Forums: Climbing Information: Beginners:
gate flutter
RSS FeedRSS Feeds for Beginners

Premier Sponsor:

 


halcyon


Jul 7, 2003, 9:52 PM
Post #1 of 12 (5449 views)
Shortcut

Registered: Jun 26, 2003
Posts: 227

gate flutter
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

Has anyone in here ever heard of a biner breaking in a fall or otherwise (other than testing) due to gate flutter? While I'm on the subject, has anyone ever heard of a biner breaking (other than testing)?


alpnclmbr1


Jul 7, 2003, 10:01 PM
Post #2 of 12 (5449 views)
Shortcut

Registered: Dec 9, 2002
Posts: 3060

Re: gate flutter [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

Saw a guy take a four footer and break a biner on a sport climb. If the gate opens from something they break pretty easily.
People setting slacklines break biners all the time.
A guy on this site broke a locker and the attached grigri on a aid solo fall.
As far as gate flutter and whiplash(two different things) there have been suspected cases for sure. But it is hard to prove the cause.


agentoffortune


Jul 7, 2003, 10:15 PM
Post #3 of 12 (5449 views)
Shortcut

Registered: Aug 12, 2002
Posts: 65

Re: gate flutter [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

I have seen one picture of a biner that broke due to this. But I don't know if the guy knew what he was talking about.


pico23


Jul 7, 2003, 10:29 PM
Post #4 of 12 (5449 views)
Shortcut

Registered: Mar 14, 2003
Posts: 2378

Re: gate flutter [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

In reply to:
Has anyone in here ever heard of a biner breaking in a fall or otherwise (other than testing) due to gate flutter? While I'm on the subject, has anyone ever heard of a biner breaking (other than testing)?

Standard gates flutter! WHen they do they reduce the biner strenght to less then 10kn which can break under a leader fall. Goran Kropp had broken biners in the fall that killed him. Open biners do fail.


darkside


Jul 8, 2003, 12:03 AM
Post #5 of 12 (5449 views)
Shortcut

Registered: Sep 14, 2001
Posts: 1687

Re: gate flutter [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

A few years ago I saw a top-roper slip off a climb. His rig was good and his belayer was paying attention. As he fell, the usual slack and the rope stretch allowed rope to run over the gate of the locking carabiner and unlock it. The rope tentioned and gate flutter allowed the rope to catch in the notch of the open biner gate. Fortunately there were two locking biners with gates correctly opposed, as one opened with the rope the other was being tightened. I noted the situation to the belayer, the climber lowered off and one of them went up and reset the biners.

This shows how forces in climbing can be complex and even apparently safe situations can become dangerous because of these forces. That is why redundancy is built into our systems. Don't imagine for an instant that freak things like this can't happen to you. Gate flutter is just one thing that can go wrong to compromise safety.

To explain gate flutter a little, imagine two lengths of webbing joined by a biner under tention. Now pull on this like a bow string. As the webbing twangs side to side, the biner changes direction. Inertia for anyone familiar with physics is where a body tries to resist change. As the biner comes to a stop, the gate may try to resist the stop and keep moving so it may open the gate. If this is as a leader is falling, the open gate may cause the biner to exceed it's open gate rating and fail. It has been surmised that this is part of the accident with Kropp. Another way to experience gate flutter is to simply take a biner and slap the spine on your knee or heel of your other hand. The snap you will hear is the gate opening and closing from inertia. This may be what alpnclmbr1 referred to as whiplash (usually from biner on rock) but unless I am mistaking his terminology, they are both inertia related.

