Knotless rigging (caribeaners)?

[John Paul Sanborn]

Using a carabiner as a connector between a rope and a sling is good practice, using it as a choking connection puts it in an application counter to it's design. I've seen them open.

I used to advocate sling connections in rigging as faster for inexperienced groundmen to cycle the rigging line back. Then I figured out the Daisy-bo'lin I've talked about in the past, which some ArborMaster guys teach as a bunny-bo'lin.

Being a running slipknot, even the densest of labor types can figure out how to release the load after a few turns. "Just pull the friggin tail you useless waste of (insert favored expletive), how many time do I have to tell you!?!"

 

[treesandsurf]

JPS, do you have any pictures or links for the 'bunny bowline'. I'm imagining a bowline with the last portion of the knot a bite rather than running the end of the line through?

jp

 

[John Paul Sanborn]

JPS, do you have any pictures or links for the 'bunny bowline'. I'm imagining a bowline with the last portion of the knot a bite rather than running the end of the line through?

jp

Why i call it a daisy is because it is a series of bights tied like a running bo'lin.

I'll try to find the pic's, but your smart enough you can figure it out yourself.

 

[tree md]

When I daisy chain I use a series of claw hitches, I believe that's what it's called, it was taught to me as a "cross claw" and terminate with a running bowline. I have seen others terminate with a cross claw and use it just like a running bowline. It's a little more simple to tie and won't bind when loaded. The advantage of the running bowline over the cross claw is the groundie can pull the knot to him and untie it. Anyone who can't figure out how to untie a running bowline on my crew doesn't last long. I do use a biner on a sling and terminate with a knot to rig smaller stuff where weight is not an issue but for heavy wood I will use a block and tennex sling using a knot to choke everytime.

 

[Mike Cantolina]

I use slings and biners up to about 9"-10" diam. A running bowline with a marlin when bigger than that.

When I use a sling as a false crotch I often use a second one as a backup and redirect often.

 

[Raymond]

:computer: I've considered this in the past. But then I don't think I would want to use it every time and I sure don't wanna set up two different ropes.
Here's one you can give me a hard time with.
I don't even know how to tie just a bowline. I use a running bowline on everything even right there in front of me. With a wrap around on the big wood.

 

[John Paul Sanborn]

Here is a pic of the daisy bo'lin tied. As you can see it is a series of bights passed through each other.

Since the load is not on the lock of the knot, it will untie even after very heavy loads are worked.

The onlyntimes I've had problems is when I do not tie or dress one right on a strong pull.

 

[Raymond]

QUOTE=John Paul Sanborn;1417660]Here is a pic of the daisy bo'lin tied. As you can see it is a series of bights passed through each other.

Since the load is not on the lock of the knot, it will untie even after very heavy loads are worked.

The onlyntimes I've had problems is when I do not tie or dress one right on a strong pull.[/QUOTE]
:computer:So what's the reason for this knot? Not looking for trouble just a little education..ya know?

 

[outofmytree]

If I understand the question correctly, we are talking about wrapping the rope around a branch or other chunk of wood to be cut off the tree and using a steel biner to secure the terminal end ( tied to the biner, or spliced ) back to the standing line. Yes, this will result in side bending loads on the biner. This is probably the weakest axis you can load the biner on. As someone said earlier " it will work till it fails". I would carefully check after each use for any signs of bending such as the gate not completely closing on its own.

Yes I regularly check my rigging equipment just as I check my climbing gear and in fact all my regular working tools. I think all competent professionals in high risk work places would do the same.

Side loading on the krab? In order for SIGNIFICANT side loading to occur you would have to have to wrap only once, as each turn adds friction thus reducing load, and to exceed the wwl or swl or at very least approach the swl/wwl of the krabs. The steel krabs I use are simple screw locks with a 15kn side load rating. Can you give me an example where a double wrapped rope secured by spliced eye or knot would place a side load on a krab in excess of, or even approaching (3300lb)1500kg??

Whilst this in under discussion why are we talking about side loads on krabs? Unless there is slack in the rigging all my krabs are secured end to end. That is, tied at the bottom and locked on at the top.

I am interested in the science being used here and if you give me a little time I am prepared to sacrifice a length of load bearing rigging line to test this theory. I suggest tying off to a serious tree stump and the back of my truck and hauling ass. What breaks first, the krab or the rope, should be interesting. I have little experience in setting up this sort of experiment but I am interested enough to give it go. Any suggestions would be welcome.

 

[tree MDS]

No offense to anyone... but I agree with dans original opinion that a caribiner aint meant to get mashed into the trunk as in blocking down logs.

Why mess with it if it aint broken??

I'd hate to put a log through someones house and have all the other cackling old hen treeguys rolling with glee just because I didnt feel as though I had enough time to tie a bowline.

If I cant use it for everything safetly as with a half hitch and running bowline, then I've got no use for it.

