Knotless rigging (caribeaners)?

[Raymond]

You guy have me wanting to time my running bowline knot now.
I'll get someone soon to time me and tell ya what it took.

Bet it's under 5 seconds. I know I can do it with my eyes closed. I'll even time that.

 

[pdqdl]

With all of that rope around the lowered piece as slack is taken up there is going to be a lot of rope on rope friction, NOT GOOD!......way more than a marl and running bowline or marl and timber hitch.

What a cluster rig it's become!

When the block of wood gets laid on the ground it's not going to be very easy to undo either.

If you look at the drawing closely, you will recognize that it IS a marl (or a single hitch) with a carabiner (Krab) closing a loop on the bitter end, exactly like a timber hitch with a marl in front.

I suppose the biggest difference is that I always put a bit of distance between my timber hitch and the marl, as pictured way up this thread.

I don't see all the rope-on-rope friction happening as a problem, unless the rigging is left loose or you are loading the rope to extreme limits.

I just prefer the timber hitch over 'biners because it's less equipment to use, it's stronger, and I don't have to worry about dressing the knot/rigging too much to get it right. You don't use exactly the same part of the rope each time you tie, either.

If you close with a carabiner, you must work the rigging backwards to take out the slack. This will be a loss of time! Closing with a carabiner requires that you pull out the slack and work backward through your marl (if you are using one!) to get the tension right. Even a bowline once tied would require this step.

The timber hitch can be pulled tight from the tail, eliminating much of the extra tensioning steps.

 

[murphy4trees]

Even if such a small diameter branch weighed 100kg it would need to fall roughly 10 metres to generate 1000kg of force which is still only 6.5% of the krabs lowest rated capacity.

I would check your math there... 10'... not 10 metres, to generate 10x the force.. Though I understand those equations have been revised and the forces may be even greater... especially for drops over 5'..

Shock loading is a major concern for me when watching your videos Ekka... It's not so much the knotless system as the distance between the cut and the block... Your groundman has good technique to let it run as he does... You could still get yourself in trouble with that style though... Maybe he takes an extra wrap by accident or the rope hangs up on a bush or whatever behind the groundie, or it has a knot in it that catches on the lowering device, and the tree has a hidden defect... Or maybe you got a new groundie, or he just isn't paying attention cause he had a fight with his girl last night.

When you put 2-3' of distance between the block and the cut, that becomes 4-6' of extra (and unnecessary) drop... That extra 6' of drop can generate a lot of force.. Enough to cause failure and kill you in the wrong situation. Brings me back to the initial point... You got to understand the physics of falling objects in order to reduce shock loads. The cavers and rock climbers are way up on this stuff. Links to some of their sites were posted here many years ago..

So the distance between the cut and the knot has little or no effect on shock loading... You can still use the knotless system though, which I like!!!, (and will get around to incorporating this year hopefully)... The key factor is the distance between the cut and the block. So you can tie the sling on high enough to make room for the sling and biner without effecting shock loading..

You seem like a great tree guy and real good person as well Ekka... I'd hate to see you get hurt or killed.. I usually make the cut and then tie the block as close as I can before lacing up the piece.. Some guys tie the block first then make the cut. Either way, when it is your life in the balance, keep that block right up next to the cut..

Hope that helps

 

[Ekka]

:chatter:

Yawn.

 

[outofmytree]

Well explained mate. This is possibly an issue for krabs used on branches whose diameter is less than "length" of the krab, however for branches that small I cannot see how the shock generated could have any adverse affect on a steel biner. Even if such a small diameter branch weighed 100kg it would need to fall roughly 10 metres to generate 1000kg of force.

Apologies all for this typo on my part. It is correct that an object falling gains roughly 100% of its mass for every FOOT it falls. I am so used to typing in metres and kilograms I missed the translation. Thanks for spotting this Murphy.

That said, I still havent seen anything except "I do it this way because I was taught this way" arguments. I havent bothered to time myself but if you take a krab (carabiner) and swing it underhand onto a branch it wraps itself around twice in no more than second. Could it take 4 seconds to open and close a screw gate?? Exactly how much shockload do you think a steel krab will get when locking off a rated hauling rope in the manner drawn previously?

