X-Rigging Slings

[kevin bingham]

Thanks for pointing us to the original rings. I was very close to spending the money on a sling I didn't want and would have cut off. His product is "rings with slings", not the rings. I imagine he signed a contract with Antal or something that he would not sell them without slings. I don't see whats so hard about just saying as much. I personally love the idea of these rings. These seem light and simple, cheap, and strong.

 

[treesmith]

I was mulling these rings over in my mind today while riding down the road and I have a query to put forth.... As we all know, a block has its own mass/weight/etc to positively render it a damper on any slack flung into the line by a rigging scenario. These rings, on the other hand....is there a possibility of them "floating" in the snap of the rigging line and allowing a hockled line to foul? You know how a hockled line has the twisting tendency; would it be possible for a hockle/twist/etc to "grab" in one of the rings and cause any sort of complication? Just a thought...might be nothing to it. I wouldn't mind having a couple of them to make a R&R rigging friction saver, but would only use it when setting it remotely was practical. (Or when having to go back up and retrieve a block was NOT practical.)

(I'm referring to the use of the rings as in the fish pole diagram Nick pasted, assuming they were choked and the line were run vertically through the single ring like the guides on a fishing pole. Seems they would be sort of "hanging" there riding the rope.)

 

[Tucker943]

Tucker, this is not right. This excerpt is from a Rigging Forces article in HSE Research Report 668 by Detter, Brudi, et al (Read: Big ass, complex, lot-of-math report.)
Bold-emphasis within this excerpt is mine.

David



However, rigging operations
will always generate considerable bending moments on stems, due to the angle of 32 to 42° at
which the peak force occurs in the lead of the rigging line.Secondly, the log still has considerable
speed when the peak load occurs and will gain even
more as it accelerates during the pendulum swing towards the stem.

I stand corrected. But let me ask, are those studies done letting the log shock the rope? If so, throw em in the trash. If they're done with groundman lowering off of a friction device, then the results will vary wildly based on the style and timing of each individual. The force created if you shock the rope is nowhere near the force created if the load runs freely and is brought to a halt smoothly before touching the ground.

 

[Tucker943]

How did they choose the human to use in the study to operate the friction brake? Was he skilled?

Knowledge is good. If your data is truly applicable to rigging wood through a humans hands and then through a bollard, then through a block, then Im truly surprised and have learned something important. If they set up a weight in a lab and dropped it onto a block with a scale and measured what did what and when it did it, then its useless to me. That's not how I put wood on the ground. If I block a log down and my groundman offers no brake on it until it has almost reached the ground, then how on earth does it generate a peak force between 32 and 42 degrees. The rope doesn't feel crap until the human offers resistance. At that time, the rope becomes loaded. I want to agree to the data you've offered but first we must make sure it relates to rigging in a tree with a groundman in control, not in a lab.

 

[treesmith]

Chris, take your newspaper pic for example. The instant the pic was snapped, the forces would have been outward and downward, with the spar absorbing that force/momentum, then rebounding in the opposite direction, which is often when the piece slams the trunk, multiplying the "felt" jolt. Though a competent groundie can overcome these forces greatly, unless there is ZERP resistance on the rigging line, the stem will feel some of the pressure the instant the line goes tight.

 

[Tucker943]

I agree. You are right. Lets keep in perspective how much force it really feels in relation to when and how the groundie hits the brakes.

 

[Tucker943]

Im like the lone man in the alley, surrounded by a gang. LOL. Its all good. I like a good debate.

Rep VS Dem anyone?

 

[Bushwackertree]

I have never had this problem treesmith, as most of the time the rope has already run through the lowering device. As DMc had said in his post explaining the forces, the main source of your stem flex is not only when the top is caught but more as the top has broken the hinge wood and is traveling out and away from the trunk as your rigging system starts catching the top pulling it back towards the trunk.( As the load line increases, the stem starts to bend forward under the load being applied at the anchor point.) Yes you can limit the amount of sway but letting it run or not but stem movement is started before the top is ever caught. I think this subject will be beat like a rented mule, and could be discussed til were all blue in the face. We all have our own styles, equipment, and practices we use. I dont think of it as over rigging more so smarter rigging.

Ben
Bushwacker Tree

 

[rangerdanger]

This is all interesting stuff to read. I see both Tucker's point and the other ones. Here's how I see it.

When the piece is going over, you have the force of the piece pushing back against the trunk via the hinge wood. As the piece goes over and the hinge wood breaks, the piece is now in free fall and the trunk may wobble a bit due to the force the hinge wood and piece created. As the slack between the piece and block is taken up by the falling piece, force begins to be excerted on the block and the trunk. How much force is all dependent on how much the ground man let's it run. But a force is excerted, because the lowering line is run through a friction device on the ground, therefore the piece is slowed down, even just marginally, but it's prevented from a total free fall, so a force has to be on the block, no matter how small. As the piece comes parallel with the trunk, the small outward or downward force becomes a downward force and more weight is put on the block and trunk. Then it slams into the trunk usually, creating a lot of that wobble. A good ground guy will minimize all of those forces by letting the piece run and slowly braking it.

So to me, I guess I can see a small outward force being applied, but in my mind it's not enough to matter as long as the groundy let's it run.

 

[MasterBlaster]

The "Catapult Affect," from Jerry B's Fundamentals comes to mind.

