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anyone know what knots to use on amsteel blue?

Grace Tree

Grace Tree

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Spliced eye. I think it's 12 strand class 2. Here's the Samson link:
Samson Splicing
I'd follow the splicing instructions exactly; specifically the lock. It's easy stuff to splice but it's slippery stuff. I spliced an eye wrong and after using it for a couple months it slipped the splice. It was just a leftover scrap that I used for a pull handle but it did make me more careful. I made a few 3/8" slings and have used them for a couple years with no problems.
Phil
 
pdqdl

pdqdl

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You can talk about splicing until you are blue in the face; sometimes you need a knot. Like when you are 30' from your stuck tractor, your amsteel is 150' long, and that would put you in the mud on the other side of the road.

Knots in amsteel tend to choke down and squeeze the knot in half, or so I've been told. DON'T try a bowline on a heavy load. I'm only repeating stories, as I have never managed to hurt my 150' amsteel rope

If you are rigging a rope to something like a truck you might try this, it worked well for me a couple of times. It's guaranteed to come apart when you need to untie it, and I suspect that it is as strong as any other knot. Anthony Book of Knots lists it as the right knot to attach a rope to a vehicle for severe loading. Sadly, I can't find my ABOK, and I don't remember the name.

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The load would be applied to the single line hanging down to the floor, and the lowest half-hitch takes the majority of the load. I always stretch the knot out real good by hand before I step on the gas. So far, it has never failed me, but I don't use it that often. I tied this in some old arborplex, because I didn't want to hike out and get my amsteel.

This knot is really nothing more than passing the rope around some structure like the tow ball on your truck, then pulling a nice long loop through a marl or "half-hitch". Do it a few more times, and then stretch it out. Step on the gas!

That first half hitch will be choking down awful tight though...I'd test it's strength a little before you over load it on something critical.

If tying to a tree: Timberhitch holding a marl is almost infallible. It never slips and it never binds down.

I would avoid mid-line knots entirely.
 
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moray

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Knots in amsteel tend to choke down and squeeze the knot in half...

I believe this is a general property of hollow braids. I have tested Tenex knots to failure and even the best knots failed below 50% of nominal rope strength, and some failed as low as 30%. The same knots in a double braid did far better.

An Amsteel-Blue girth hitch that I tested to failure failed more or less as pdqdl describes--the "bridge" of the hitch squeezed so hard on the highly-tensioned legs of the hitch that it cut them in two!

If you absolutely have to tie a knot in a hollow braid, derate the rope to 30% of nominal. For Amsteel, I would go lower still.
 
lone wolf

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I believe this is a general property of hollow braids. I have tested Tenex knots to failure and even the best knots failed below 50% of nominal rope strength, and some failed as low as 30%. The same knots in a double braid did far better.

An Amsteel-Blue girth hitch that I tested to failure failed more or less as pdqdl describes--the "bridge" of the hitch squeezed so hard on the highly-tensioned legs of the hitch that it cut them in two!

If you absolutely have to tie a knot in a hollow braid, derate the rope to 30% of nominal. For Amsteel, I would go lower still.

sounds like i better get an eye spliced huh?
 
pdqdl

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What are you doing with it? Making slings, using it as bull rope, winch line, or what...?

I use my 3/8 amsteel rope as a tow rope for machines stuck where there is poor access for anything closer, or as an extension for the winch line on my little crane/chipper truck. It doubles nicely for a light duty speedline too, because it is so light and easy to handle.

I don't recommend it for any application that uses a lot of friction, like natural crotch rigging, or heavy speedlines without pulleys to slide down the rope. It melts very easily.

I tried climbing a tree DbRT with it once: it was terrible. Impossibly slick, the friction knot was not holding well. Furthermore, just my puny 230lbs and the associated friction was causing some fraying on the rope. I never did that again.

When using it on a shorter tow that cannot use all 150', I either double it, or tie it off using the knot I showed above.
 
tree md

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I believe this is a general property of hollow braids. I have tested Tenex knots to failure and even the best knots failed below 50% of nominal rope strength, and some failed as low as 30%. The same knots in a double braid did far better.

An Amsteel-Blue girth hitch that I tested to failure failed more or less as pdqdl describes--the "bridge" of the hitch squeezed so hard on the highly-tensioned legs of the hitch that it cut them in two!

If you absolutely have to tie a knot in a hollow braid, derate the rope to 30% of nominal. For Amsteel, I would go lower still.

Sorry to get off topic but I would be interested to know if the timber hitch and cow hitch failed at below 50% on the Tenex Moray. I had a timber hitch fail on my Tenex sling onetime is why I ask. I mostly use double braid now but still use the Tenex sling occasionally. That will become even less if it is going to fail at 50%.
 
pdqdl

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I always follow Moray's splicing stuff pretty closely. He does good work. I suspect that his setup does not really allow for load testing either cow hitch or timber hitch, since he uses hydraulics to pull between two fixed points.

Load testing a timber hitch would mean either setting up hydraulics to push away from a fixed point (very difficult to control) or that he would have to mount a spar of some sort in the middle of his setup. When the rope broke, he would be confronted with how to stop the parts from flying that were still attached to the tensioned rope.

Essentially, he would have built a hydraulically powered slingshot if he mounted a log in the middle of his setup. That test would probably be pretty dangerous.
 
lone wolf

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Sorry to get off topic but I would be interested to know if the timber hitch and cow hitch failed at below 50% on the Tenex Moray. I had a timber hitch fail on my Tenex sling onetime is why I ask. I mostly use double braid now but still use the Tenex sling occasionally. That will become even less if it is going to fail at 50%.

did you back it up with a half hitch?
 
lone wolf

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What are you doing with it? Making slings, using it as bull rope, winch line, or what...?

I use my 3/8 amsteel rope as a tow rope for machines stuck where there is poor access for anything closer, or as an extension for the winch line on my little crane/chipper truck. It doubles nicely for a light duty speedline too, because it is so light and easy to handle.

I don't recommend it for any application that uses a lot of friction, like natural crotch rigging, or heavy speedlines without pulleys to slide down the rope. It melts very easily.

I tried climbing a tree DbRT with it once: it was terrible. Impossibly slick, the friction knot was not holding well. Furthermore, just my puny 230lbs and the associated friction was causing some fraying on the rope. I never did that again.

When using it on a shorter tow that cannot use all 150', I either double it, or tie it off using the knot I showed above.
chipper winch.
 
tree md

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did you back it up with a half hitch?

Yes I did but to be fair I was using it as a redirect and pulling a stump over with a truck when it failed. I had the block pulled out 90 degrees from the tree so it was not being pulled straight up and down when it failed. Plus, I could have set it in a better spot on the tree.

I had a large stump, about 4' tall and 60" that I had missed the cut on towards the center. After trying to pound wedges into the kerf and having two men try to rock it and break it over I decided to put my block on a nearby tree for a redirect and pull it over with the truck. I tied a timber hitch and backed it up with a half hitch. When I tried to pull it over with the truck the timber hitch came out of the Tenex sling.
 
moray

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Sorry to get off topic but I would be interested to know if the timber hitch and cow hitch failed at below 50% on the Tenex Moray. I had a timber hitch fail on my Tenex sling onetime is why I ask. I mostly use double braid now but still use the Tenex sling occasionally. That will become even less if it is going to fail at 50%.

No, I haven't tested either of those, pretty much for the reasons so colorfully laid out by pdqdl. I really do have to worry about big things flying.

That 50% figure represents a knotted eye experiencing a straight pull. Could you not splice up a whoopie or loopie sling? That would be the best use for Tenex and should give great performance. I really don't think Tenex was designed to be used in the same way as solid ropes, though with sufficient derating it should be OK.
 
tree md

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No, I haven't tested either of those, pretty much for the reasons so colorfully laid out by pdqdl. I really do have to worry about big things flying.

That 50% figure represents a knotted eye experiencing a straight pull. Could you not splice up a whoopie or loopie sling? That would be the best use for Tenex and should give great performance. I really don't think Tenex was designed to be used in the same way as solid ropes, though with sufficient derating it should be OK.

Yes, Tenex loopie sling is what I was referring to. All of my heavy rigging is done with double braid bull line.
 
tree md

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I have been using 3/4 Tenex loopie sling for about 4 years now. I think it's a 12' sling, can't remember. In all honesty, it has worked pretty well for me. I have blocked wood up to 28-30 inches with it. As big as I can safety get it around. Never had a problem with it failing or the knot coming out as long as I was using it like I was supposed to, blocking wood with the block hanging straight up and down on the tree. Pulling the knot out with the truck did give me pause though. I have been using a double braid sling that I have because it seems to hold knots better and absorbs shock better as well.

I have to block some serious wood here in the next few days (36" pieces of Oak). I was going to use the Tenex sling as I feel that it would handle wood that size as long as it's set properly but the sling is too short to go around the tree and tie a safe hitch. I was just going to use my 3/4 bull line but went ahead and ordered an 18' double braid eye sling to do the job since the weather bought me some time on it. Tenex works OK but I like the way Double braid stretches a little to absorb shock plus it holds arborist knots great.
 
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moray

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...I have been using a double braid sling that I have because it seems to hold knots better and absorbs shock better as well.

...I was going to use the Tenex sling as I feel that it would handle wood that size as long as it's set properly but the sling is too short to go around the tree and tie a safe hitch...

I am confused. What are these knots and hitches you are tying with a loopie sling?
 
tree md

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I am confused. What are these knots and hitches you are tying with a loopie sling?

I'm actually the one that was confused. I am using an eye sling, not an adjustable loopie sling. It's just a regular eye sling that I use with a cow hitch, preferably, to attach my block when I have enough line to tie it. When I don't I use a timber hitch.
 
pdqdl

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Sorry, been away from the thread a while. To return to an earlier theme:

I think the tenex is more likely to fail than an equal strength double braid in a shock loading because the tenex has less elasticity. Given a knot or other sharp bend, the outer fibers will even shear sooner on a slow pull, given the reduced ability to stretch.

There is an interesting video on YouTube that shows an elastic rope holding a shock load (repeatedly) and an Amsteel rope failing the same test on the first run, despite being a much stronger rope.

Lone wolf: that amsteel is perfect for the winch line, but put some splices on it. You are very unlikely to ever shock load that winch very much, anyway.
 
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