Treeco I asked you to provide information to support YOUR argument. Thats how its done in debate. I have told you exactly what I do and the items used and provided the load rating for the krab. I am asking you to provide any data to support your as yet unproved theory that the shockload in a typical branch removal using a rated hauling rope, a rated pulley and a porta wrap will "bend" a krab. I have looked and can't find any data that suggest this is possible or even likely. I could use the argument that I have done hundreds even thousands of drops using this technique but you would say the same about knots and we are back to square one.

 

[outofmytree]

Actually man on occasion I've used biners in the fashion you are describing for almost 20 years! I just don't use them for heavy loads. Before I was using biners I've even done it using non locking climbing snaps.(remember them?)A technique I like better than what you are doing is to use a sling and a biner with a bowline in the end of the rope. Wrap the sling around the limb and clip the biner into the bowline. Often I can catch several small limbs at once and lower them as a 'cluster'.

I've got a new use for old biners. In the barn out back I'm using one to bridge the gap in a fuse box that has been damaged and no longer will hold a fuse.

I've searched manufacturers data and can't find a damn thing on my novel application! It seems to be conducting well and unless you can provide me data that says I'm abusing the biner.........

I smell smoke.

That's a novel approach. You could always try the more direct response of "actually I can't prove you wrong but I will go on believing it because!!!!"...

 

[Ax-man]

I am not into rigging with biners being used in place of a bowline. It looks like Ekka may have worked around the issue a little with his drawings but I sure wouldn't want to have to undo that method with a big piece of wood laying on the ground or on top of a pile of lowered logs. Too much pulling of rope from underneath the log.

Loops made out of Tennex with a biner connection to the lowering rope work good for the smaller stuff. Once the brush is off the tree and all that is left is the wood to be lowered a bowline works good. No need to really untie the knot. Just pull some slack and slip it off the end and send the knot back up tied and slip it back over the next piece. What is so hard about doing that?? The only time you need to untie the knot is if the piece is too big for one person to move or is tied in the middle and needs to pulled out from underneath the work piece.

Larry

 

[outofmytree]

What is tennex??

 

[Ax-man]

I put an extra --n -- in the name by mistake

http://www.samsonrope.com/index.cfm?rope=174

 

[outofmytree]

http://www.sherrilltree.com/Professional-Gear/Eye-Slings-For-Blocks-/std_Islg_tenex_12




Did one extra 'n' throw ya?

Yes it did. That and the couple or six beers I have guzzled. It looks like the same material my whoopies are made of. Come to think of it the sling we use for the porta wrap looks to be made of the same stuff too. Tough stuff.

 

[TreeTopKid]

Yes it did. That and the couple or six beers I have guzzled. It looks like the same material my whoopies are made of. Come to think of it the sling we use for the porta wrap looks to be made of the same stuff too. Tough stuff.

It is I love whoopies, and use them for a multitude of uses. My favorite being using as and anchor for ratchets to straighten windblown trees. There was so much big timber down people were walking away from straightening small trees after the last big storm. I devoted two days to it and made a pile. Without the whoopies it would have been a much slower process. Those things are super strong.

 

[pdqdl]

...No need to really untie the knot. Just pull some slack and slip it off the end and send the knot back up tied and slip it back over the next piece. What is so hard about doing that?? The only time you need to untie the knot is if the piece is too big for one person to move or is tied in the middle and needs to pulled out from underneath the work piece.

Larry

Good point. I had never considered that. Partly because I always use a full hitch in addition to whatever knot or 'biner I am using to close the loop. Shorter logs can't fall out, no matter how much they bounce around. Sometimes a simple choker loop falls off the end of the falling chunk of wood.

Oops!

 

[ropensaddle]

What I saw Ekka in your vid I like endless loops but I would be a little closer to the butt to prevent getting clobered when the groundie can't lower fast enough or read your mind. I started getting closer to the butt after a nice limb gave me a kick to a rather private place years ago. I will only tie out in tip tie butt heavy scenarios since or with a balance line added when necessary that is usually tag lined as well!