Forums: Climbing Information: The Lab:
Video: Testing FF2 with dyneema
RSS FeedRSS Feeds for The Lab

Premier Sponsor:

 
First page Previous page 1 2 3 Next page Last page  View All


jliungman


Dec 19, 2012, 1:28 AM
Post #1 of 64 (7504 views)
Shortcut

Registered: Dec 19, 2012
Posts: 7

Video: Testing FF2 with dyneema
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

Hi!

I have received video material from some friends and experienced climbing instructors, showing some fairly alarming results concerning the use of knotted dyneema.

http://vimeo.com/41522053

I apologize for the fact that commentary is in Swedish. Ive uploaded two doodles to try and explain whats going on. (EDIT: Note that this is NOT a static fall, the rope used is DYNAMIC. The rope is tied to the dummy, and to the carabiner shown at the bottom of each sketch.)

The results, in short, show that under heavy but entirely realistic loads (ff 2 with new rope and and test dummy), a new dyneema sling fails completely. This happens when the dyneema is shortened using two techniques which, at least in Scandinavia, are common and taught by instructors.
Any thoughts? To me the results imply that we should avoid knotting dyneema altogether, and use this fantastic material only in full length, stitched slings (like quick draws). At least until we know more about which nylon/dyneema/widths/knots combinations work and which dont.


(This post was edited by jliungman on Dec 19, 2012, 12:29 PM)
Attachments: Attachment001.png (56.7 KB)
  Attachment002.png (60.3 KB)


iknowfear


Dec 19, 2012, 2:44 AM
Post #2 of 64 (7489 views)
Shortcut

Registered: Sep 8, 2004
Posts: 637

Re: [jliungman] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

jliungman wrote:
Hi!

I have received video material from some friends and experienced climbing instructors, showing some fairly alarming results concerning the use of knotted dyneema.

http://vimeo.com/41522053

I apologize for the fact that commentary is in Swedish. Ive uploaded two doodles to try and explain whats going on.

The results, in short, show that under heavy but entirely realistic loads (ff 2 with new rope and and test dummy), a new dyneema sling fails completely. This happens when the dyneema is shortened using two techniques which, at least in Scandinavia, are common and taught by instructors.
Any thoughts? To me the results imply that we should avoid knotting dyneema altogether, and use this fantastic material only in full length, stitched slings (like quick draws). At least until we know more about which nylon/dyneema/widths/knots combinations work and which dont.

thanks.

http://dmmclimbing.com/...notting-dyneema-vid/

this can be summed up:
Don't fall on static stuff.

regarding this:
In reply to:
ff 2 with new rope and and test dummy

I can't think of a situation in which a rope is relevant here... do you mean new sling?


(This post was edited by iknowfear on Dec 19, 2012, 2:45 AM)


USnavy


Dec 19, 2012, 3:10 AM
Post #3 of 64 (7482 views)
Shortcut

Registered: Nov 5, 2007
Posts: 2657

Re: [jliungman] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (1 rating)  
Can't Post

jliungman wrote:
Hi!

I have received video material from some friends and experienced climbing instructors, showing some fairly alarming results concerning the use of knotted dyneema.

http://vimeo.com/41522053

I apologize for the fact that commentary is in Swedish. Ive uploaded two doodles to try and explain whats going on.

The results, in short, show that under heavy but entirely realistic loads (ff 2 with new rope and and test dummy), a new dyneema sling fails completely. This happens when the dyneema is shortened using two techniques which, at least in Scandinavia, are common and taught by instructors.
Any thoughts? To me the results imply that we should avoid knotting dyneema altogether, and use this fantastic material only in full length, stitched slings (like quick draws). At least until we know more about which nylon/dyneema/widths/knots combinations work and which dont.
Cool video, but this is not new news, we have known about this forever. Also, it is best not to tie knots in Dyneema slings for a number of reasons.