The more mass a body has the more suseptible it is to inertia. This is why wiregates with less mass are less prone to gate flutter. Something for you to bear in mind.









i


alpnclmbr1


Jul 8, 2003, 12:35 AM
Post #6 of 12 (5449 views)
Shortcut

Registered: Dec 9, 2002
Posts: 3060

Re: gate flutter [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

nice post darkside

chris harmston wrote
In reply to:
How effectively do HotWires prevent "whiplash" (carabiner gate oscillation)?
Whiplash is a sudden opening of a rope-carrying carabiner's gate in
reaction to a sudden force, such as when the biner is loaded by a fall,
or if it slams against the rock. On very rare occasions, this
instantaneous opening of the gate can result in carabiner failure, if the
biner is loaded at the precise moment the gate is open. The low mass of
the HotWire's gate helps to eliminate whiplash, as does its stiff gate
action. By using high speed photography, we observed how HotWire gates
reacted to sudden forces. The wire gates proved to be much less
susceptible to whiplash movement, where conventional biner gates
oscillated substantially more.


alpnclmbr1


Jul 8, 2003, 12:51 AM
Post #7 of 12 (5449 views)
Shortcut

Registered: Dec 9, 2002
Posts: 3060

Re: gate flutter [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

In reply to:
Search Result 1From: Hank Moon (onkaluna@hotmail.com)
Subject: Re: I read on Gunks.com View: Complete Thread (17 articles)
Original FormatNewsgroups: rec.climbing
Date: 2001-10-06 09:45:17 PST

"hi" wrote in message news: > The primary reason you use a wiregate biner is to prevent gate
> whiplash which can cause the biner to open when loaded thereby
> weakening the biner. Gate whiplash occurs at the end of the draw
> clipped into the rope, so you want the wiregate on that end.

Hihi

In the interest of correcting a popular error in concept and syntax,
it should be noted that "whiplash" is not the same phenomenon as "gate
flutter." Whiplash refers to a peculiar behavior of rope that was
witnessed in laboratory drop tests conducted in Lyon, France in the
late 80's/early 90's (memory failing).

The tests were filmed with a high speed video camera in order to study
the affects on rope and 'biners in slomo. It was in these videos that
the "whiplash" phenomenon was observed: when the load released, the
rope would first drop down through the biner, then as the load fell,
reverse direction (now passing up through the biner). The slack rope
would then loop up high above the 'biner (up to 4 feet or so if memory
serves - haven't seen the videos in years) and finally "whip" against
the 'biner as the test load bottomed out. Quite frequently, the rope
would unclip itself from the 'biner as it did the whippin' thang.
Presumably, actual whiplash doesn't happen so much (if at all) in real
climbing due to mostly low fall factors, and friction between rope and
rock. True whiplash seems to be a high-FF lab phenomenon. You can
simulate whiplash at home with an anchored draw - doorknob works fine
- and accessory cord. Run the cord through the draw and give a swift
yank on one end to see the loop appear above the draw. Now imagine
much heavier cord and much, much, higher velocity and energy.

Gate flutter was also (first?) observed during these same tests, and
to my knowledge, has not been witnessed outside of a laboratory.
However, since we know it can happen in a lab, it has been suspected
as a possible cause of carabiner failure in the field. Keep in mind
there are many other such causes, most of which result in an open
gate: 'biner smacking rock, gate pushed open by rugosity, 'biner
loaded over edge, etc. True gate flutter results from vibrations
imparted to the carabiner from the rope moving rapidly through it. A
momentary opening of the gate due to the frame hitting rock, or sudden
loading/orienting of the draw is not gate flutter. The confusion of
the two concepts may have arisen due to gate openings observed when
the draw is suddenly loaded or "whipped". To finish off gate flutter,
it is important to note that carabiner failure during the tests
occurred so seldom that researchers resorted to taping the gates open
to induce failure. All failures occurred only in high-FF situations.

One result of these tests was an increase in the open gate strength
requirement of the UIAA standard. More info on gate flutter and other
topics of interest to climbers may be found at

http://www.uiaa.ch/journal/20003.pdf

Be sure to check out the article on page 4, "Karabiner Breakings when
Using a Figure-of-Eight." Unfortunately, this type of stuff is rarely
reported in the US climbing press, articles by Clyde Soles being the
most notable exception. Guess Usenet forms a limited alternative
"press" of sorts. Thank E.M. for rec.climbing, and pardon the thread
pirating.

