Choked Biner Rigging

cbachmann said:
...the light-weight gate on that hook?
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I put a piece of rubber tubing over it so the slings don't get damaged by it, but they have never been a problem. Never broken one or anything. I've seriously bounced stuff around in there, too, rigging with the AFB and RnW when I'm working solo, since I really can't run the saw and control the load at the same time. That hook profile was developed to avoid that problem (avoid, not prevent) which is why it's about the only one used on these style hooks, regardless of who makes them.

I can see where negative blocking with really big stuff might bounce the sling around in there enough that it becomes an issue, but I just don't think it's likely. When the hook loads, the shape pulls whatever is in there away from the gate... much better than any carabiner because there's not that much room in there for stuff to be unloaded long enough for things to get sideways.

I have a feeling this has been tested heavily, but I can't find anything about it, other than a description/explanation of how the shape keeps the sling/chain from bouncing out of there.
 
I've seen this technique used in magazines videos and talked about a lot on here. I've never used it because i just feel instead of having one potential risk of failure the rope now your adding another in. for tight land zones taking small pieces i guess it could be quick but for bigger pieces even if you use a half hitch before it i wouldn't.
 
Everyone wants the strength of a spliced eye on a large bend radius, and wants to move the eye around to avoid repetitive loading.

I feel the shizzle is a good tool and have been puzzled by the lack of rating for negative blocking. I have not used one.
 
colb said:
Everyone wants the strength of a spliced eye on a large bend radius, and wants to move the eye around to avoid repetitive loading.

I feel the shizzle is a good tool and have been puzzled by the lack of rating for negative blocking. I have not used one.
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They seem to be worried about things going wrong with their toys. They won't let me run one of those beautiful rigging plates on my double bridge, even though the rating is well above the usual mbs.
 
Steel biner for almost everything here, loop runners then just a half hitch on the biggish wood.
I run a tight eye on some 9/16" that works great with the rigging rings for blocking down wood. Just unclip the biner and the eye goes right through.
If you're worried about smashing it then set it off to the side and let your half hitch be inline with the block.
Gotta love the extra weight when you're flipping it around a stem, until it busts you in the face.
The one drawback I have come across is the lack of friction you would have with a running bowline when you are lacing up a chunk. The biner wants to droop with any amount of slack.
 
Z'sTrees said:
The one drawback I have come across is the lack of friction you would have with a running bowline when you are lacing up a chunk. The biner wants to droop with any amount of slack.
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An extra turn around the piece will alleviate the droop. I always take an extra when I can.
 
i'm all for sling choked around spar to krab to rope as modular efficiency.
>>can group, preset krab/slings etc.; speedline.
>>uses for krabs/slings go far beyond this
>>one of the best things i ever did was commit to taking slings/krabs up with me!
.
i also believe that a single leg choke (w/ or w/o krab) is not mechanically correct on inline spar pull.
Should only use single leg choke attaching to load perpendicular/across;
>>Else modify to correct angle of pull with preceding Half-Hitch((HH) or Marl (s) as Tom says.
ABoK chapter_22:Lengthwise Pull (pre-ramble/opening statement):
"To withstand a lengthwise pull without slipping is about the most that can be asked of a hitch..."
>>these mostly have Half-Hitch and Marl preceders or Rat-Tail type strategies
>>and does encompass our Friction Hitches as inline pulls on a host rope rather than spar(so very familiar forms!)
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Also preceding with HH or Marl takes hit off the final choke/krab.
On lighter loads i'd say krab choke ok, but precede with HH or Marl.
HH/Marl preceder doesn't have to be around full spar, can be thrown around strong branch base etc.
.
Round sling choke is more dual leg to me, 2 grabs and handles inline pull on spar better.
But still for greater than moderate loadings, i precede w/ HH or Marl strategy.
.
HH ,Marl to me ; keeps the 'pure inline' mantra on the primary loading ,
>>as Bitter End exiting HH or Marl is inline with Standing Part entering.
Rat-Tail / VT braids type strategies give 2 legs of line at friendly angle for loading
>>favor 30degree spread in legs max, for 15 degrees from pure inline each
>>i call this the Same Zone (under 30 spread = under 15 deflection ea.) as almost as good as 2 inline legs of support.
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i'd only use steel krabs for this, good throwing weight too(as noted).
Always favored keeping steel krab in rigging eye for attach to belt, throwing and knotless rig as we talk about.
But still carried dynema slings on krabs to use most of the time.
 
Working for myself, tying knots for all rigging seems like an unnecessary time and energy killer. The fastest knot tier in the world just can't keep up on the small stuff. For light rigging I like a 50kN steel biner on an anchor hitch choked around the load or attached to choked slings. Throw in a marl when things start getting a little bigger. We used locking steel rope snaps for years with good success as well though most are only rated around 23kN.

Heavy and negative rigging - RB & marl.

If you're working for someone else - do as the Romans do.
 
I've watched a running bowline as well as a choked 'biner loosen if not come completely off when the piece being lowered encounters resistance when coming down. A green groundie who lets it run, but seizes the load can create a bungee effect. I watched that happen with the running bowline 15 years ago. The limb bounced up, the loop opened, and the 5 inch Oak branch went clean to the ground. Thankfully it rebounded away from the garage (and lined up with the chipper), but it could easily have hit it instead. Ever since, I've always taken two turns when there is no natural capture (union, crotch, tag-line, etc.)
 
From the looks of that 'biner and the termination knot, and the size of that piece of wood, I'd say it was getting clobbered against the tree hard. That's bigger wood than I'd want to have on there with a 'biner. The hooks I use on the 5/8" ropes are rated several tons SWL and the ones on the 1/2" ropes are 2.5 tons SWL if I remember right. The weakest link on those things is probably the steel pin.

That's just too much weight for a 'biner, especially negative blocking. I can't help but wonder how far the wood dropped, or if the groundman let it run. That 'biner was just flat ripped in half!
 
Tha
Oroboros said:
I went and found the thread where they broke a steel biner.

http://www.treebuzz.com/forum/threads/broken-carabiner-check-it-out.24131/
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Thanks for posting the link @Oroboros.

Regarding carabiner ratings of 50kn or whatever, it seems like many guys forget this rating is for an online pull on the long axis. They are generally rated for 7-10kn on the short axis. But to my understanding, carabiners are not tested (or rated) for any type of crossloading force. This is the root of the problem, because at some point, that load will break the carabiner.
 
This steele biner has been used very little, it was a gift, it's only 25kn, but I only use if for limbs, nothing big at all, it's never been shock loaded, see what I see and feel? Noticed it after using it today on very small dead Maple limbs, yes I choke them, but I'm pretty consistent about making sure it's not side loaded. I could have missed this from the previous job, but I check them before each use.
 

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