(This post was edited by USnavy on Dec 19, 2012, 3:11 AM)


njrox


Dec 19, 2012, 6:50 AM
Post #4 of 64 (7430 views)
Shortcut

Registered: May 12, 2011
Posts: 251

Re: [jliungman] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

jliungman wrote:
To me the results imply that we should avoid knotting dyneema altogether, and use this fantastic material only in full length, stitched slings (like quick draws).

Yep. I only use dyneema for sling-draws and never knot it.


jliungman


Dec 19, 2012, 11:33 AM
Post #5 of 64 (7359 views)
Shortcut

Registered: Dec 19, 2012
Posts: 7

Re: [iknowfear] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

iknowfear wrote:

this can be summed up:
Don't fall on static stuff.

regarding this:
In reply to:
ff 2 with new rope and and test dummy

I can't think of a situation in which a rope is relevant here... do you mean new sling?

Its highly relevant, since, as I said, it is a realistic factor two fall on a dynamic rope, NOT a static fall as in the DMM video. The rope is connected to the dummy, and runs through the bottom carabiner seen in the doodles I attached.

I do not agree that this is all well known stuff. There has been speculation and opinion, but I have yet to see anything but a half-hearted warning from the manufacturers. Most people I know, including quite a few highly skilled instructors and rope access people, use the dyneema just like theyd use the nylon sling.


Partner cracklover


Dec 19, 2012, 1:09 PM
Post #6 of 64 (7320 views)
Shortcut

Registered: Nov 14, 2002
Posts: 9967

Re: [jliungman] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

jliungman wrote:
iknowfear wrote:

this can be summed up:
Don't fall on static stuff.

regarding this:
In reply to:
ff 2 with new rope and and test dummy

I can't think of a situation in which a rope is relevant here... do you mean new sling?

Its highly relevant, since, as I said, it is a realistic factor two fall on a dynamic rope, NOT a static fall as in the DMM video. The rope is connected to the dummy, and runs through the bottom carabiner seen in the doodles I attached.

I do not agree that this is all well known stuff. There has been speculation and opinion, but I have yet to see anything but a half-hearted warning from the manufacturers. Most people I know, including quite a few highly skilled instructors and rope access people, use the dyneema just like theyd use the nylon sling.

Yes, that's right. Most folks have been saying something along the lines of "So long as the rope is in the system, that should limit the force and the dyneema will be fine". Now we know that, at least in some cases, that is not so.

Now a question for you - in the video you linked, it appears that there are two tests, and the sling fails in the first, but not in the second. I gather that the talking (in Swedish) after the second test, while pointing at points on the sling, is saying something like "here, here, and here, the sling is damaged." Is that what happened?

GO


sittingduck


Dec 19, 2012, 1:58 PM
Post #7 of 64 (7303 views)
Shortcut

Registered: Aug 19, 2003
Posts: 338

Re: [cracklover] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

cracklover wrote:
I gather that the talking (in Swedish) after the second test, while pointing at points on the sling, is saying something like "here, here, and here, the sling is damaged." Is that what happened?

GO

The sling was shortened by an overhand knot and both carabiners where clipped in the same loop.
He said that the overhand knot slid until it stopped at the sewing of the sling.

He could see no damage but said that the air was full of fibers floating around.

That is a super makeshift screamer :)


Partner cracklover


Dec 19, 2012, 2:13 PM
Post #8 of 64 (7291 views)
Shortcut

Registered: Nov 14, 2002
Posts: 9967

Re: [sittingduck] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

Hmmm... so maybe the OP could explain what he (she?) means about both methods failing?

GO


redlude97


Dec 19, 2012, 2:16 PM
Post #9 of 64 (7286 views)
Shortcut

Registered: Aug 27, 2008
Posts: 988

Re: [cracklover] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

It seems like in the first test and your diagram, the slack in the leg without a knot causes the force to be put on only 1 strand of the sling with the knot in it, is that correct?


