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Drop tests on autolocking belay devices ?
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verticon


Feb 7, 2010, 12:38 PM
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Drop tests on autolocking belay devices ?
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Do you know of any drop tests performed on autolocking belay devices (Reverso 3, BD ATC Guide, etc.) ?
According UIAA-129 http://www.theuiaa.org/...g_device_2009(1).pdf the static strength should be ~8 kN, but there is also a dynamic performance test for locking assisted braking devices only (page 8) which might apply to the Reverso type in autolocking setup.
I just wonder if the rather thin attachment point of the Reverso 3 could take such a drop.


csproul


Feb 7, 2010, 1:18 PM
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Re: [verticon] Drop tests on autolocking belay devices ? [In reply to]
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Since these devices are only meant to be used in autoblock-mode when belaying a second and should not be subject to such a dynamic force, what would be the relevance of such a test?


rschap


Feb 7, 2010, 5:37 PM
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Re: [csproul] Drop tests on autolocking belay devices ? [In reply to]
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Well, I agree with you but I did watch a guy take a 30ft fall on second in Ouray once. While it shouldn’t happen it does sometimes.


vegastradguy


Feb 7, 2010, 6:13 PM
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Re: [verticon] Drop tests on autolocking belay devices ? [In reply to]
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verticon wrote:
Do you know of any drop tests performed on autolocking belay devices (Reverso 3, BD ATC Guide, etc.) ?
According UIAA-129 http://www.theuiaa.org/...g_device_2009(1).pdf the static strength should be ~8 kN, but there is also a dynamic performance test for locking assisted braking devices only (page 8) which might apply to the Reverso type in autolocking setup.
I just wonder if the rather thin attachment point of the Reverso 3 could take such a drop.

i would suspect that autolocking tube devices dont fall into the locking assisted devices category and are thus not subject to the dynamic loading test.


USnavy


Feb 7, 2010, 11:31 PM
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Re: [verticon] Drop tests on autolocking belay devices ? [In reply to]
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verticon wrote:
Do you know of any drop tests performed on autolocking belay devices (Reverso 3, BD ATC Guide, etc.) ?
According UIAA-129 http://www.theuiaa.org/...g_device_2009(1).pdf the static strength should be ~8 kN, but there is also a dynamic performance test for locking assisted braking devices only (page 8) which might apply to the Reverso type in autolocking setup.
I just wonder if the rather thin attachment point of the Reverso 3 could take such a drop.

Auto-blocking, not locking. Auto-locking: GriGri, Cinch, ect.


(This post was edited by USnavy on Feb 7, 2010, 11:32 PM)


verticon


Feb 8, 2010, 12:01 AM
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Re: [vegastradguy] Drop tests on autolocking belay devices ? [In reply to]
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vegastradguy wrote:

i would suspect that autolocking tube devices dont fall into the locking assisted devices category and are thus not subject to the dynamic loading test.
I agree, the Reverso isn't fitting the exact definition of a "locking assisted device", but if you replace the Grigri in the picture from pg.8 in the UIAA-129 with a reverso in autoblock mode you get basically the same setup, working the same way. And I can imagine a couple of situations when a second might fall with a high enough fall factor (mabe even FF1 ?!)on such a setup. Do you find the attachement point of the Reverso to be confidence inspiring for such a case ?


JimTitt


Feb 8, 2010, 1:25 AM
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This isnīt any sort of official test and for the strength of the attatchment loop you can easily contact Petzl (or DMM who make them) but from the testing Iīve done it holds at least 7.15kN. With any normal climbing rope you cannot get higher values on the device as the rope squeezes down and crosses through the slots, first jamming the rope and then at higher loads it crosses out through the slot on the braking karabiner side and effectively is released.
For thinner/softer ropes the release values are quite low which is why Petzl specify minimum diameters for use in autlock mode (8,5mm in single strand mode) as opposed to 7,5mm with two strands.
(I tested a couple of devices in this mode for a guy who was contemplating using them as a lead roped-solo setup-I was not converted!)


Jo_Rock


Feb 8, 2010, 3:40 AM
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Re: [JimTitt] Drop tests on autolocking belay devices ? [In reply to]
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I've actually used mine this way, but I was in no danger of falling till I had about 60' of rope out, so low fall factor, and my backup knot would have kept me from decking. Needless to say, if you have that compiled somewhere on RC and know where I'd be interested.


Jo_Rock


Feb 8, 2010, 3:47 AM
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BTW I realize this is not recommended and I am NOT recommending that anyone else do this either. I was using it in a situation where I was almost comfortable free soloing and realized that there was a distinct possibility that it would fail and drop me to my backup knot and was ok with the risk of that possibility.


