new approach to midline loop winch connect .... Hardware

[preventec47]

I have some time to kill since I ordered and received the wrong rope for my project but I have been playing with my new Wythe More Power Puller and old
rope researching and trying different mid line loop solutions. At the full winch capacity without mechanical advantage I have irretrievably jammed two alpine butterfly
knots in my old 5/8 braided nylon rope. Realizing all knots stress ropes due to small radius turns, I started looking at some hardware solutions that would be less stressful and equally or more confidence inspiring. A home made Portawrap discussed in these forums gave me the idea... Take a look at these photos. The shackle cost $10 and is 3/4 inch in size with a 7/8" diameter pin and marked with a working load of 4 3/4 tons. The Figure 8 Descender $20 and the Caribiner $27 are both marked 50 KN. Today I will setup my test platform which is two big trees about 30 feet apart and take my winch and test the Artillery Loop, the Rosencinch knot,
bowline on a bight, and the Shackle midline loop connect as well as the Figure 8 Descender as depicted in photos. The rope used in the photos is 1/2" marine dock rope
used just for photos..
I would expect that either of these hardware options would weaken the rope less than using knots. There are some Prussik solutions on Youtube but I dont have short ropes needed to try them and dont know what size and type works best with the new rope I am getting in a week or so after returning the 300 pairs of chinese handcuffs. ( 300 feet of hollow tube Tenex Tec ) It may not be obvious but after wrapping the loop in the shackle, I took the loop tail and tied two half hitches around the main pull line. I would do the same with the Figure 8 Descender as a little extra insurance. Regarding the Figure 8 loop, I tried to wind the rope in the direction so that as
the rope is tensioned, it tightens on itself to create a lock on the rope and prevent it slipping. I am not sure if all the rope turns in the shackle will prevent slipping
so that is why I am testing and adding the extra half hitches. I have worn out a few chainsaws in my lifetime but I have never worked with taking trees down strategically
beyond yelling "TIMBER" so please excuse my amateur efforts at creativity. I would appreciate all suggestions ( and criticisms) as to how I can improve on any of these ideas.

 

[TheJollyLogger]

This is how I was taught to lock off an 8, simpler and more secure. I think you will also find the right rope is going to make things a lot easier. That rope you have there honestly looks a lot like safety blue, and I'm sure you've noticed how much easier it is to work with.

 

[windblown]

Regarding the Figure 8 loop, I tried to wind the rope in the direction so that as
the rope is tensioned, it tightens on itself to create a lock on the rope and prevent it slipping. I am not sure if all the rope turns in the shackle will prevent slipping
so that is why I am testing and adding the extra half hitches.

By no means do I know every possible proven way to rig a figure 8 for every situation. I've never seen the center hole used. I always assumed it was just a weight reduction feature and not intended or designed to be used to pass a rope thru. Is the photo of your rigged rescue 8 based on something you found online? If so could you post a link? If it's of your own design be very careful with it. When a figure 8 starts to slip under extreme load it can pinch a rope in two and heavy loads really aren't in their thing. Pretty big difference between locking off a climber and pulling on a rope with a 3000lb winch.

 

[pdqdl]

By no means do I know every possible proven way to rig a figure 8 for every situation. I've never seen the center hole used. I always assumed it was just a weight reduction feature and not intended or designed to be used to pass a rope thru. Is the photo of your rigged rescue 8 based on something you found online? If so could you post a link? If it's of your own design be very careful with it. When a figure 8 starts to slip under extreme load it can pinch a rope in two and heavy loads really aren't in their thing. Pretty big difference between locking off a climber and pulling on a rope with a 3000lb winch.

Long ago, I tried rigging a heavy log to my rescue-8 to catch it on a short drop above a stone wall.
As you pointed out, the narrow radius tore right through the rope and I had to repair the stone wall.

At least nobody was under the log...

 

[pdqdl]

As has been mentioned in the OP, the alpine butterfly can be hard to untie when loaded heavily.

I use the man-harness knot, as it doesn't ever jam, but it must be tied and set correctly to hold. The bowline on a bight doesn't have that problem. Both are pretty free of jamming under stress.

You'll find the man-harness knot difficult to find online. It is also known as the Artilleryman's knot. I learned it in Boy Scouts as the Pioneer Knot, yet it was never any part of their literature at the time. It's very easy to learn; even a ground-man can be taught how to tie it.

