Author Topic: Tested to destruction: new (2013) Petzl Croll  (Read 15902 times)

Offline Cap'n Chris

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Tested to destruction: new (2013) Petzl Croll
« on: April 19, 2013, 08:48:46 pm »
Just got a message through from some Spanish caving chums about the new Croll. Photo shows various failures, here:



Awaiting further details.....
« Last Edit: April 20, 2013, 06:53:12 am by Cap'n Chris »

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Tested to destruction: new (2013) Petzl Croll
« on: April 19, 2013, 08:48:46 pm »
Warmbac

Online Pete K

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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #1 on: April 19, 2013, 08:55:12 pm »
Looks like they have bent out of shape under load. Do you know if this is the result of testing or in use failures?
« Last Edit: April 20, 2013, 06:44:22 am by Cap'n Chris »

Offline Cap'n Chris

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Tested to destruction: new (2013) Petzl Croll
« Reply #2 on: April 19, 2013, 08:57:40 pm »
The Spaniards forwarded a document from some Italian cavers; I don't know enough Italian to work out what's going on but from the photo below clearly it's a replicated failure in the main body of the device and is probably a result of shock/load testing - I'm guessing the failures are at quite low loads, though, since the ropes do not show evidence of major damage to the sheaths which you would expect if doing some serious drops.

UPDATE: huge loading was required to create this failure - subsequent information shows that this "problem" is unlikely to occur in any normal use scenario! Which is good to know.



« Last Edit: April 20, 2013, 06:54:13 am by Cap'n Chris »

Offline droid

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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #3 on: April 19, 2013, 08:59:41 pm »
Looks more like breakage than bending....
« Last Edit: April 20, 2013, 06:45:42 am by Cap'n Chris »
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Offline Cap'n Chris

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« Last Edit: April 20, 2013, 06:45:58 am by Cap'n Chris »

Offline Cap'n Chris

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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #5 on: April 19, 2013, 09:02:35 pm »
Progressive loading to destruction, rather than shock load. Apparently.
« Last Edit: April 20, 2013, 06:46:13 am by Cap'n Chris »

Online Pete K

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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #6 on: April 19, 2013, 09:05:07 pm »
Looks more like breakage than bending....
Agreed, the reverse shot is even more worrying than the front one.
Best get that emailed over to Petzl / Lyon Chris if not done already. I'm sure they'll have something to say.

Edit -
Any figures for failure load?
« Last Edit: April 20, 2013, 06:46:29 am by Cap'n Chris »

Online Pete K

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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #7 on: April 19, 2013, 09:13:58 pm »
Google Translate:

During the experimental research carried out in the laboratories of the GLM Costacciaro, with slow tensile tests (vd = 0.005 s-1) and fall (vd = 4,429 s-1) were tested several blockers ventral cords applied to new and used.
Everyone has given excellent results reported with the exception of the Petzl Croll put on sale starting from January 2013 (photo no. 1) that it broke even with loads of just 500 kgp, making reverse the ratchet and escape the rope, without tearing the sheath and begin the process of energy absorption related to the sheath slippage on strands interiors (photo n. 2-3).

The specimens examined (bought in a sporting goods store with regular invoice, in original packaging) are identifiable by their acronyms are described in the ratchet.

The Petzl Croll 2013 differs from the previous model:
1.
a plate with reduced thickness of about 1 mm,
2.
a protective steel inside the throat of slip of the rope,
3.
the absence of a system of tilt of the ratchet.
The most marked effects occurred at slow traction (vd = 0,005 s-1) with forces between 400 and 600 kgp kgp, with the breaking of the back of the tool, the opening of the throat, the overturning of the ratchet and spill rope (photo n. 4-5).

