Single or double wrap for basal anchor?

JMB6

Member
Location
Cary
I know everyone is wrapping just once for basal anchor. However, it looks to me that if I wrap it twice there is no chance that the anchor rope will ever slip.
Anyone here uses double wrap for basal anchor?
Thanks.
 

Dan Cobb

Well-Known Member
Location
Hoover
I frequently double wrap, but I was involved with technical rescue long before tree climbing so I tend to be conservative with rigging. It's hard to escape your past.
 

Brando CalPankian

Active Member
Location
Washington
Depends on the tree. For the most part no. I like the idea others have mentioned about a partial wrap as the rope is coming down the trunk. I rarely ever have concerns about the rope slipping. I only climb on base tie to ascend too, so I'm only on it for a matter for 30 seconds or so. My 2©.

Climb high!
 

Brando CalPankian

Active Member
Location
Washington
Oh! I'd say early on my biggest concern was with a single bowline coming undone, as now and then they can work themselves free. I prefer alpine butterfly now. The base tie cinches pretty hard once it's weighted, if dressed and set nicely.
 

evo

Well-Known Member
Location
My Island, WA
Sometimes I will take as many wraps as I can, the more friction on the base anchor (near the tip) seems to drastically reduce forces on some type of trees (conifers). Also when the odd limb snaps it’s more likely for your line to fall tight in the whorl below v sliding outward from the crown (western red cedar).
I use to do it and then base tie with a bowline. Since then I now just base tie with a backed up running bowline, and place a alpine butterfly a few feet up the line (add a rescue loop).
 

Brando CalPankian

Active Member
Location
Washington
Me
Sometimes I will take as many wraps as I can, the more friction on the base anchor (near the tip) seems to drastically reduce forces on some type of trees (conifers). Also when the odd limb snaps it’s more likely for your line to fall tight in the whorl below v sliding outward from the crown (western red cedar).
I use to do it and then base tie with a bowline. Since then I now just base tie with a backed up running bowline, and place a alpine butterfly a few feet up the line (add a rescue loop).
Me likey
 

TheTreeSpyder

Well-Known Member
Location
Florida>>> USA
i think there is a whole science to making at least 3x180 arcs (Round Turn) to allow more of a 2 dimensional grip on host in my mental imagery. On a scale of kinda workable to mechanically positive shrinking eye around trunk to up and over a branch redirect to load is not to high end of scale.
.
The 2D structure from centers of each 180 compressing INTO the tree(as all or rest of rope forces trace AROUND tree) does not exist until 3x180arcs and more arcs, then expands on the ideal if add more 180s.
.
This angle of pull up trunk is what ABoK references in exclusive topic on 'lengthwise' pulls as the worst angle to pull any knot, and the "impossible not to be expected" (opening pre-ramble of chapter_22). Right angle to host is the most proper angle of pull, lengthwise pulls are literally a different dimension.. If pulled a Running Bowline at this angle dragging a log, can be like dragging a wild cat flipping around, preceding tho with Half Hitch can calm this beast to drag politely as does throwing Half before Timber for lengthwise pull to make Killick.
.
Placing simple 1x180arc Running Bowline basal works some because of the buffer of the redirect turn at peak/would be TIP between load and hold. But, i still think is most mechanically proper to upgrade to 2D grip potential of 3 or more 180arcs, and the top redirect/buffer just extra frosting, not main.
.
Force-dimensions-4of4-multi-dimensional-load-needs-multi-dimesnion-support-from-rope-etc.png
A pre-fixxing with a Half Hitch allows the formation. This allows the standard right angle pull on host and then also the 2D form to extrude pulling away from rope structure or MAY conspire to self crossing hitch as like rope version of can't lift self by own bootstraps trap. The extra geometry of the more arcs allow forces to self moderate to get wider usage range.
.
Though a 180 Turn redirect to load leg buffers force timing to Timber/Running Bowline/simple shrinking eye; I would not favor trusting whatever force passed indirectly that would not trust whatever directly passed to same support geometry, and then only with care, especially in life risk situations, especially on even miniscule receding taper. Varying bark slickness also a player here; to such a global offer.
 
Maybe see also:
It's at about 1:06:00 in the video with Richard Hattier and Nick Bonner
 

Stumpsprouts

Well-Known Member
Location
Asheville
I just learned a trick from a fellow climber, this is so simple but really helps a running bowline cinch on a trunk. Instead of wrapping the end of the rope around the working end once, you wrap it around twice. Once it comes under load, it really holds the knot well.

Others I work with start their basal anchor with a half hitch before the running bowline.

I will be using the first method from now on, it’s a little bit easier and requires less rope.
 

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Brando CalPankian

Active Member
Location
Washington
I just learned a trick from a fellow climber, this is so simple but really helps a running bowline cinch on a trunk. Instead of wrapping the end of the rope around the working end once, you wrap it around twice. Once it comes under load, it really holds the knot well.