(This post was edited by redlude97 on Dec 19, 2012, 2:17 PM)


sittingduck


Dec 19, 2012, 3:21 PM
Post #10 of 64 (7258 views)
Shortcut

Registered: Aug 19, 2003
Posts: 338

Re: [cracklover] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

cracklover wrote:
Hmmm... so maybe the OP could explain what he (she?) means about both methods failing?

GO

At the end of the video the text says that drop nr. 2 also was performed with a nylon sling and then the overhand knot only walked 5 cm (2 inches). Maybe the criteria for success was for the overhand not to walk?

To me it looked like a success, will use it on ice :)


bearbreeder


Dec 19, 2012, 3:50 PM
Post #11 of 64 (7244 views)
Shortcut

Registered: Feb 1, 2009
Posts: 1960

Re: [jliungman] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

interesting ... but where is the belay device?

for it to be a realistic you need a belay device ...

the other interesting thing is that the guy at the end goes totally hands free on a gri gri with no backups when inspecting the sling ... which is likely more dangerous over time than the very rare occurrence of a true FF2 fall on dyneema ...

which i think goes to show the "fear" people have of dyneema ... vs the everyday hands free use of a gri gri or other such which is much more likely IMO of killing you ...

theres a focus on the things that very likely wont kill you (dyneema is used my many many many climbers in their anchors including guides and professionals, not too many deaths from that) vs other things that very likely will kill you ...


(This post was edited by bearbreeder on Dec 19, 2012, 3:55 PM)


markcarlson


Dec 19, 2012, 5:46 PM
Post #12 of 64 (7183 views)
Shortcut

Registered: Feb 13, 2009
Posts: 123

Re: [redlude97] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

redlude97 wrote:
It seems like in the first test and your diagram, the slack in the leg without a knot causes the force to be put on only 1 strand of the sling with the knot in it, is that correct?

I am surprised nobody pointed this out sooner. Is this something people do often?

I can not think of a time when I could have possibly weighted one side of a sling like that. That is, any time it looked possible (if a piece blew in a belay anchor,) I changed how the anchor was set up.


jt512


Dec 19, 2012, 9:06 PM
Post #13 of 64 (7157 views)
Shortcut

Registered: Apr 11, 2001
Posts: 21890

Re: [bearbreeder] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (1 rating)  
Can't Post

bearbreeder wrote:
the other interesting thing is that the guy at the end goes totally hands free on a gri gri with no backups when inspecting the sling ... which is likely more dangerous over time than the very rare occurrence of a true FF2 fall on dyneema ...

which i think goes to show the "fear" people have of dyneema ... vs the everyday hands free use of a gri gri or other such which is much more likely IMO of killing you ....

The fact that the guy went hands free on a(n already locked) grigri is irrelevant to the point of the video, which was the demonstration of a previously unknown (or little known) failure mode of a Dyneema sling. Secondly, there is no general "fear" (with or without quotes) of Dyneema slings, since they have mostly replaced nylon slings in practice. Third, if you ignore the results of the tests in this video, then you're an idiot.

Fourth, fuck Dyneema.

Jay


(This post was edited by jt512 on Dec 19, 2012, 9:07 PM)


bearbreeder


Dec 19, 2012, 11:27 PM
Post #14 of 64 (7139 views)
Shortcut

Registered: Feb 1, 2009
Posts: 1960

Re: [jt512] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

jt512 wrote:
The fact that the guy went hands free on a(n already locked) grigri is irrelevant to the point of the video, which was the demonstration of a previously unknown (or little known) failure mode of a Dyneema sling. Secondly, there is no general "fear" (with or without quotes) of Dyneema slings, since they have mostly replaced nylon slings in practice. Third, if you ignore the results of the tests in this video, then you're an idiot.

Fourth, fuck Dyneema.

