Is this a safe/legitimate rigging method?

[treesmith]

Kenny's posts sound like Spock.....all knowledge...no emotion....

 

[murphy4trees]

There's gold in them there hills

 

[rfwoody]

Why not just tie a bowline in the end that you're clipping the carabiner to and cow hitch or timber hitch the tail?

Good question.... but my goal is to get as much strength as possible out of the 1/2 3-strand rope.
The Bowline reduces strength to 60% of original.
And I believe the WWL (1/5 breaking strength) is 1000#
So I figured by using 3 (e.g.) wraps or so, I could make a relatively strong(er) poor man's sling

I'd make a rope sling. Nice length of rope ends tied in a zeppelin knot and you have a versatile loop.

That sounds like a great idea for the sling part... but I would still be limited by the strength of a single strand of rope, right?

Forget the nylon sling. If you have enough 1/2" line to go around the tree 4 times, just use it doubled. Find the middle and clip that to the carabiner, then use the doubled line to make a timber hitch onto the tree.

Yes, I found the nylon sling was unnecessary. I just clipped the carabiner directly to the rope.

Looks ok. I bought a 30 ft piece of 3/4 tenex to go around the base of trees too large for my slings. I tie a bowline and it will hold anything I need. As DMC said just tie a loop in a piece of 1/2" and loop it around the tree. That's a 7,000 lb line doubled. Should be more that you'll ever need.

I believe I heard somewhere that the timber hitch doesn't like to be loaded in one certain direction. Can't remember which. Either straight out or back towards the loop. I think Patrick had a video about it on Educatedclimber. But I've never had it come loose on me.

It is good to hear that others are using just rope and a Bowline to replace an adjustable sling.
Part of my goal though is to get max strength from the 1/2" 3 strand rope.

If you can't tie a bowline, you should find a new line of work.

ha, a plain old bowline I can tie... the running bowline is what I haven't mastered yet.

Knot/seam should be buried thru wraps from hit of impacts and loading.
>>So, any knot that holds should be okay, and easy to untie since not getting jammed with forces.
>>this would be true of knot 'seam' for holding hitch to tree/anchor and for making eyes as well, keep seams from primary loading zones.
>>work to not expose/risk seams to primary/full forces
So bury seam from forces, and focus on grooming parts taking hit
.
Clock is WRONG, not just a little bit; REAL WRONG
"They should call it the Clockwork Orange Hitch.. it's criminal to use that thing." -JeffGu/TB
.
Same principle elements, slightly stronger flavour/strength fave type setup amongst mountain/rescue:

.
In your pic and Clock: pulley pulls across rope column(s)
>>want teepee to pull out from trunk, the farther the better for sharper point showing straighter pulley pull down rope column/length properly.
.
i threw math not to confuse but to show what is proper/why
>>then also how 'out of line' clock and your pic are with how those numbers work
AND they go across ALL examples, there is no escape, only blind bumping into if can't see...
.
The wrap 2 pull 1 pic isn't that much different than yours or Clock
>>some turns and a protected seam from the direct hit
NOTE: biggest strength is at rope parts taking hit, flat to tree is wrong for this, real difference is the 'point' that serves out to pulley in wrap 2 pull 1
Big Difference is how most loaded , immediate loading of pulley pulls on the support legs directly to it
>>In Clock and your pic, this pull is PERPENDICULAR to the rope parts directly supporting against pulley
This leverages/wrenches against line strength
>>can you hold 20# inline at side or perpendicular straight out from chest longer????
>>which way is your own feels like architecture stronger?
>>if can get to where use such an imagery, and can look at rope and see that would be pull on arm, i say knowledge becomes more intuitive body sense; which also can give most immediate correct action in emergency...
Relax perpendicular pulls to birds beak / teepee point, that immediate pulls can go down more than across these strands/columns
>>would IMMEDIATELY make your pic and Clock better, then maintain buried seam away from hit/loadings
>>the flatter the teepee, the weaker the rope is, the Clock and your pic is FLAT >>can't get any worse ('cept maybe if pulling tight to flat beam rather than round spar) !!
>>longer and longer sharp point teepee is closer and closer to being a most proper eye
Flat vs. Eye are the 2 benchmark range extremes, that all the rest are between
>>Clock and your pic are at the wrong extreme end of that range pulling perpendicular across supports rather than INLINE
Strength being chased hear is 100% geometry, once have seam as weak link buffered from hits
.
We say making doubled rope/eye gives about double strength in ruff math
>>but there are numbers out there that assume some loss and quote at at like 165%(KnudeKnoggin big advocate i believe, perhaps the SMARTEST rope/knot mind i've ever come across; that i have learned the most from) instead or 200% rope tensile
>>Much worse if rope is stiff and resists in any way eye bend
If making own eye sling for like Cow or Timber, would make long eye so only eye takes hit and the knot seam making eye is buried on tree so seam doesn't take primary hit. Personally i'd use Double Bowline w/Yosemite tie Off (affectionately known as DBY) on the long eye, making sure knot doesn't take hit, it is on the tree, maybe even rope strands crossing OVER eye too before seam/DBY receives hits.
.
Extending that buffering loading to seam topic further AND ALSO add strength to Timber or Cow i prefer Round Turn around Standing Part/eye to pulley rather than simple Turn before commencing with rest of Cow or Timber.
.
edit: in the word 'architecture' arch means not flat bridge etc. construction but rather they found arc to keystones to route force around flat construction(but still give flat service on top side to bridge etc.)
>> cosine of inline is 1, i read as 100% strength, less inline is lower cosine /less preserved strength percentage.
>>all the way down to flat is Zer0 cosine.
0-1 range multiplier of rated strength to find actual is all cosine is, from PURE INLINE(1) TO flat (0)
once again; Clock and your pic are on the low end of the preserved line tensile scale, hardly any cosine left.
This rope example is just a microcosm of the same rules of how ALL this works!

Kenny/TreeSpyder, .... will you please let me know if I am understanding correctly:

* The "beak" configuration is what is desirable/stronger vs. the "flat" configuration (like my pic and the clock hitch).
* The reason the beak is stronger is because it is loaded closer to pure inline (even with a 60 deg. "beak") which is closer to cosine of 1 which means 100% strength.
* The reason the flat (my pic and the clock hitch) is weaker is because it is loaded closer to cosine of 0 which is as weak as you can get.
* If using a knotted loop, the knot should be in front, "In the span between spread lines on front/pulley side of anchor support is best place for seams, as most buffered from loadings and visually inspectable."
* Doubling (tripling/quadrupaling) rope strands parallel (e.g. my example and the clock hitch) does NOT multiply the strength of the rope by the number of rope doublings as one might intuitively expect.

*** The take-away/recommendation from this... short of using a real sling... appears to be to do something like Benjo did.... buy a heavy duty rope and tie a bowline (or DBY) in it.

Do I understand correctly?

Thanks!

P.S. will plan to review your post here about splicing... but right now my brain is starting to overheat, i think.

Great info, as always.


3 strand end to end splice is easy to do. Make a sweet sling!

Raj, you motivated me to go ahead and learn how to splice 3 strand rope... I did one (found a couple of good videos on youtube) and plan to do more for some/more/most of my 3 strand rigging rope.

NOTE: I recently used my original concept before carefully reading and trying to digest Kenny/TreeSpyder's post (I used the "clock hitch" configuration).
Planning on posting pictures of that job and hoping for any and all comments/criticism/laughter that any and all might care to give.

Thanks again All!