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TR trad gear test araps

mikllaw

14-Nov-2011
4:58:26 PM

As I couldn't face ever wearing boots again (though fabuluously sticky and precise, my solutions had become a problem - ha ha) I tested some gear on bouder below Castle Crag with Simey on Sunday.

I started with one of those skinny dyneema slings over a thin spike - I've always worried about them cutting. Instead, the anchors broke -Rock Empire nuts # 2 and #3 rated to 10 kN broke at 12.5 and 12.8 kN instead. Both broke at the nut, the holes are a bit close together.

sling with broken wire

Seemingly undamaged sling

Then we placed a 2RP in a good placement

The wire failed where it left the nut and touched the inside of the crack at 5 kN

The next placement ripped the rock at 2 kN

Then a good 1 RP, once agains the wire broke where it touched the rock (a worrying trend here) at 5.5kN


IdratherbeclimbingM9

14-Nov-2011
5:20:33 PM

Thanks for posting the feedback mikl.

I don't see any problem.

Some sites* I have checked, list the skinny dyneema slings as rated for 15kN (while others are 22kN!), and with the RPs, reckon #1 is good for 3kN, and #2 is good for 5kN.

Your one-off test-failures were <15kn for the sling (when the nuts failed), 5kN and 5.5kN respectively for the RPs.
(*I would link them, but Chocky keeps giving me 'suspicious content' message and won't let me!).

>once agains the wire broke where it touched the rock (a worrying trend here)

Pretty hard to avoid, but still within spec.
With many 'failed' RPs that I have seen (rubbish left on climbs mostly), the failure mode was breakage of the wire within the clip-loop, and no particular rock edges/projections in sight to blame as culprits.
A short while back, our aid group witnessed a similar RP failure while climbing at Buffalo, but we put that one down to the notch in the krab catching the wire during the fall happening onto it at the time.

I would be interested in knowing what 'doubled up' small RPs fail at.

torque

14-Nov-2011
5:27:55 PM

I always love reading these real world tests.

I'd be keen to see the results of dyneema/spectra sling (like the one pictured) tested in a Larks foot configuration. Some anecdotal evidence suggests that these materials may not perform to spec when used like this. By 'anecdotal evidence' I mean I read a post on an Internet forum about this, so take it as you will.

Happy to pitch in for the cost of the sling, as I'm rather curious as to the result.


Macciza

14-Nov-2011
7:04:53 PM

Hi Mikl
> once agains the wire broke where it touched the rock (a worrying trend here) at 5.5kN . .

Wouldn't this be the expected failure mode? Under massive tension the damage to even one strand of wire would compromise the whole shebang and the strands are very thin on the small RPs.
And does he use stainless? Would it be different to 'normal wires' wire? just a thought . . .
Cheers

widewetandslippery

14-Nov-2011
7:14:33 PM

Is simon fit or is the cafe going shit or is he on the gear?


shortman

14-Nov-2011
7:27:01 PM

On 14/11/2011 widewetandslippery wrote:
>Is simon fit or is the cafe going shit or is he on the gear?

Gold! Call of the day.

bl@ke

14-Nov-2011
10:42:36 PM

Gotta love when RP's snap with bodyweight.

mikllaw

14-Nov-2011
10:57:34 PM

On 14/11/2011 IdratherbeclimbingM9 wrote:
>I would be interested in knowing what 'doubled up' small RPs fail at.

'doubled up'?
Is this two cRPs clipped into one krab? Unless they are perfectly equalised, one would break , then the next.
If they are equalised, twice the lowest failure strength.


Ben_E

14-Nov-2011
10:59:46 PM

On 14/11/2011 bl@ke wrote:
>Gotta love when RP's snap with bodyweight.

Really? I mean, the rock blew at 2kN (a touch over 200kg)in one of the above tests and the others went at ~5kN. Have you put on weight since I last saw you!?!? ;-)

Hopefully you're talking about some other incident(s)!

One Day Hero

14-Nov-2011
11:08:37 PM

On 14/11/2011 mikllaw wrote:
>Then a good 1 RP, once agains the wire broke where it touched the rock
>(a worrying trend here) at 5.5kN

#1RP holds 550kg!?!?!

That's fuching awesome, those things have cables thinner than gear shift cable on a pushie. How sweet are Roland's old school eastern euro metalworking skills!


Ben_E

14-Nov-2011
11:09:15 PM

As an aside, good to see the dental floss dyneema sling hold its own, given I usually climb with a few of them racked with biners as slowdraws.

One Day Hero

14-Nov-2011
11:11:29 PM

On a less 'fanboy' note, placements which load the rock so that a small surface area can fail in tension or shear seem bad, bad, bad. Rock is really strong in compression but you wouldn't want to make bolts out of it.