Hank

> opinions are mine, not my employer's <


pico23


Jul 8, 2003, 11:52 AM
Post #8 of 12 (5449 views)
Shortcut

Registered: Mar 14, 2003
Posts: 2378

Re: gate flutter [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

[quote="alpnclmbr1"]
In reply to:
Search Result 1From: Hank Moon (onkaluna@hotmail.com)
Subject: Re: I read on Gunks.com View: Complete Thread (17 articles)
Original FormatNewsgroups: rec.climbing
Date: 2001-10-06 09:45:17 PST

"hi" wrote in message news: > The primary reason you use a wiregate biner is to prevent gate
> whiplash which can cause the biner to open when loaded thereby
> weakening the biner. Gate whiplash occurs at the end of the draw
> clipped into the rope, so you want the wiregate on that end.

Hihi

In the interest of correcting a popular error in concept and syntax,
it should be noted that "whiplash" is not the same phenomenon as "gate
flutter." Whiplash refers to a peculiar behavior of rope that was
witnessed in laboratory drop tests conducted in Lyon, France in the
late 80's/early 90's (memory failing).

Thanks for defining the two. I think most of us use the terms interchangably. In either case wire gates cut down on both whiplash and flutter (if I am reading correctly).


deadfish


Jul 8, 2003, 12:42 PM
Post #9 of 12 (5449 views)
Shortcut

Registered: Apr 4, 2003
Posts: 57

Re: gate flutter [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

In reply to:
Thanks for defining the two. I think most of us use the terms interchangably. In either case wire gates cut down on both whiplash and flutter (if I am reading correctly).

To be completely semantically clear...wire gates cut down on flutter and inertial opening (caused by smacking a biner against the rock). Whiplash is a rope phenomenon, doesn't have to do really with the particular biner in use. The likelihood of unclipping due to whiplash, however, may increase with certain biner designs (notably bent gates, because of the gate shape). The likelihood of unclipping due to whiplash is probably pretty damn small, though. I wouldn't lose sleep over it. Much more likely to fail a biner by loading it in an open configuration, and this is much more likely to happen by being forced open against a rock than through flutter and/or inertia.

But I use wire gates anyway. They are strong and light and make me happy.


alpinerockfiend


Jul 8, 2003, 1:37 PM
Post #10 of 12 (5449 views)
Shortcut

Registered: Feb 2, 2003
Posts: 598

Re: gate flutter [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

In reply to:
Standard gates flutter! WHen they do they reduce the biner strenght to less then 10kn which can break under a leader fall. Goran Kropp had broken biners in the fall that killed him. Open biners do fail.

I thought Kropp's pro pulled out!


pico23


Jul 8, 2003, 1:57 PM
Post #11 of 12 (5449 views)
Shortcut

Registered: Mar 14, 2003
Posts: 2378

Re: gate flutter [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

In reply to:
In reply to:
Standard gates flutter! WHen they do they reduce the biner strenght to less then 10kn which can break under a leader fall. Goran Kropp had broken biners in the fall that killed him. Open biners do fail.

I thought Kropp's pro pulled out!

I might be wrong but I think the final report I read was that they really didn't know but they thought a few things happened. 1) a biner broke 2) zippering happened (although the zippering was below where the last piece that held was so it wasn't an issue) and 3) the remaining gear was shockloaded. A lot of pieces in the system failed almost like if they were using a static rope. However, the rope they used was in fact dynamic.

What I took from the reports was that the first piece failed (was this the piece the biner that failed was on??) and didn't give the rope enough time to regain elasticity and then it shockloaded the remaining gear. What I learned from it was not to place marginal "just in case" gear so as to avoid shock loading the good gear.


alpinerockfiend


Jul 8, 2003, 2:06 PM
Post #12 of 12 (5449 views)
Shortcut

Registered: Feb 2, 2003
Posts: 598

Re: gate flutter [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

Thanks.


Forums : Climbing Information : Beginners

 


Search for (options)

Log In:

Username:
Password: Remember me:

Go Register
Go Lost Password?



Follow us on Twiter Become a Fan on Facebook