Jay

blah blah blah blah Wink

like i said i find it quite odd when people go off about things while going against petzl's recommendation of a hands free device ...

no one is ignoring anything here mistah jay ... but there have been a few questions asked as to the test ...

theres plenty of "fear" going around about PASes, dyneema, ATC guides, etc ... on the intrawebs ... but as evidenced by the video, they dont take the basic safety precaution of tying off a device ...

if theres a test with a proper anchor (as others have pointed out) and a belay device in the system ... and dyneema consistently fails ... thats definately something to consider ...

until then ... ill focus on the stuff that will likely kill you

Tongue


patto


Dec 20, 2012, 12:17 AM
Post #15 of 64 (7123 views)
Shortcut

Registered: Nov 14, 2005
Posts: 1451

Re: [bearbreeder] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

bearbreeder wrote:
until then ... ill focus on the stuff that will likely kill you
Which is NOT sitting on a tightly cammed gri-gri!


bearbreeder


Dec 20, 2012, 12:27 AM
Post #16 of 64 (7116 views)
Shortcut

Registered: Feb 1, 2009
Posts: 1960

Re: [patto] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

patto wrote:
Which is NOT sitting on a tightly cammed gri-gri!

Tying off the GRIGRI to have your hands free


When you want to have your hands free to perform a manipulation, tie-off the GRIGRI. Make sure to correctly lock the tie-off. You may let go of the braking side of the rope only when the device is tied off.






if you really wanted to be "safe" according to petzl Wink

of course if the new RC stance is that the gri gri is now suddenly a hands free device ... now thats something ...

Tongue


jt512


Dec 20, 2012, 12:38 AM
Post #17 of 64 (7108 views)
Shortcut

Registered: Apr 11, 2001
Posts: 21890

Re: [bearbreeder] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

bearbreeder wrote:

theres plenty of "fear" going around about PASes, dyneema, ATC guides, etc ... on the intrawebs ... but as evidenced by the video, they dont take the basic safety precaution of tying off a device ...

What you think is "fear" is actually people making intelligent inquiries. And those inquiries are independent of whether they hang off a fully cammed grigri or not without a backup.

In reply to:
if theres a test with a proper anchor (as others have pointed out) and a belay device in the system ... and dyneema consistently fails ... thats definately something to consider ...

What's that called, the incautionary principle: "If anything can go right, it will"?

In reply to:
until then ... ill focus on the stuff that will likely kill you

Assuming everything in climbing is safe until absolutely proved otherwise is pretty stupid, although it is true that you will probably be ok.

Jay


bearbreeder


Dec 20, 2012, 12:52 AM
Post #18 of 64 (7101 views)
Shortcut

Registered: Feb 1, 2009
Posts: 1960

Re: [jt512] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (1 rating)  
Can't Post

jt512 wrote:

What you think is "fear" is actually people making intelligent inquiries. And those inquiries are independent of whether they hang off a fully cammed grigri or not without a backup.


What's that called, the incautionary principle: "If anything can go right, it will"?


Assuming everything in climbing is safe until absolutely proved otherwise is pretty stupid, although it is true that you will probably be ok.

Jay

no its simply focusing on things that are most likely to go wrong and kill you ... dont assume EVERYTHING is safe ... ANYTHING can kill you, but you cant worry about everything can ya now

the fear about "the deadly dyneema" occupies many intraweb threads ...

how about more basic stuff like wearing a helmet, which of course you ALWAYS do when leading dontcha mistah JAY Wink

what we have is an incomplete test IMO ... people have pointed out the funny anchor setup ... and we DO belay with a device or other such dont we ...

how many dyneema anchor FF2 failures have we had in real life ... i suspect there many be at least one or two since its a very common material ... and in fact i expect that there are at least a few nylon or cordellette failures in history as well ... but compare that to the much more common ways to die ... worry about the things that matter

tying off a proper anchor with dyneema, nylon, cord isnt whats going to kill you tmr (well it might if you are on such sketchy anchors that you cant clip the belay bolt or a piece, but are YOU doing such a climb mistah jay Tongue)

i once remember someone who yakked all about only climbing with partners who knew how to built zpulleys, using only lockers at anchors, unsafe PAS/dyneema ... what did he do? ... rapped off the ends of his rope ...


