UKC

Question I was wandering about:

A lot of sport climbers have black rubber things around the lower krab of the draw and the webbing to make clipping easier. If you were using a trad extender - i.e instead of a nylon webbing you have a standard 60cm dyneema sling between the karbs - could you use a clove hitch to keep the lower krab from moving? It works fine for keeping the krab still, but is it dangerous for some reason? Would the clove hitch compromise the strength of the dyneema?

Thanks,
Adam

In reply to adam 24:

It'd weaken the sling. Possibly by a lot.

In reply to adam 24:

would it be possible for the biner to slip around the clove hitch and then it make cross loading more likely? I just leave my biners free floating on sling draws, they are designed to make cross loading very unlikely in this scenario anyway

In reply to Kid Spatula:

As you say the clove hitch could take it down to around the same strength as a cross loaded biner, as the sling ages it could even be weaker than a cross loaded biner!

In reply to adam 24:

not necessarily dangerous but the clove hitch will considerably reduce the strength of the sling, negating any advantage (assuming there is one to begin with!) to doing it in the first place.

In reply to adam 24:

It's only really an issue on pre-made quick draws where you want to clip it to gear then clip your rope in without hassle. If you're using a sling draw, you'll usually be lengthening it first so you can orientate the krab to be the right way 'round afterwards.

In reply to adam 24:

The biggest problem with clipping a 60cm sling is the fact that it's 60cms and can wave around all over the place. Orientation of the krab is less of an issue IMO. In the past I have used O rings to capture the krab at one end which is a better solution than a kot but you have to be aware of the risk of hanging just from the ring and not the sling. These days I tend to not bother as it got a bit tedious having to forewarn people who used my gear.

In reply to adam 24:

I use slivers of bike inner tube as O rings to hold the bottom krab in place and it definitely works better than keeping it unsecured

In reply to adam 24: Hi Adam

Article here says clove hitch reduces strength to 65%, http://www.climbing.com/climber/10-things-you-didnt-know-about-knots/

So with a new sling this still translates to at least 11kn.

I regularly use sling draws with both binders free, and I feel by doing what you suggest you negate the great way you can lengthen shortened draws by simply unclipping one biner and just clipping any single section of the sling.

So I'd keep both binders free.

HTH Davy

In reply to csw:

unless of course this happens
https://www.thebmc.co.uk/deadly-quickdraws-open-sling-rubber-band-accident

In reply to CurlyStevo:
I check my gear before I use it. It's pretty obvious when the sling has twisted itself into the lethal configuration. The chance of it happening and me not spotting it is nowhere near enough to discourage me from configuring my extenders like this.

In reply to csw:

although when its tripped up as an un-extended sling draw it could be a lot less obvious. Personally I don't think the advantages of the rubber ring outweigh the disadvantages (especially for sling draws).

Stevo

In reply to CurlyStevo:

Well - I see it the opposite way, so I guess we can agree to differ on this one. With the rubber in place the chance of the bottom krab turning in the sling is pretty much eliminated, and with it, the chance of cross-loading, or the gate contacting the rock and opening under load. Believe me there's no way you can miss an extender with a keeper ring in a dangerous configuration, unless you're not paying attention when you check your gear - and anyone who's that unobservant is going to find a way to kill themselves at some point, no matter what gear they use.

In reply to csw:
I can't see how the rubber ring has much effect either way on the gate contacting the rock.

Also what you have to weigh up is the pretty unlikley chance of cross loading a biner (this could still happen anyway on your sling draw when used tripple up!) and the consequences of this (probably nothing most my biners are nearly as strong cross loaded as the gear I place and in some cases stronger). On the other hand you have the even more unlikely chance that you may miss the issue WC / BMC highlight which if you do could be terminal (as it was for the young climber that died recently)

I use sling draws and I think it would be hard enough to spot on a tripled up sling draw that I wouldn't keep one end captive. I'm not the first poster on here to say this either. I'm happy to use this sort of thing on normal open sling quick draws though for the time being, but in future I do intend to only buy closed loop quick draw slings (if I want one biner captive).

In reply to CurlyStevo:

If you place a runner with the gate facing away from the rock, and the krab turns in the sling from rope movement, then the gate's facing the rock and the possibility exists it might open during a fall - the chance of this happening is greatly reduced by keeping the krab at the rope end captive.

Anyway, we weigh up the issues and we make our choices. I think this is where we respectfully agree to differ on the subject

In reply to csw:


But many have. I have used them and if you are aware of the potential for misuse using them is no more dangerous than many other things that climbers do. As I said my concern was more to do with when I handed on my rack for a partner to lead through.

In reply to adam 24:
It seems as likely to me to make the mistake of the video as making the mistake of using a clove hitch (ie most people would know this) so in your case Adam i'd concentrate on hanging the krab with the rope coming out the right way on the correct length extender first. If you find that this doesn't satisfy you then buy the purpose made quick draws.
To adapt if necessary will be very easy on the day, rubber band or insulation tape.
If you don't know what I mean by hanging the krab with the rope coming out the right way.. check it out at a wall or crag next time and not later.

jimb

In reply to adam 24:

Thanks for the replies - the clove hitch reducing the strength of the sling was what i suspected might be the problem.

I actually wasn't considering this for a trad route, but for a sport route with a very pumpy clip position. I wanted a longer draw so i could reach it from a better hold and having the gate steady would make life easier still. I'll just extend the draw the normal 'sport' way (if i can borrow my mate's nice draws again) or use a carefully placed rubber band.

In reply to adam 24:

You could always use a cheating stick. I made one by threading a 30cm 6mm sling through some thin plastic tubing. I then secured one of those krabs that you can hold the gate open to the tubing via rubber almagamating tape to one end. I cut a notch in the tubing to encourage it to stay in place. This is also used as a clip stick by attaching it to the end of some tent poles with steel wire through the middle which acts a "draw string". Cheaper, lighter, more compact and better than a commercial clip stick as well as having a dual purpose.

In reply to adam 24:
If this is a worry then use a screwgate bottom half to your extender?

In reply to adam 24:

Wouldn't a clove hitch cause only one half of the sling to be brought into play in the event of a fall as well, since the system wouldn't equalise on both sides of the sling ? If the 'biner was free to move along the sling under load it would balance out the forces... or have I missed something ?

In reply to paul walters:


Think about what's happening at the other (non-clove hitched) end of the sling.

In reply to adam 24:

I don't see how a clove hitch would help much... dyneema is pretty slick stuff and the clove hitch won't be tight until its loaded. The rubber stuff has high friction and is snug on the binner... what you describe will have none of that so really it won't keep the binner from moving around when trying to clip.

In reply to adam 24:

See the DMM test here on dynema and nylon slings with clove hitch.... doesn't really change the forces.

http://dmmclimbing.com/knowledge/slings-at-anchors/

In reply to Mountain Llama:









Seems to me it's quite likely that that strength reduction number is for a test case that is different to the OPs configuration.

In reply to needvert: I think the strength reduction due to knot in the sling is a red herring. If the sling is in good condition and it's strength is reduced by 50%, this still leaves 10kn in the bank.

In reply to Mountain Llama:

why would you actively start reducing your margins?

In reply to franksnb: imho what the OP was suggesting is not a good idea but we all tie knots in ropes and slings which results in strength reduction. I guess that's why slings and the like are rated so high in the first place, ie 22kn