IdratherbeclimbingM9

14-Nov-2011
11:17:33 PM

On 14/11/2011 mikllaw wrote:
>On 14/11/2011 IdratherbeclimbingM9 wrote:
>>I would be interested in knowing what 'doubled up' small RPs fail at.
>
>'doubled up'?
>Is this two cRPs clipped into one krab? Unless they are perfectly equalised,
>one would break , then the next.
>If they are equalised, twice the lowest failure strength.

Thanks for the feedback.
When I typed the Q, what I had in mind was one backing up another and equalised to take the potential load.
Now you point it out, it seems simple maths, but I guess I was vainly hoping the total might be more than the sum of its parts(!), which says volumes for the added benefits of having dynamic loading / screamers, etc.

Another point worthy of note for your tests, is that the placements were done well, and in good rock, both factors that if compromised, would lead to a lower fail figure.

bl@ke

14-Nov-2011
11:18:56 PM

On 14/11/2011 Ben_E wrote:
>On 14/11/2011 bl@ke wrote:
>>Gotta love when RP's snap with bodyweight.
>
>Really? I mean, the rock blew at 2kN (a touch over 200kg)in one of the
>above tests and the others went at ~5kN. Have you put on weight since I
>last saw you!?!? ;-)
>
>Hopefully you're talking about some other incident(s)!

The last aid weekend. Someone was chilling on one with some etts and the wire snapped. Ha!

simey

14-Nov-2011
11:31:10 PM

Mikl neglected to mention that we also did some testing on the 2011 model of Mikl compared to the 1978 version. The testing took place on the recently retro-bolted, but still sparsely protected Jenny Wren via Direct Start (21). The Direct Start was first climbed by Mikl in 1978 with zilcho protection. The 2011 Mikl recorded a surprisingly poor failure rating... complete failure at first bolt followed by a lower to the belay. Simey then took over and gave a fine demonstration of getting scared on lead, despite having top-roped and retro-bolted the climb only a year ago.

After these disappointing results, we decided to do some further testing back in the campground which involved drinking beer and chatting to attractive European climbers. I can safely say that neither Mikl or I showed any deterioration whatsoever in our ability to talk ourselves up in front of the opposite sex.

pecheur

15-Nov-2011
7:53:13 AM

On 14/11/2011 Macciza wrote:
>Hi Mikl
>> once agains the wire broke where it touched the rock (a worrying trend
>here) at 5.5kN . .
>
>Wouldn't this be the expected failure mode? Under massive tension the
>damage to even one strand of wire would compromise the whole shebang and
>the strands are very thin on the small RPs.

I agree (sort of), I would have thought the standard failure mode would have been the rubbing of the wire against the rock causing a "crack" in a strand of wire, which under tension leads to fast propagation in the strand and then complete failure of the entire wire.

kieranl

15-Nov-2011
9:33:27 AM

On 14/11/2011 simey wrote:
>Mikl neglected to mention that we also did some testing on the 2011 model
>of Mikl compared to the 1978 version. The testing took place on the recently
>retro-bolted, but still sparsely protected Jenny Wren via Direct Start
>(21). The Direct Start was first climbed by Mikl in 1978 with zilcho protection.
>The 2011 Mikl recorded a surprisingly poor failure rating... complete failure
>at first bolt followed by a lower to the belay. Simey then took over and
>gave a fine demonstration of getting scared on lead, despite having top-roped
>and retro-bolted the climb only a year ago.
>
>After these disappointing results, we decided to do some further testing
>back in the campground which involved drinking beer and chatting to attractive
>European climbers. I can safely say that neither Mikl or I showed any deterioration
>whatsoever in our ability to talk ourselves up in front of the opposite
>sex.
>
Research continues...

kieranl

27-Dec-2011
8:23:08 PM

Hi Mikl, Simey, were these tests done on the Good Morning Arapiles boulder? I was surprised to find a couple of insitu trashed RPs there this evening.
Whatever the origin I'm pretty disappointed that whoever placed them didn't clean them up.
I'll go back with a light hammer and knifeblade tomorrow evening and see if I can remove them without excessive damage to the rock. Alternatively I'll chop the cables as flush as possible.

mikllaw

27-Dec-2011
8:47:17 PM

Absolutely, unfortunately I didn't have a hammer or piton with me but they should tap out easily

simey

27-Dec-2011
10:53:49 PM

I told Mikl to leave them in. I thought they were an amusing little addition to the boulder and would generate some interest/curiosity. They are not exactly permanent fixtures and they will be a cinch to get out.

There are 23 messages in this topic.