 

[outofmytree]

No offense to anyone... but I agree with dans original opinion that a caribiner aint meant to get mashed into the trunk as in blocking down logs.

This is getting repetitive but I will have to agree with Ekka twice in the same thread. Blocks are the reason God invented slings. To be frank, I rarely need to rig blocks as I have become adept at bombing straight on to bags, but the odd occasion where I do, then slings are going to be the order of the day.

The last time I put any significant load on my number 1 lowering line I retired all 45 metres of it and bought a new one. Not worth the risk of failure once it's shock loaded like that.

 

[outofmytree]

What you are saying about the load on the biner being reduced is only true if what the rope is wrapped around can not rotate. When used for lowering the load does rotate and an equal load is placed on the rope and biner. It does not matter if the rope is wrapped a dozen times.....If the load can rotate it does.......and automatically equalizes the force on the biner and rope.

Tying your truck off to a stump will not be the same experiment as tying off to an object that can rotate!

Sorry TreeCo but I don't get this. Maybe it's just too late at night for me. How does the load rotating on its axis, if indeed it can, change the direction or vector of force? Are you talking about a block or a branch? If you mean blocks only please refer to the post above. If branches then clearly I am in need of enlightenment.

Could you provide a sketch of what you mean? This would really help. Thanks.

 

[John464]

The steel krabs I use are simple screw locks with a 15kn side load rating.

Why use a screw locking krab? Wouldnt a self locking krab be more ideal since the whole point of using a krab is to increase efficiency. To unscrew and screw takes longer than tying a knot.

The same thing applies for using the combined sling and krab. It takes longer to loop a sling around a branch then snap the crab than it takes to tie a knot. Unless we are talking about taking multiple branches in one rig? Thats a whole other topic since the krabs positioning is different.

 

[outofmytree]

Why use a screw locking krab? Wouldnt a self locking krab be more ideal since the whole point of using a krab is to increase efficiency. To unscrew and screw takes longer than tying a knot.

The same thing applies for using the combined sling and krab. It takes longer to loop a sling around a branch then snap the crab than it takes to tie a knot. Unless we are talking about taking multiple branches in one rig? Thats a whole other topic since the krabs positioning is different.

Maybe a picture of the Krabs I use would help but I can't figure out how you would think that an activity which requires two hands and concentration is faster than an activity that requires one hand and well, we can all screw without thinking about it right?

Slings are occasionally slower but the reason for them is not speed but protection of hauling rope. Big fat Tuarts just mash up rope and if you MUST rope down blocks slings are simple to set, simple to undo on the ground and cheaper to replace than top grade load bearing rope.

I use screw locks because, without word of a lie, self lockers make some groundies screw up their forehead in concentration and then explode. Seriously. You would think opening a 3 way was akin to solving the meaning of life......

 

[outofmytree]

Ok. I think I see what you are getting at. So then the issue becomes one, not of the krabs strength but rather the effect of having a rope pass around a narrow object, (the krab), and the additional stress this places upon the inner radius of the rope at the point of contact. That makes perfect sense but would apply equally to a falling load or a constantly stressed load like the truck-pull experiment I suggested. As for the krab it self rotating so the load is "horizontal" rather than "vertical" as it was set, that is the point of double wrapping. The friction you gain ensures the rope doen't "slide" and also keeps the krab in its place.

Diagram soon please!

 

[Highclimber OR]

I use it on occasion, however lately I have been using the OSHA standard "Running Bowline" especially in risky situations. I have had caribeaners come undone before so I tend to stray away from that. My dad loved em though especially later in his career mainly for the convenience. BTW sorry all for the offensive "O" word in my post.

 

[outofmytree]

I'm talking about any load that can rotate be it a block or branch. Think about it........wrapping a rope around an object and pulling produces a rotational force.......the only way it would not rotate is if it's a fixed object......or if an equal force is applied so it does not rotate. These rotating forces cancel out where the rope meets the biner on an object that can rotate.

You need enlightenment! Diagram on its way.

Another thought and then bed for me. Where the ropes contact each other is another "narrow object" similar to the krab. So at point of shock loading, the stress is still going to be passed to the rope, only this time in 2 locations rather than 1. Hmmm. I wonder if the ratio of shock has ever been measured accurately on different portions of a knotted rope.

 

[John464]

Maybe a picture of the Krabs I use would help but I can't figure out how you would think that an activity which requires two hands and concentration is faster than an activity that requires one hand and well

I'll agree with you on that. when you only have one hand free a screw locking krab would be faster than tying a knot, and a self locking would be even faster than that(if your groundies are properly trained)

 

[Raymond]

I'll agree with you on that. when you only have one hand free a screw locking krab would be faster than tying a knot, and a self locking would be even faster than that(if your groundies are properly trained)

Why would you ever only have one hand free?

 

[John464]

Why would you ever only have one hand free?

I dunno. Sounds like poor work positioning to me, but I can not say for sure. Perhaps outofmytree can answer.

I personally bite a rope to free my other hand all the time