bottom line ... i want to see more info, a proper anchor setup and a belay device in the system ...

and if you are worried about being "safe" ... dont use a device that aint hands free according to the manufacturer ... well hands free Wink


(This post was edited by bearbreeder on Dec 20, 2012, 1:00 AM)


jt512


Dec 20, 2012, 1:05 AM
Post #19 of 64 (7091 views)
Shortcut

Registered: Apr 11, 2001
Posts: 21890

Re: [bearbreeder] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

bearbreeder wrote:
jt512 wrote:

What you think is "fear" is actually people making intelligent inquiries. And those inquiries are independent of whether they hang off a fully cammed grigri or not without a backup.


What's that called, the incautionary principle: "If anything can go right, it will"?


Assuming everything in climbing is safe until absolutely proved otherwise is pretty stupid, although it is true that you will probably be ok.

Jay

no its simply focusing on things that are most likely to go wrong and kill you ... dont assume EVERYTHING is safe ... ANYTHING can kill you, but you cant worry about everything can ya now

the fear about "the deadly dyneema" occupies many intraweb threads ...

how about more basic stuff like wearing a helmet, which of course you ALWAYS do when leading dontcha mistah JAY Wink

what we have is an incomplete test IMO ... people have pointed out the funny anchor setup ... and we DO belay with a device or other such dont we ...

how many dyneema anchor FF2 failures have we had in real life ... i suspect there many be at least one or two since its a very common material ... and in fact i expect that there are at least a few nylon or cordellette failures in history as well ... but compare that to the much more common ways to die ... worry about the things that matter

tying off a proper anchor with dyneema, nylon, cord isnt whats going to kill you tmr (well it might if you are on such sketchy anchors that you cant clip the belay bolt or a piece, but are YOU doing such a climb mistah jay Tongue)

i once remember someone who yakked all about only climbing with partners who knew how to built zpulleys, using only lockers at anchors, unsafe PAS/dyneema ... what did he do? ... rapped off the ends of his rope ...


bottom line ... i want to see more info, a proper anchor setup and a belay device in the system ...

and if you are worried about being "safe" ... dont use a device that aint hands free according to the manufacturer ... well hands free Wink

Do you ever write any sentences that aren't logical fallacies?

Jay


bearbreeder


Dec 20, 2012, 1:10 AM
Post #20 of 64 (7084 views)
Shortcut

Registered: Feb 1, 2009
Posts: 1960

Re: [jt512] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (1 rating)  
Can't Post

jt512 wrote:

Do you ever write any sentences that aren't logical fallacies?

Jay

yadda yadda yaddaa ... did ya say something mistah jay ;)

i suggest writing to all those manufacturers who make dyneema and tell them how "unsafe" you consider it to be for anchor usage ... as a recognized expert and knowing fully well that they did not test their materials in common usage setups ... theyll be shocked that you didnt come forward to them sooner ... this will insure positive change

or are you more interested in telling people they are "idiots" Wink


(This post was edited by bearbreeder on Dec 20, 2012, 1:11 AM)


healyje


Dec 20, 2012, 1:25 AM
Post #21 of 64 (7073 views)
Shortcut

Registered: Aug 22, 2004
Posts: 4199

Re: [jliungman] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

It's not new and it's not particularly alarming - people have been warned for some time that knotting dyneema is a bad idea. More of an issue with skinny dyneema slings is keeping and using them to long. They are designed as a ultralite, short-lifespan, alpine consumable and were never intended for long term use on trad racks or sport draws.


Syd


Dec 20, 2012, 2:26 AM
Post #22 of 64 (7060 views)
Shortcut

Registered: Oct 25, 2012
Posts: 300

Re: [healyje] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

healyje wrote:
More of an issue with skinny dyneema slings is keeping and using them to long. They are designed as a ultralite, short-lifespan, alpine consumable and were never intended for long term use on trad racks or sport draws.