Others I work with start their basal anchor with a half hitch before the running bowline.

I will be using the first method from now on, it’s a little bit easier and requires less rope.
I dig that. I'm going to try that this week. Thank you for sharing!
 

Brando CalPankian

Active Member
Location
Washington
i think there is a whole science to making at least 3x180 arcs (Round Turn) to allow more of a 2 dimensional grip on host in my mental imagery. On a scale of kinda workable to mechanically positive shrinking eye around trunk to up and over a branch redirect to load is not to high end of scale.
.
The 2D structure from centers of each 180 compressing INTO the tree(as all or rest of rope forces trace AROUND tree) does not exist until 3x180arcs and more arcs, then expands on the ideal if add more 180s.
.
This angle of pull up trunk is what ABoK references in exclusive topic on 'lengthwise' pulls as the worst angle to pull any knot, and the "impossible not to be expected" (opening pre-ramble of chapter_22). Right angle to host is the most proper angle of pull, lengthwise pulls are literally a different dimension.. If pulled a Running Bowline at this angle dragging a log, can be like dragging a wild cat flipping around, preceding tho with Half Hitch can calm this beast to drag politely as does throwing Half before Timber for lengthwise pull to make Killick.
.
Placing simple 1x180arc Running Bowline basal works some because of the buffer of the redirect turn at peak/would be TIP between load and hold. But, i still think is most mechanically proper to upgrade to 2D grip potential of 3 or more 180arcs, and the top redirect/buffer just extra frosting, not main.
.
Force-dimensions-4of4-multi-dimensional-load-needs-multi-dimesnion-support-from-rope-etc.png
A pre-fixxing with a Half Hitch allows the formation. This allows the standard right angle pull on host and then also the 2D form to extrude pulling away from rope structure or MAY conspire to self crossing hitch as like rope version of can't lift self by own bootstraps trap. The extra geometry of the more arcs allow forces to self moderate to get wider usage range.
.
Though a 180 Turn redirect to load leg buffers force timing to Timber/Running Bowline/simple shrinking eye; I would not favor trusting whatever force passed indirectly that would not trust whatever directly passed to same support geometry, and then only with care, especially in life risk situations, especially on even miniscule receding taper. Varying bark slickness also a player here; to such a global offer.
This is a great explanation. It makes sense, that's why we throw half hitches into the mix when rigging. Extra squeeze and changes the knot angle a bit. Does it reduce the knot strength when utilizing a standard bowline with no wraps?

Also, as someone in a pre engineering degree path, are there any books/resources you'd recommend on the topic?

Thank you!!!
 

TheTreeSpyder

Well-Known Member
Location
Florida>>> USA
i present the sense i've personally made of all the permutations have witnessed and distilled as consistent patterns in ABoK etc. Forming theoretical pattern relationships and testing all possible against them, to these distilled common points. Mostly all in own head, to own lingo, stolen from many places, over many years condensed to unravel now.
.
ABoK chapter_22 for specialty of lengthwise pulls lend on primary loading pull/ imposed input to majorly some type of Half Hitch(HH) pre-fixxing , especially on single leg of pull, few self crossing and finally for some dual leg pulls kinda Tresse friction hitch of opposing slanted legs (30° many times) that are pressing towards each other around host .
.
Strength/knot efficiency usually calc at most loaded part (Standing Part/SPart) and how harshly deformed from pure inline. HH of pass thru form /pre-fixer is low efficiency, or even as HH termination/1 end pulled form. HH prefix/pass thru/both ends pulled stronger tho if set to more proper right angle pull where can witness SPart taking less deformity with primary arc around fair sized host, then HH pre-fix lengthwise pull away from self where cranks/distorts harsher around self.
.
Tighter cranked to host Bowline etc. to SPart at a cost to strength/efficiency. Tighter cranks to grip host across SPart , more harshly deforms SPart/primary loading in reciprocal payoffs .
 
Last edited:

moss

Well-Known Member
When I'm basal anchoring on "normal" circumference trees I like the single wrap a little loose before I load it up. That way when it is loaded whether mechanical or rope-on-rope (backed Running Bowline) the angle of the standing end of the line is nice and open going up through the Bowline or mechanical (quick link or Quickie). For a slippery bark species like beech, black birch or bald cypress, to name a few, the first wrap tight the second is the "loose" wrap to keep angles rope friendly.

I think the misconception here is that climbers are concerned that if they slack the line while in the tree and then reload bad things can happen. Well... they can but a climber should never just jump on their system after slacking, always tighten up then load the system before continuing. I think most climbers do that but it's good to mention from time-to-time. It actually doesn't matter if your basal anchor slides up a few inches or a couple feet during a slack/reload cycle if you do the tighten up before continuing, it takes about four seconds.


-AJ
 

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