/ Threading slings directly to wires

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kingjam - on 23 Jul 2013
Hi


I was told this weekend that threading a sling directly into a wire ( instead of use a crab ) was a bad thing ( i was trying to extend and only had a sling and a crab) . Appreciate that wires are abrasive but wouldn't have through the friction generated from a fall would be enough too sheer the tape especially if the tape is tied tightly with a larks foot .

Only other issue I could see is potentially dislodging they nut as the rope moves up .

Any views ?
johncoxmysteriously - on 23 Jul 2013
In reply to kingjam:

I did that once all the way up the second half of Milky Way on Lundy. A very experienced climber assured me that if I'd fallen off I would have torn straight through every sling. Didn't sound very likely to me, but I'll be interested to see what's said.

jcm
Dervey - on 23 Jul 2013
RomTheBear - on 23 Jul 2013
In reply to kingjam: As far as I know it is acceptable pratice if abseiling off it, but I wouldn't trust it to hold a hard lead fall.
3 Names - on 23 Jul 2013
In reply to kingjam:

Isnt this the reason that camalots dont have an extendable sling?
GridNorth - on 23 Jul 2013
In reply to kingjam: It was a common way of using wires back in the 60's when they first came out but back then even a few karabiners weighed a lot and it was not practical to carry too many. Added to that we didn't know any better. I never heard of one being cut by the wire. I wouldn't do it now unless of course I had no alternative. I always work on the principle that something is, 9 times out of 10, better than nothing when it comes to protection.
lithos on 23 Jul 2013
In reply to kingjam:

if you thread it (basket hitch not larks foot) they are pretty strong.
see the dmm video/page : 9..12kn

I use it if there is a danger of a krab being cross loaded over an edge. Prefer fatter (10/11/12mm) sling to skinny 6mm dyneema , but dmm results (note with new kit) are still promising.

BD dont use a thing extendable sling as a big fall will deform the loop wire
(don't think they broke any) and repeated falls may break it. its on their site somewhere!
duchessofmalfi - on 23 Jul 2013
If you lark's foot it there is ~50% strength loss in the sling but it is still pretty strong, if you double the sling I can't see there being any loss. At ~50% a sling typically has 11kN left which is better than lots of gear and over typical leader falls forces.

It can have advantages in fairly obscure situations / placements but generally people don't use it because a double crab end quickdraw is easier, quicker and stronger.

I've generally only used this on belays if I'm running short of gear, I either belay or lead I'd try not to be relying only on one lark's foot. I think if you did it a lot or for perma gear you'd worry about the wire abrading the sling.
deepsoup - on 23 Jul 2013
In reply to Dervey:

That's pretty definitive then. Thanks for the link. :)
CurlyStevo - on 23 Jul 2013
In reply to RomTheBear:
> (In reply to kingjam) As far as I know it is acceptable pratice if abseiling off it, but I wouldn't trust it to hold a hard lead fall.

see link above yr post from DMM its actually pretty strong!
CurlyStevo - on 23 Jul 2013
In reply to duchessofmalfi:
> if you double the sling I can't see there being any loss.

did you not bother to follow the DMM link before posting?

GrahamD - on 23 Jul 2013
In reply to kingjam:

Actually the larks foot is the biggest problem in that set up. A sling just threaded through and both ends of the sling clipped is much better. Someone had a link to some test results a few years back.

If the alternative is a) no gear or b) a krab over an edge its a no brainer. Do it. If you fall badly you might have to bin the sling afterwards.
CurlyStevo - on 23 Jul 2013
In reply to GrahamD:
"Someone had a link to some test results a few years back."

does no one actually bother to read threads anymore, I give up....
martinph78 on 23 Jul 2013
In reply to CurlyStevo: I'm surprised no one has linked to this yet:

http://dmmclimbing.com/knowledge/improvisation-larks-foot-or-basket-hitch-vid/

;)
GridNorth - on 23 Jul 2013
In reply to kingjam: I thought that the OP was concerned more about the cheese cutter affect of the wire on the tape rather than whether to use a larks foot or a basket hitch.
CurlyStevo - on 23 Jul 2013
In reply to GridNorth:
did you read the DMM link? Only that it clearly goes in to detail, the OP is talking about using a larks foot and the wire can cut through that too easily, however a basket hitch is basically strong enough for nearly all real world falls.
GridNorth - on 23 Jul 2013
In reply to CurlyStevo: Yes but I just picked up on the first part of the post: "I was told this weekend that threading a sling directly into a wire ( instead of use a crab ) was a bad thing" i.e. I took that to be the primary issue in question but you are quite right to point out the larksfoot problem.

I have never understood why people larksfoot trees I would only do that on a stump if there was a chance of it lifting off. The problem with a larks foot also is that there is a good way and a bad way to orientate it.
lithos on 23 Jul 2013
In reply to GridNorth:
>
> I have never understood why people larksfoot trees I would only do that on a stump if there was a chance of it lifting off. T

better off with a clove hitch on a stump / stake than larksfoot. Stronger and wont lift off
stonemaster - on 23 Jul 2013
In reply to Martin1978:
> (In reply to CurlyStevo) I'm surprised no one has linked to this yet:
>
> http://dmmclimbing.com/knowledge/improvisation-larks-foot-or-basket-hitch-vid/
>
> ;)

Mercy!!.....:)
cuppatea on 23 Jul 2013
In reply to kingjam:

There was a thread about this quite recently. The main question was how to avoid a krab bending over an edge.

IIRC the basket hitch was stronger than extending the wire with another wire.
CurlyStevo - on 23 Jul 2013
In reply to GridNorth:
larks foot isn't as week as you think, if it avoids 3 way loading a biner I would do it every time, its still good for over a tonne (probably much more around a tree as its likely quite high friction around the trunk)
stonemaster - on 23 Jul 2013
In reply to CurlyStevo: Standard practice across the pond, they call it the girth hitch, one believes.
kingjam - on 23 Jul 2013
In reply to kingjam:

Thanks for all the posts , doesn't seem like the sling shearing point has come up that often ( barring overload ) , assume its a red herring .

From the DMM video it looks like its safe practice as long as you understand the reduction in protection and that a larks foot is a worse way to attach the wire than a basket hitch, purely due to the loss in force protection ?
kingjam - on 23 Jul 2013
In reply to kingjam:

Also the DDM test shows a wire being used as a extender , is this purely theoretical or practical ?
martinph78 on 23 Jul 2013
In reply to kingjam:
> (In reply to kingjam)
>
> Also the DDM test shows a wire being used as a extender , is this purely theoretical or practical ?

Done it once, then forgot about it. If it's a sharp edge it's probably a better option than a sling for extending the nut placement.
CurlyStevo - on 23 Jul 2013
In reply to Martin1978:
but then a basket hitched sling has a lot of material, you could ofcourse overhand the sling too after basket hitching it and / or double it up (before basket hitching) to increase strength further.
brices - on 24 Jul 2013
In reply to johncoxmysteriously:

this video may help to explain I guess a larks foot could behave the same as a overhand knot in relation to the test results?

http://blip.tv/a-fuerza-de-plafon/dyneema-and-nylon-drop-tests-4509845
MJ - on 24 Jul 2013
In reply to kingjam:

Also the DDM test shows a wire being used as a extender , is this purely theoretical or practical ?

I've larks footed two wires together before so that I could reach a higher placement.
Can't remember how I clipped it though.

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