It's not just dyneema that's short lived. I was surprised reading this recently:
" Testing by Todd Vogel at Blue Water Ropes showed consistent strength losses for most cords and tapes, after one or two years use the strength dropped to 60% even when there was no obvious wear. Id be replacing critical slings such as cordellettes every year or two."

Also:
http://www.efclimbers.net/resources/Knot-and-cord-strength.pdf


jt512


Dec 20, 2012, 3:11 AM
Post #23 of 64 (7049 views)
Shortcut

Registered: Apr 11, 2001
Posts: 21890

Re: [bearbreeder] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (1 rating)  
Can't Post

bearbreeder wrote:
jt512 wrote:

Do you ever write any sentences that aren't logical fallacies?

Jay

yadda yadda yaddaa ... did ya say something mistah jay ;)

i suggest writing to all those manufacturers who make dyneema and tell them how "unsafe" you consider it to be for anchor usage ... as a recognized expert and knowing fully well that they did not test their materials in common usage setups ... theyll be shocked that you didnt come forward to them sooner ... this will insure positive change

or are you more interested in telling people they are "idiots" Wink

I don't know how you escaped my killfile on this laptop, but back you go.

*plonk*


patto


Dec 20, 2012, 3:48 AM
Post #24 of 64 (7042 views)
Shortcut

Registered: Nov 14, 2005
Posts: 1451

Re: [bearbreeder] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

bearbreeder wrote:
patto wrote:
Which is NOT sitting on a tightly cammed gri-gri!
if you really wanted to be "safe" according to petzl Wink
This does not help your argument at all.

bearbreeder wrote:
of course if the new RC stance is that the gri gri is now suddenly a hands free device ... now thats something ...
You are confusing belaying hands free with having a loaded locked off gri-gri hands free. They are NOT the same!


A loaded grigri is 100% safe to go hands free provided the cam isn't forced open.


Forcing a cam open takes a fair bit of force that is very unlikely to occur when loaded. Like many such situations if you want to make it super safe tying off helps.


bearbreeder


Dec 20, 2012, 4:05 AM
Post #25 of 64 (7025 views)
Shortcut

Registered: Feb 1, 2009
Posts: 1960

Re: [patto] Video: Testing FF2 with dyneema [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

patto wrote:
bearbreeder wrote:
patto wrote:
Which is NOT sitting on a tightly cammed gri-gri!
if you really wanted to be "safe" according to petzl Wink
This does not help your argument at all.

bearbreeder wrote:
of course if the new RC stance is that the gri gri is now suddenly a hands free device ... now thats something ...
You are confusing belaying hands free with having a loaded locked off gri-gri hands free. They are NOT the same!


A loaded grigri is 100% safe to go hands free provided the cam isn't forced open.


Forcing a cam open takes a fair bit of force that is very unlikely to occur when loaded. Like many such situations if you want to make it super safe tying off helps.

ummmm ... that petzl diagram was very specific for descending (rappelling) on a gri gri ...

so you are saying that its 100% safe for one to go "hands free" on a gri gri if the cam is engaged ...

so for example is my climber is resting on the rope, the cam is fully engaged, i can let go of the brake hand ?????????

of course if you are swinging around theres absolutely no chance anything will happen at all will there now Wink

im gonna go ask petzl about it ... i suspect theyll know if its "100% safe"

Tongue


(This post was edited by bearbreeder on Dec 20, 2012, 4:10 AM)

First page Previous page 1 2 3 Next page Last page  View All

Forums : Climbing Information : The Lab

 


Search for (options)

Log In:

Username:
Password: Remember me:

Go Register
Go Lost Password?
$53.96 (10% off)
$17.95 (10% off)
$34.16 (10% off)
$10.76 (10% off)



Follow us on Twiter Become a Fan on Facebook