In some cases the throat did not open completely, the ratchet albeit slightly not rolled over,
the shield is broken, but immediately after the ratchet strangled to the point where the strands to break
all in no time. Has not triggered any phenomenon of energy dissipation with
sheath slippage on the soul of the rope.
In tests in fall (vd = 4,429 s-1) the throat does not
is open and the ratchet is not overturned, but
after breaking of the sock all the strands were
sheared the rapid succession. In these cases the
blocker is unusable as the result
throat is open by a few millimeters and the rope
was able to escape with a minimum tensile
transverse.
The deformation of the throat also occurs with
small stresses (300 kgp - 400 kgp) to
result of which is a measure opening
Additional few tenths of a millimeter.
Added to other similar solicitations
the opening of the throat continues to increase.
The results listed above were obtained on
following strings:
1. Beal Antipodes New 10 mm (static)
2. Beal Antipodes 10 mm Used (static),
3. Edelrid SS 10 mm Used (static)
4. Last Courant New 10 mm (static)
with strands glued inside the
stocking,
5. Last Courant New 11 mm (static)
with strands glued inside the
stocking.
The worst results have occurred with the strings Last Courant (braid bonded to the strands) and, above all,
with the strings used (most common state in the progression in the cave).
For all this I think that the Petzl Croll 2013 as a blocker that should be used with extreme caution, with frequent observations of his condition and replace if it can suffer a solicitation of more than 400 kgp. It should also be very careful on the rise in splits with pitches very moved, however, whenever the length of rope downstream of the cross-blocker exerts traction.

In contrast, a Petzl Croll product before (recognition code 10266FU8865, then produced in the 266 th day of 2010), with rollover of the ratchet (photo no. 6) resulted in an exceptionally durable and reliable tool that has endured numerous tests, with stress to the limit, without showing deformation and structural failure.
E 'was also tested at a slow loading Petzl Croll without tipping the ratchet product in the eighties of the past century: with a maximum stress of 600 kgp rolled over the ratchet and release the rope to the enlargement of the throat (photo . 7). Behavior almost similar to that of Croll, 2013, with the only difference that the back is not fractured.
I believe that the main causes that determine the behavior of the model 2013 Petzl Croll are to be found in the reduced thickness of the plate and in the absence of the system "rollover" of the ratchet.
Costacciaro April 18, 2013
« Last Edit: April 20, 2013, 06:46:45 am by Cap'n Chris »

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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #8 on: April 19, 2013, 09:33:10 pm »
Chris, if possible can you find out from your source via their source if the 2013 Basic was tested please? The text indicates other jammers were looked at but all showed higher strengths with only the Croll warranting a report.
« Last Edit: April 20, 2013, 06:47:04 am by Cap'n Chris »

Offline Cap'n Chris

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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #9 on: April 19, 2013, 10:51:28 pm »
It would appear that these failures are a result of testing to destruction. The loads required to create this fracture failure are immense and way beyond any which can be created during normal caving use.

It's interesting to see nonetheless.
« Last Edit: April 20, 2013, 06:54:57 am by Cap'n Chris »

Offline Loki

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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #10 on: April 19, 2013, 11:12:38 pm »
the EN standard that jammers are tested to requires a test load of 4kN (roughly 400kg) so the fact that they fail at loads of 500kg is irrelevant as its outside the certification requirements.  if a person were to put loads over 400kg on the device they would have to be doing something particularly stupid.

i have done tests dropping 100kg steel masses onto cowstails attached to jammers on ropes and the loads involved would not cause these failures.   

its also a commonly known fact that jammers strip rope sheathes at loads over 400kg if they have sharp teeth. 

remember that ascenders are for humans to ascend ropes with, they are not for belaying/self lining with, or hauling cars out of ditches in a pulley system.

Take this report with a pinch of salt.

PS. i dont work for Petzl or a distributor but i am in the industry.
« Last Edit: April 20, 2013, 06:47:52 am by Cap'n Chris »
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Offline droid

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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #11 on: April 20, 2013, 04:40:15 am »
Reading the translation above, it seems a non-recoverable deformation occurred at 3kN.

It also seems to state that no damage to the sheath occurres at 4 kN.

