equally value the two major advantages of locking
carabiners, namely the decreased risk of unclipping and the
decreased of strength reduction due to accidental gait opening.

4)  regarding this paragraph:

it seems to me that the main thing that you are saying is: always
use a locking biner. the exact situation is not important, just use
locking biners. the beginners that read your site might take it
like that. i would think that in this case, it is not as simple as
that, and that it's better to teach people the reasons why this
case is different than others.

as i mentioned above, my feeling is that a locker should be used if
it is the only carabiner in the system assuring a person's safety.
in all other cases, a nonlocker is an excellent choice.  my
thinking here is a result of both personal experience and the
instruction i recieved in my own certification courses.  although i
also think that an expert has the experience and judgment to vary
from this line of thought, and will certainly be making a valid
judgement.  i just feel this is a simple rule to teach by.

5)  regarding this paragraph:

lastly, i'd like to say that i might be wrong. there may be a case
in the future, when a rope unclips itself in exactly the same
situation. i am in no way too arrogant to avoid acknowledgment of
that possibility. even tough, i will continue teaching people
according to what i know. this way, i believe they will be aware of
the difference, and they will pay attention to having the rope
loaded at all times, so it cannot unclip itself even if it wants
too very badly...

i would also like to admit that my line of thinking may prove to be
wrong.  clearly you are an exceptionally experienced guide and a
quite intelligent person.  i respect your honesty and thoughtful
approach to guiding.


on a different note, i noticed you climbed everest!  fantastic!
did you summit?

respectfully,
geir hundal


oh, and about the binners.
i tried o find the BD experiment on the web but could not. it was in
climbing magazine some years ago.
but that might interest you/:
i talked to this expert in Metalurgy some time ago, and asked him
about the binners. he said that:
1. in few cases, the biner may even become stronger.
2. in most cases, nothing will change.
3. in a few cases it may fracture and become substantially weaker.

the percentages depend on the batch size, repeatability, stability of
manufacture conditions and quality control. oh, and the quality of
the raw material they start with.

his recommendation was: if it's not extremely expensive (which
binners aren't), scrap it if it falls.



מיכה יניב
מדריכי הטיפוס של המזרח התיכון

בבית: 02-5346344
במשרד: 02-6586194
בנייד: 054-7625243

בקרו באתר שלנו:
www.memg.co.il


great - thanks for the info.  i'll contact BD directly some time after i
return from my climbing trip...

sincerely,
geir
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