"Make a pretzel with the rope (like this...), then pull the bottom up through this ear of the pretzel. If it falls apart, you picked the wrong ear..."​

 

[preventec47]

By no means do I know every possible proven way to rig a figure 8 for every situation. I've never seen the center hole used. I always assumed it was just a weight reduction feature and not intended or designed to be used to pass a rope thru. Is the photo of your rigged rescue 8 based on something you found online? If so could you post a link? If it's of your own design be very careful with it. When a figure 8 starts to slip under extreme load it can pinch a rope in two and heavy loads really aren't in their thing. Pretty big difference between locking off a climber and pulling on a rope with a 3000lb winch.

This is purely an experiment of mine mostly motivated by the frustration two permanent alpine butterfly loops in my favorite long time 120 ft rope. I experimented with the same rope today
using the shackle and Figure 8 setups as photoed above but I only went to 1500 lb ie did not
add in mechanical advantage as I did not want to break my rope. when my new Stable Braid gets
here I will tension my new rope at 3000 lb with my pulley setup. My impression of the Shackle
is 100 percent positive as there is no way it can jam because the pins can be unscrewed. For the
Figure 8 it is prettier and lighter but it appears It would be easy to over do the rope over rope lock in mechanism as the rope tightens up and could result in the same thing as a jammed knot. I also tried another configuration of the Figure 8 as shown in the photos attached with even more rope over rope as tensioned to keep the rope from slipping. Tomorrow I hope to redo the tests and will take photos of the rope wrappings under great tension and see how I may need to redesign the load path through
the Figure 8 that will guarantee easy undoing. One minor annoyance is that the pin in the shackle will not slide through the hook on the More Power Puller winch because of the spring on the gate. The workaround is unscrewing the pin and sliding the pin through the middle of the hook as you reassemble the shackle. I do also plan to test the Artilleryman loop, the Bowlin on a bight, and the the Rosencinch knot as featured on Youtube. Regarding the possibility of the Figure 8 device
cutting a rope,... I dont think it possible on a 1/2 inch rope as I dont think any section of the Figure 8
is smaller than the rope so it couldnt be any different size wize than a knot in the rope. With a much fatter rope then I guess a small radius causing damage would be more likely.
Attached are two more configurations of Figure 8 showing how they were wrapped. There must
be dozens and dozens of differnt configurations and it could be possible to fine tune according
to the needs of each application. ie more or less round turns in more locations on the Figure 8 and overlapping or underlapping of the loops. The Wythe Puller at 3000lbs inclucing built in pulley
with another snatch block should produce 6000 pounds capability. I already have faith in the
shackles but I dont know about the 50KN Figure 8 device.at 6000 pounds.
It occurs to me there may be pros and cons of using hardware vs knots with the advantage of
not needing hardware when using just knots vs less wear and life extension on ropes when using hardware.
One more thing, due to the possibility of the rope jamming in the Figure 8 device because of too many rope overlaps, I plan tomorrow to cut 4 or 5 inchs off the top of the skinniest wooden handle I can find.... probably a broom and put the stick in the backside loop of rope where the winch hook connects. This will assure being able to just flip over the end of
the round metal eye and breaking all tension.

 

[pdqdl]

I dont think it possible on a 1/2 inch rope as I dont think any section of the Figure 8
is smaller than the rope so it couldnt be any different size wize than a knot in the rope. With a much fatter rope then I guess a small radius causing damage would be more likely.

I was using a 1/2 rope at the time I broke a rope on the rescue-8. That 2000lb log didn't even seem to slow down when it broke that rope. As I recall, I had it turned through the '8 two times for greater friction.

Just as a note: I've only broken two ropes in over 30 years of tree work. This occasion was when I was new to the rescue-8 and thought I would try it out as a friction device for lowering the log instead of using my big pulley made for the job. I was trying to shorten the distance of fall by using fewer rigging components.

I concluded that was a bad plan.

 

[preventec47]

This is how I was taught to lock off an 8, simpler and more secure. I think you will also find the right rope is going to make things a lot easier. That rope you have there honestly looks a lot like safety blue, and I'm sure you've noticed how much easier it is to work with.

It seems to me that this video depicts some necessare accomodation for the main purpose of rapelling down something and being able to lock and unlock. I think much of the design features/emphasizes
easy and quick variations in function and that is not needed for pulling down trees.