 

[treesmith]

Regardless of how you define/explain it, those forces are real. And often it's compromised places that concern me more than just a top being skinny. I took down a rather dead poplar for Carl last year that I wouldn't let my groundie run the ropes on. I insisted that Carl do it. I was not positive I'd still be there when all the dust settled. It was one that sticks in my mind.

 

[Tucker943]

I think its safe to say that tree rigging is more complex then we can measure. No two pieces put on a rope will ever be the same. Different piece, different crotch, different block, different groundman, different species, etc. It all boild down to "what can I get away with safely?" We gather a small bit of that knowledge from science, and the other 99% from experience.

 

[DMc]

... But let me ask, are those studies done letting the log shock the rope? If so, throw em in the trash...

This study, as do most of the ones I have read, deal primarily in worst case scenarios: e.g., snubbed loads, so they can get some kind of repeatable numbers. But even so, you do not want to " trash " it. It is a massive report, chocked full of useful information. They did cover the topic of letting it run as a means of transferring energy, as we know it does. Though reduced, there is still a lateral component that must be dealt with.


Dave

 

[Tucker943]

Im with ya Dave.

 

[CurSedVoyce]

The "Catapult Affect," from Jerry B's Fundamentals comes to mind.

Paddle balled

 

[DMc]

Anyone that has a spare 16.7 MB of space can access this report here.

http://www.treestuff.com/knowledge.asp?knowledge_id=14

Dave

 

[bonner1040]

All 390 Pages! I found it amazing that you were able to quote it Dave!

 

[SouthSoundTree]

Fishing pole rigging is not best illustrated on a vertical spar. The best way to demonstrate it on a vertical spar was, IMO, to super overload a skinny pole.

This is not for day to day rigging on vertical spars. If you have to tie into a smaller live tree or high line nearby a dead skinny thing, and take a big top, as it is as high as you can get due to your TIP, it can help. The more fishing pole eyes, the better. It would have been interesting to see that 900 pound log on that spar with triple the number of eyes (other, lighter weight rings, snugged up to the trunk maximally would have been sufficient).



The wobble from a piece slamming the trunk is different from the push back and pull forward of a hinged top going over. As pointed out, IIRC, in Art and Science of Practical Rigging, an bird beak 70-90 degree facecut is the best for tops, as is results is less push back and pull forward. Most trees I work on, it doesn't matter, and what's a little ride, anyhow. Plus, when I have an expected larger ride, like a tall and skinny thing, I leave some dampening branches on the stem below the facecut and maybe lower on the stem. Again, an exception.




As a fishing pole redirect, there are a lot of things that would suffice, that are probably already in the bag.



For a light rigging point, bigger than a carabiner and burlier than a small pulley, the X ring(s) could be good. Blocks and full sized slings are bulky. A big ring spliced on smaller tenex for light rigging could offer compactness, lightweight, and a decent (better than biner) bend radius.


I, too, like the LD up top if I need to reduce the force. The BMS Belay Spool works well in this scenario, as well as a porty can. BS is more compact, and I already have it on a spectra sling which makes the whole thing light and compact, relatively.

 

[CurSedVoyce]

That was my interest in them Sean, when I first saw them... Light rigging and quite light and portable for the climber. Good redirects.....

 

[Marc-Antoine]

Fishing pole rigging is not best illustrated on a vertical spar. The best way to demonstrate it on a vertical spar was, IMO, to super overload a skinny pole.

I agree.
If a top or log side loads a decent pole, the bending on the length is actually very small and the intermediate rigging points see almost nothing as a load because the line run nearly straightly throw them when loaded. So with the test load in the Xring's video, even with this small pole, the fishing pole rigging is absolutely useless from my point of view.

The fishing pole's principle begins working only with a very high bending diagram, when each intermediate rigging point causes a significant inflexion of the line. For real.
Like a big fish pulling on these skinny poles, bending them over than 90°. The best spread of the load occurs when the pole is enough flexed to have its top almost in line with the line. ( Do you see what I want to say? I don't know if my english can follow. )
This can't be the case with a straight tree, even skinny, because it's way too much stiff to bend that much.

There is one situation where the fishing pole applies well to tree work though. That's when the tree is already bended, if we can say that. The different tree's segments follow the fishing pole diagram, but in a fixed way (not dynamically as the true fishing pole), like having the rigging point away on a horizontal main branch. Many redirects following the wood path are useful in this case and the last rigging point sustains a smaller force, in opposite of the line running straight to the brake.

 

[bonner1040]

Indidvidual Rings are now available from Treestuff!

https://www.treestuff.com/store/catalog.asp?item=2235

I think the markup is reasonable considering that arborist specific user-support is available and you can get free shipping as always through Treestuff.

 

[emr]

So your balls got busted for finding the originals and they were going to be for sale as individual rings all along...... :confused:

I will be buying some of these next order.


Sent from my SCH-I535 using Tapatalk 2

 

[bonner1040]

Its all good..

 

[stig]

You are just a nasty, jealous vulture, it seems.

So am I, for putting the poor guy's video down.

I can live with that, I guess.

I'd rather be a jealous vulture than a wimp who tries to market an existing product as his own, repeatedly lies about it, then goes all whiny when exposed.

Sorry, I just read the whole thread on TB and got a bit more than mildly pissed off.

Good to get reminded why I quit TB.

 

[bonner1040]

David posted this response this morning: