UKC

So, we all know about loading carabiners over an edge and how it can be severely weakened/snap when loaded. For me the problem mainly arises with nuts on wire, which is easily solved by basket hitching a sling to extend the piece.

Last weekend I found I needed to do the same with a tricam however, nothing else would fit and in the back of my mind was 'never nylon on nylon!'. I slung it and moved on, but thought I'd check what people thought, is it okay to use nylon on nylon here as there isn't much movement between the two slings,, or is there a better way around this that I didn't think of?

In reply to alooker:

Better than nout?

Inspiration or idiocy incoming - Is there a loop near the metal end of the tri cam (how it's attached?) that you could have clipped with a quickdraw?

In reply to alooker:
A belay loop (nylon) applies forces to the waist belt (nylon) & leg loops (nylon). As long as nylon is not moving or sawing through nylon it should be fine.

In reply to alooker: Excerpt from Black Diamond instructions:

"Warning: (...) Always use a carabiner to clip to the cable wire. Never thread webbing directly through a Stopper or Hexentric cable.(...)"

In reply to PMG:

Did you actually read the OP? He's talking about nylon/nylon not nylon/wire.

If it's all you've got then nylon/nylon will have to do. I wouldn't worry yourself too much about it. It you avoid placing anything there because you're worried about the nylon/nylon link then you'll miss out on a piece of protection that will more then likely work.

In reply to alooker: Perfectly acceptable to larks foot nylon slings of the same thickness together as long as they are static. I.E aren't rubbing against one another!

In reply to elsewhere: very true.

Thanks everyone, just wondered if anyone had any better ideas. I never tested it so couldn't tell!

In reply to PMG: none of this is gonna get full strength from everything of course, I'd rather improvise than snap a carabiner though. http://dmmclimbing.com/knowledge/improvisation-larks-foot-or-basket-hitch-v...

In reply to alooker: Thanks for the link.

In reply to climber_medic:

I'd be suprised if a larks foot was as strong as a basket hitch.

In reply to alooker:


Sounds fine to me, I'd not give that a second thought.
jk

In reply to alooker:

http://www.viamontgear.com/gear/tricams/tricams.htm

In reply to alooker:

I've wondered the same - how would a maillon cope with being loaded over an edge?

In reply to PMG:

Although this is what is tested in the video from DMM - outside recommended use, but the safest option in their test (albeit they didn't test over an edge)

Interesting they showed a basket hitch is stronger than lark's foot ... and as he points out much easier and quicker one handed.

In reply to alooker:

When you tie a knot in a nylon sling you effectively have a nylon on nylon situation, as long as there no movement to generate heat it'll be ok.

In reply to sparra: In the case of basket hitch load is distributed between four strands. There is also no knot. No surprise it is stronger.

Rated at 7 kN lark's foot on wire is too weak to be trusted. There is simply no margin left.

Sharp edge can simply cut the webbing but rounded one may be beneficial reducing force transferred to the crucial wire-webbing joint (due to friction between the webbing and the rock).

In reply to mlmatt:

The OP at the very top of the thread you mean? The one that says this:
"For me the problem mainly arises with nuts on wire, which is easily solved by basket hitching a sling to extend the piece."

In reply to nameless_rob:


Why would you bother?

jk

In reply to alooker:

The dangers of being too dogmatic ! Personally I'd far rather loop a sling through a sling than have a caribiner bent over an edge. I've seen how the gates lever open even under body weight and I've also seen one broken by a poor unfortunate during a fall.

If there was no alternative wire position which could avoid it, I'd also be a lot happier with a sling looped through (not larks footed) a wire rather than load a caribiner over an edge.

Sure, theoretical strength may be compromised but its actually very rare (for me) to get into a situation where a) a crab over an edge is unavoidable and b) its my only crucial runner.

In reply to GrahamD: Agreed with it being relatively rare. General consensus seems to be that I didn't do anything wrong, then! So glad I'm not GONNA DIEEE! ......

I nylon on nylon all day long, metal on metal too.

Bit of homomaterialism hasn't ever been much of a concern of mine.

In reply to alooker: as referred to by others above the problems with nylon on nylon occur either:
A) if movement of any sort could be present (especially when under load),
B) if there is a difference in thickness leading to a 'cheesewire' effect.

The DMM website has some excellent videos/tests in their 'knowledge' section.

As pointed out by PMG/Black Diamond I would certainly not recommend threading a sling directly through a wire, instead I would use a second wire. Again I'd recommend a look at the DMM site (no, I don't work for them).


Tim

In reply to TimH: oops, didn't see that the vid had already been linked

In reply to TimH:

From DMM's info, I've come to a different conclusion...With my newish slings basket hitching to my DMM Wallnuts, it's fine. The nut will exceed its rated strength before the sling breaks.

Anyone have test results for joining wires? Wire breaks too....The question being is it stronger or weaker to girth hitch two wires than it is to basket hitch a sling to a wire.

In reply to needvert:

http://dmmclimbing.com/wp-content/uploads/2011/12/larksfoot-basket-table.jp...

Joining a Wallnut 1 to a Wallnut 1 gives a failure load of 7.6 kN

8mm Dyneema basket hitched to Wallnut 1 gives a failure at 9.7kN
(9.6 kN for 11mm Dyneema)

In reply to cuppatea:

Ahh thanks for that

In reply to needvert:

Not at all. The numbers surprised me! I'm sure I wasn't alone in thinking that joining wires together would be much stronger than joining a wire to a sling...

In reply to alooker:


We're all going to die, I'm afraid

In reply to cuppatea & needvert: thanks, I'd missed that bit. Surprised that the difference in thickness between the wire & the sling doesn't cause a problem.

Cheers for the link,


Tim