 

[TheJollyLogger]

It seems to me that this video depicts some necessare accomodation for the main purpose of rapelling down something and being able to lock and unlock. I think much of the design features
easy and quick variations in function and that is not needed for pulling

It seems to me that this video depicts some necessare accomodation for the main purpose of rapelling down something and being able to lock and unlock. I think much of the design features
easy and quick variations in function and that is not needed for pulling down trees.

Ok...

 

[TheJollyLogger]

I hate to say it, but you are reinventing the wheel again, this **** just isn't that hard, but you are way overcomplicating things.

 

[pdqdl]

Yup.

Besides, I've not seen the Alpine butterfly that cannot be undone with a hammer, vise, and a tapered punch. It'll come apart eventually. It seems to me I've had a few overhand or square knots that couldn't be made to let go. A really tight fisherman's knot just isn't going to be untied ever, unless you are on a caribiner that can be slid out of the choker.

 

[windblown]

This is purely an experiment of mine mostly motivated by the frustration two permanent alpine butterfly loops in my favorite long time 120 ft rope. I experimented with the same rope today
using the shackle and Figure 8 setups as photoed above but I only went to 1500 lb ie did not
add in mechanical advantage as I did not want to break my rope. when my new Stable Braid gets
here I will tension my new rope at 3000 lb with my pulley setup. My impression of the Shackle
is 100 percent positive as there is no way it can jam because the pins can be unscrewed. For the
Figure 8 it is prettier and lighter but it appears It would be easy to over do the rope over rope lock in mechanism as the rope tightens up and could result in the same thing as a jammed knot. I also tried another configuration of the Figure 8 as shown in the photos attached with even more rope over rope as tensioned to keep the rope from slipping. Tomorrow I hope to redo the tests and will take photos of the rope wrappings under great tension and see how I may need to redesign the load path through
the Figure 8 that will guarantee easy undoing. One minor annoyance is that the pin in the shackle will not slide through the hook on the More Power Puller winch because of the spring on the gate. The workaround is unscrewing the pin and sliding the pin through the middle of the hook as you reassemble the shackle. I do also plan to test the Artilleryman loop, the Bowlin on a bight, and the the Rosencinch knot as featured on Youtube. Regarding the possibility of the Figure 8 device
cutting a rope,... I dont think it possible on a 1/2 inch rope as I dont think any section of the Figure 8
is smaller than the rope so it couldnt be any different size wize than a knot in the rope. With a much fatter rope then I guess a small radius causing damage would be more likely.
Attached are two more configurations of Figure 8 showing how they were wrapped. There must
be dozens and dozens of differnt configurations and it could be possible to fine tune according
to the needs of each application. ie more or less round turns in more locations on the Figure 8 and overlapping or underlapping of the loops. The Wythe Puller at 3000lbs inclucing built in pulley
with another snatch block should produce 6000 pounds capability. I already have faith in the
shackles but I dont know about the 50KN Figure 8 device.at 6000 pounds.
It occurs to me there may be pros and cons of using hardware vs knots with the advantage of
not needing hardware when using just knots vs less wear and life extension on ropes when using hardware.
One more thing, due to the possibility of the rope jamming in the Figure 8 device because of too many rope overlaps, I plan tomorrow to cut 4 or 5 inchs off the top of the skinniest wooden handle I can find.... probably a broom and put the stick in the backside loop of rope where the winch hook connects. This will assure being able to just flip over the end of
the round metal eye and breaking all tension.

Well no one is going to say your reluctant to think outside the box! The only drawback to that versus relying on known proven methods and techniques is it tends to lead to unexpected and unwanted results, and going back to the drawing board repeatedly. I reckon as long as those results don't cause you or others harm it's just your new rope that's at risk.

Why put the new rope under a 3000lb load test? That's probably close to double the recommended working load limit. I'm not saying I don't exceed the working load on my ropes occasionally but I can't recalling ever doing it for kicks on a brand new rope I wanted to be able to depend on for a long time. Maybe the purpose of your desire to do so escapes me? If it's your homebrewed rigging you want to test why not test that with your old rope which is already compromised yet should still handle a 3000' pull unless it's completely trashed at this point.