The caveat being that I'm reading this after a night shift so I might be misinterpreting it....
« Last Edit: April 20, 2013, 06:48:10 am by Cap'n Chris »
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Offline Cap'n Chris

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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #12 on: April 20, 2013, 06:49:54 am »
Moderator Comment Changed the title to a more accurate (less alarmist) one reflecting the nature of the testing

Offline Cap'n Chris

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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #13 on: April 20, 2013, 05:45:55 pm »
Copied response from today from Petzl to my chum who brought the topic to attention yesterday, here:


"Hello Octavio,

Yes we are aware of this [italian] publication and this is our answer.

Following the recent publication of 2013 Croll tests on http://www.sns-cai.it/item/test-sul-crol-petzl-di-recente-produzione Petzl wishes to remind the following facts:

* - The new 2013 Croll complies with the requirements of the EN567 standard on the authorized types of ropes with the product (8-11mm), 5 consecutive static pulls of 4kN. During these tests the clamp was never pulled out.

* - We have tested the new 2013 Croll with a large panel of ropes in slow traction. The measures at which the sheath of the rope was torn were very good : 5kN for the 8mm, 6-7 kN on the other diameters.

* - During the development of the product and on the serie production, we have conducted many dynamic tests (shock with rigid mass near an anchor point or extreme destructive test with a guided mass on worn out ropes of high diameter, in these tests the clamp was never pulled out, the sheath of the rope was torn.

* - In normal use the Croll should never be solicited at these values, there are no safety problems to use this product according to the technical notice : http://www.petzl.com/files/all/technical-notice/Sport/B16-CROLL.pdf

* - Petzl will of course contact as soon as possible the authors of these tests for exchange of informations.

Thank you very much for your Message.

Laurent
Petzl Community Manager"





Spec sheet:


Online Pete K

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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #14 on: April 20, 2013, 06:00:47 pm »
Good to see Petzl on the ball as usual.

Out of interest, does anyone have a copy of the full text of EN 567: 1997 for reference. I can only find paid copies online.

Online nickwilliams

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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #15 on: April 20, 2013, 08:09:08 pm »
Pete,

If you live in Derbyshire, you can access it via the Derby County Library Service:

http://www.derbyshire.gov.uk/leisure/libraries/online_information/british_standards/default.asp

You need to be a library member, but membership is free.

Nick.

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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #16 on: April 20, 2013, 08:13:35 pm »
Thanks Nick :thumbsup:

Offline wookey

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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #17 on: May 01, 2013, 03:08:39 am »
Quote
remember that ascenders are for humans to ascend ropes with, they are not for belaying/self lining with, or hauling cars out of ditches in a pulley system.

Hmm, not sure about that last one. Happens regularly :-) How else are we supposed to get the car out of the ditch/hedge at 2am whilst escaping (extraordinarily inefficiently) from the campsite without paying?


Offline brusc

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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #19 on: June 03, 2013, 12:54:09 pm »
Petzl sound a bit pissed off.

Online Speleotron

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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #20 on: June 03, 2013, 01:11:20 pm »
I would be as well, who would ever load a jammer to 4 kn?
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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #21 on: June 03, 2013, 01:36:49 pm »
Interesting that the removal of the cam stop results in weight-loss - I would have thought the original cam-stop design wouldn't have a significant 'weight' issue as such, as it's just part of the frame bent through to the inside? Whether leaving the frame 'solid' or pushing a bit through, it's still the same amount of metal? I'm guessing it's more that the smaller frame just doesn't leave enough room to create the cam-stop safely.

Offline ianball11

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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #22 on: June 03, 2013, 01:51:58 pm »
I like seeing Petzl defending their kit.

Offline droid

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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #23 on: June 03, 2013, 01:59:45 pm »
They'd be rather unwise NOT to defend their kit.

Interesting though that their first comment was that the information would damage the company....rather than damage the product user.... ::)
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Offline ianball11

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Re: Tested to destruction: new (2013) Petzl Croll
« Reply #24 on: June 03, 2013, 02:20:17 pm »
Like speleotron said, 4kN on a jammer is a high number.

They could have just stated it meets the necessary legislation and left it at that.  The defensive position with self arranged and independent testing to confront the claims is much more calming to me.

 

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