JimTitt


Feb 8, 2010, 5:15 AM
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With any sort of rope a sane man would be roped soloing on (though using a guide plate system to roped solo isnīt nescessarily my idea of the actions of a sane man, I use a modded Grigri) you are probably not going to die as there is quite a lot of residual friction with say a 9.8mm rope. The bigger problem is that after the first crossing-over stage the rope is jammed solidly in the plate and you have to release the load on the rope (Prusik or so) to be able to wrench the carabiner free, if you are prepared then no problem but if not.....


Jo_Rock


Feb 8, 2010, 10:18 AM
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Aaaaaahhh... good to know. I was not prepared for that, but I am sure I would have figured something out. I too have moved to a Gri Gri system, but knowing the failure mode and being prepared for it leaves a possibility for use with a "leader must not fall" mentality. Do you remember off hand about how many tests you did and if you did an ATC Guide how that fared? (It looks stronger.) Was this before the Reverso 3.

Thanks


JimTitt


Feb 8, 2010, 10:58 AM
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Oops! I didnīt make that very clear, the tests were done on a Reversoģ and an ATC GUIDE, not on the older Reverso itself. Looking at the forces Iīd think that the folded sheet construction is going to distort a bit and let the rope through easier.
The ATC guide was better all the way through but Iīve mislaid the paper with the later results, Iīm pull testing some other stuff on Wednesday so Iīll do the tests again and post them here.


Jo_Rock


Feb 8, 2010, 11:32 AM
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Thanks!!!


verticon


Feb 9, 2010, 4:37 AM
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Thank you, really useful information, I can't wait to see the test results


JimTitt


Feb 10, 2010, 11:41 AM
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Another day, another broken rope!

When you overload guide plates they do funny things.
The first is that the trapped rope escapes sideways from under the tensioned rope and gets trapped between the tensioned rope and the side of the slot.This is very difficult to free off and you have to dismantle everything and twist the locking krab brutally to release the rope. Take your Prusiks.
Apply yet more load and the trapped rope where it crosses the tensioned rope goes down through the slot with a bang. At this point the holding power drops off considerably but not catastrophically, though pretty near! This is easy to release, just unclip the krab when unweighted. Still need to take your Prusiks!

ATC Guide. 8.2mm Edelrid, new,treated. First fail mode 2.05kN. Max fail load 4.06kN. Residual load 1.2kN
ATC Guide. 9mm Edelrid, used, good condition, non treated. First fail mode 2.96kN. Max fail load 5.58kN. Residual load 1.6kN
ATC Guide.10mm Tendon. Used, good condition, treated. First failure mode 5.86kN. NO second failure mode. Sheath ripped 6,62kN.

Reversoģ. 8.2mm Edelrid, new,treated. First fail mode 1.6kN. Max fail load 2.38kN. Residual load 0.7kN
Reversoģ. 9mm Edelrid, used, good condition, non treated. First fail mode 2.25kN. Max fail load 3.60kN. Residual load 0.9kN
Reverso ģ. 10mm Tendon. Used, good condition. treated. First fail mode 4.66kN. No second fail mode. Sheath stripped at 5,56kN.

All with Petzl Attache 12mm round profile karabiner.

Both plates showed signs of damage on the underside where the carabiner is forced onto the side webs and needed filing to remove the burrs before further use.


Jo_Rock


Feb 10, 2010, 1:03 PM
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Great info, not so great a solo belay device. Thanks a bunch. Not the failures I initially would have expected so really good info.

J


verticon


Feb 10, 2010, 11:53 PM
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That's funny... I expected the Reverso to perform better than the ATC in autoblock mode, because it has narrower slots (by ~2 mm), so the ropes have less space to cross each other.
How do you explain the "counterintuitive" results?


JimTitt


Feb 11, 2010, 1:31 AM
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Itīs because of the orientation under load (the relative position between the fixing point, the V-slots and the loose karabiner), on the Reversoģ the trapped rope doesntīt lie as deep in the V-grooves as on the ATC and so it escapes out to the side more easily. This however makes the Reverso the easier to release when your hopeless second is hanging on it so perhaps it is a reasonable compromise.
If you want real holding power the older style Bonatti (and other) plates had very gently tapering slots and these donīt display the crossing-over effect but just force the braking strand even further down the slot, of course they are a pain to release in some cases and were very sticky to use.
The drive for smaller and lighter devices mean somewhere a compromise has to be made, and then preferably sold as an advantage to the customer!


sherpa79


Feb 11, 2010, 5:23 AM
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Thanks for the info Jim, I was just wondering how a couple of lower 8mils would perform in my ATC Guide. I put some 8mm accesory cord in there and just bounced hard on them. Real numbers are cool!


verticon


Feb 11, 2010, 5:55 AM
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Thanks for the info. I use Reverso 3 with Beal ropes of similar diameter : Ice Lines (8.1 mm), Cobra (8.7 mm) and Booster (9.7 mm) and it's good to know what it might happen if the second falls with some slack in the system.


(This post was edited by verticon on Feb 11, 2010, 5:58 AM)


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