I completely understand that your a bit peeved at having two alpine knots become permanent fixtures in your old favorite rope but as I think someone else mentioned, they aren't commonly used for BIG loads and the condition of your old rope may have played a part in them becoming jammed too tight to open back up. Just dn't throw the baby out with the bathwater. Alternative proven methods to attach the mainline rope to a pulling system will likely out perform getting creative on your own. That's not meant as an insult, it just that coming up with a better solution in a few days over what countless years of experimentation and development have come up with is just bad odds.

As an aside: The reason I stopped using midline knots in my "favorite" and expensive ropes when big loads are involved is that I REALLY hate turning a 150' rope into two shorter ropes. So yeah... been there and done that.

 

[pdqdl]

...

As an aside: The reason I stopped using midline knots in my "favorite" and expensive ropes when big loads are involved is that I REALLY hate turning a 150' rope into two shorter ropes. So yeah... been there and done that.

And on that line of thinking, something else occurred to me.

Whenever I put a big load on a rope tied to a tree, it is really, really important that it doesn't fail. If you are anywhere close to the load limit with your winch, then you should be doubling up your attachment with two ropes to two different strong points on the tree.
First, this will reduce the load on each rope and attachment points. At least in theory, you are spreading the load out on two ropes and two TIPs.
Second. If either attachment point fails, whether the rope breaks or the branch breaks off, you still have a chance of avoiding a really catastrophic failure.

I've done this a number of times when I use a big machine to pull over a leaning tree that is decaying and weak. So far, no catastrophes.

 

[preventec47]

I agree and concurr with everyones skepticism and after today's playing around I have my doubts about the Figure 8 and the reason I want to pursue it is because it is pretty and light. It has potential to be a tunable device with as much or as little grab as you want. On the other hand, I am totally gobsmacked with the function of the shackle.and an in-line loop connect. I enjoy learning about new knots and using them but at this point I cannot see any knot functioning as well as wraps around the shackle.
Strength, preservation of the rope, convenience, simplicity, speed eh maybe not faster than someone who can tie a knot in two seconds but less complicated than all the prussik contraptions. One more important thing... for me with the most horrible rope for tying knots.... pure nylon..... the shackle
gets the job done with no danger to the rope. I realize there are pros here who have done things for decades and dont feel the need to change.... Thats fine. But I have a new toy ( winch ) and gadgets
and a week at least to get my new rope so I have time to experiment, play with and get to know the winch and take photos etc. I am happy to share my experience as it happens and there might be something worthwhile and maybe not..... or just not needed. Either way,
it is the least I can do to pay back all the invaluable expertise that has been shared with me.
Once again, the shackles are $10 on Amazon ( two for 20 actually ) with shipping free. 3/4 inch
Real solid hunks of steel given to the world of arborists by the off road 4 wheeler crowd ... not sexy
but I would say bullet proof if anything ever was.

 

[pdqdl]

I have never used a shackle on a rope. Kindly share with us how you are making that attachment. Pictures would be nice, too!

And... nylon rope? I hope that's not 100% nylon. I might be mistaken, but I don't think any approved arborist ropes are made out of all-nylon. It has a low melting point, the knots are hell to untie (as you may have discovered), and it stretches too much. It is a well known fact that when a nylon rope breaks under excessive load (or what it is attached to breaks) then the end of the rope becomes a dangerous whip, and anything tied to the end becomes a missile.

...and you are mounting heavy shackles on the middle, in a likely breaking point. This isn't necessarily bad, but you might want to think about that a bit.

EDIT: I found an all nylon arborist rope. https://usarope.net/product/12-nylon-double-braid/
It wouldn't be my preference for a bull rope, but it might be fine for climbing on. Lots of shock absorbing stretch there, if you like your ropes stretchy.

 

[preventec47]

I have never used a shackle on a rope. Kindly share with us how you are making that attachment. Pictures would be nice, too!

And... nylon rope? I hope that's not 100% nylon. I might be mistaken, but I don't think any approved arborist ropes are made out of all-nylon. It has a low melting point, the knots are hell to untie (as you may have discovered), and it stretches too much. It is a well known fact that when a nylon rope breaks under excessive load (or what it is attached to breaks) then the end of the rope becomes a dangerous whip, and anything tied to the end becomes a missile.

...and you are mounting heavy shackles on the middle, in a likely breaking point. This isn't necessarily bad, but you might want to think about that a bit.

EDIT: I found an all nylon arborist rope. https://usarope.net/product/12-nylon-double-braid/
It wouldn't be my preference for a bull rope, but it might be fine for climbing on. Lots of shock absorbing stretch there, if you like your ropes stretchy.

PDQ, I agree on all points. Thats the reason why I have ordered a new rope for the 2nd time. The 1st time I mistakenly ordered Tenex TEC (based on technical specs) and had to send it back just a fe days ago. My old nylon rope is what I have used for pulling Trucks out of ditches and mud bogs for 15 years. I am only using it for testing and winch mechanical advantage practice on very small trees. Please reference the photos in the first message in this thread to see how I am hooking up with shackles. Like you said, my nylon rope ( probably Home Depot etc) is the worst possible for jamming knots. For all my towing and pulling in the past, I could only use multiple half hitches ( 5 or 6 with space between each one until the last one.) knots. to assure that I could untie the knots. I am gaining
confidence in my ability to now use plastic ground spikes as spacers in more complex knots
that can be removed after jamming to ease pressure in the knot and easily untie it. These spikes are
basically ten inch long nails of approx 3/8 diameter. BTW, I suffered the catastrophic consequence of a nylon rope breaking ( a large 1 inch dia ) when yanking a bush out of the ground with my pickup
truck.while getting a running start before the yank. I have learned that an effective preventative action for broken rope missles is placing old blankets etc on the stressed rope and if any odd pieces
of rope are laying around go ahead and connect loosely the stressed rope with any close by objects
or trees or even tying the other end to a spare log round to catch the missle if the rope breaks.

 

[pdqdl]

For all my towing and pulling in the past, I could only use multiple half hitches ( 5 or 6 with space between each one until the last one.) knots. to assure that I could untie the knots.

I use that myself when hooking to a truck. That is a knot listed in ABOK for just that purpose, but I forget the number.

I modify that a bit and put a taut-line hitch at the end of the tail. It keeps 'em from creeping together and making a compact knot that won't untie. If you find that your tail keep creeping down on you, put a half-hitch on on the loaded side of the rope, prior to securing the tail with your multiple half hitches. It won't creep then!

 

[pdqdl]

I never pull a bush with a rope. That's what chains are for. No stretch, more "yank".

Also, bump those bushes with many small hits, rather than one big one. The roots begin to tear, and each bump gets a few more. That way, the only thing you tear up is the bush you wished to extract.

 

[preventec47]

PDQ QUOTE: If you find that your tail keep creeping down on you, put a half-hitch on on the loaded side of the rope, prior to securing the tail with your multiple half hitches. It won't creep then!
--------------
Thats what I already do I think. The only place to tie the tail is to the loaded side of the rope. I take a big hank of the loop and tie the half dozen half hitches around the tensioned part of the pull rope.

 

[preventec47]

I have now pulled down eleven trees in my project and seven of them were leaning
in the wrong direction where I had to pull back past vertical to make sure of falling in
the right direction.... The largest tree so far was about 18 inch diameter at the base.
I am using the Wythe More Power Puller and 3/4" shackle for mid line connect between winch and the pull line. see pics attached. Here is shown
my 1/2" Stable Braid by Sampson at full tension using 2 to 1 mechanical advantage
pulley on the Wythe Puller. Full max tension being my full strength on the winch handle. ( the Wythe people advertise 3 ton lift and 6 ton drag capacity for the device but I really dont know how that translates into real world tension )
The shackle pics show the reduced diameter of the rope under tension (input) compared to loose. ( dangling end) I spent a lot of money ( for me ) for this rope and I intend to take good care of it and will try to minimize tying any knots in the rope so as to not introduce weak points in the rope.
It turns out that back up knots have not been needed with the shackles as the rope seems jammed pretty well in the shackle when tensioned, but it is very easy to unscrew the pin and the whole knot assembly falls right apart. It is possible to thread the rope loop through the hoop a second time ..... ie there is plenty of space in the hoop but there is sufficient grab with just one pass through the hoop.
Regarding backup knots in this application, if there ever was any slippage, the connection would only slide down the rope. Never could there be a chance of coming undone. One of the reasons I want to avoid the use of knots in my rope is I now realize a lot of guys are using much bigger ropes than this 1/2 inch rope to pull trees down with so I will likely exceed the working load limits of the rope since it is smaller and I dont want to weaken the rope unnecessarily by tying and untying knots in it.
The rigging of the shackle is simple and quick as there are not too many different ways you can thread a loop of rope into it before you attach metal hook to it.