Load sharing SRT TIP for double stem

LordFarkwad

Well-Known Member
Was climbing on a canopy anchor in a pine next to the house, having a single stem that splits at about 50' up or so. I advanced my canopy anchor until I was at the split, then simply continued to advance it upwards, encompassing both stems. I am not crazy about the theoretical amount of stress that cinching loop places laterally on each stem.

Is there a simple arrangement that allows my weight to be distributed between both stems, but doesn't place a large lateral force on each of them?

I'm imagining something like a "Y", where the upper two legs are each joined to the two stems, and I am hanging from a point in the center, between the two legs.

Is there any way way to do this, or something entirely different that distributes my weight between the two stems without the lateral forces produced by a cinch encompassing both stems?

Photo attached is of the tree and my anchor prior to advancing beyond the split.

Any and all commentary is welcome.

IMG_20190701_174636608_resize_86.jpg

IMG_20190701_174636608_resize_86.jpg
 

rope-a-dope

Well-Known Member
You could pass your rope around both stems, tie a butterfly where you want the angles to meet and clip the splice, knot, and span of rope between the leads with one biner. One time I finished a tree for a buddy on his rope while he repaired the mini. He had tied 2 clove hitches to both stems and clipped the rope below to the splice. Maybe there was another knot...
 

Bango Skank

Well-Known Member
Maybe your choked line on one stem, then a choked loop runner on the other stem. Clip a biner on the loop runner and clip the biner through a clove hitch or AB or something that’ll stay put below your choked line? As you said, a “ Y” .

I don’t see anything too catastrophic happening from continuing to choke both stems though, besides it being a pain in the ass to advance.

Furthermore, I’d probably say screw all that and just continue on the dominant stem only, the one on the left in your pic. Depending what you’re doing I guess. What are you doing, rec climbing?
 

LordFarkwad

Well-Known Member
What are you doing, rec climbing?
Yeah, just practicing in the yard. This was one of the first times I'd ever set a canopy welcome from the ground. So easy to advance! The availability of limbs really sucked, up to that split at least, so it was a real learning experience setting the anchor and also advancing it without being able to ladder up using double lanyard or lanyard and climb line.

To that end (advancing), I actually ended up doing it painfully slowly, by alternating ascending SRT (foot ascender) between the lanyard and climb line. I'd just advance either upwards along the spar as high as I could reach, then move up along that one using the foot ascender. Then I'd advance the other upwards as far as I could reach, and continue alternating. It was slow, but that's all I could think of how to do.

dominant stem only, the one on the left in your pic.
Are you judging based on the size of it? I want sure how to tell, and that union looked sketchy, at least to me. Is that union indeed not as good as it could be?

Maybe your choked line on one stem, then a choked loop runner on the other stem. Clip a biner on the loop runner and clip the biner through a clove hitch or AB or something that’ll stay put below your choked line? As you said, a “ Y” .
Is there a way to use a Pinto (or other life support rated pulley) to act as a load-distributing element in a similar arrangement? In other words, to ride the 'sag' between the two supporting legs of the "Y" so that the weight equalizes between the two leads?
 

LordFarkwad

Well-Known Member
You could pass your rope around both stems, tie a butterfly where you want the angles to meet and clip the splice, knot, and span of rope between the leads with one biner. One time I finished a tree for a buddy on his rope while he repaired the mini. He had tied 2 clove hitches to both stems and clipped the rope below to the splice. Maybe there was another knot...
Painful to advance, or not?
 

swingdude

De' Island Buzzer
Was climbing on a canopy anchor in a pine next to the house, having a single stem that splits at about 50' up or so. I advanced my canopy anchor until I was at the split, then simply continued to advance it upwards, encompassing both stems. I am not crazy about the theoretical amount of stress that cinching loop places laterally on each stem.

Is there a simple arrangement that allows my weight to be distributed between both stems, but doesn't place a large lateral force on each of them?

I'm imagining something like a "Y", where the upper two legs are each joined to the two stems, and I am hanging from a point in the center, between the two legs.

Is there any way way to do this, or something entirely different that distributes my weight between the two stems without the lateral forces produced by a cinch encompassing both stems?

Photo attached is of the tree and my anchor prior to advancing beyond the split.

Any and all commentary is welcome.

View attachment 60799

View attachment 60799
Bro just head up and canopy on the left side you good....
 

RBJtree

Well-Known Member
Why are you worried about lateral forces on those stems? You will never break them with your body weight by pulling them together. If it is just an exercise in how to rig yourself to reduce the lateral load for the sake of learning, cool. If I was climbing it I would probably use a mrs system to advance on the larger lead and balance myself when needed by throwing my lanyard around the other lead. Assuming there was some reason to not just set an srt line near the top with a throw ball. Honestly, I very rarely do any top half pruning in conifers so 99% on the time if I am in the top half its on spikes and the tree is coming down.
 

LordFarkwad

Well-Known Member
If it is just an exercise in how to rig yourself to reduce the lateral load for the sake of learning, cool
That is it. I'm not necessarily saying I think it'll break out (of course, I don't have enough experience to really have a comfort level at this point with stuff like that). But, I can conceive of a situation in the future in which I might need to have a tool like I'm describing in my toolbox. Better to learn it now and get comfortable with it, than to defer it until I'm in that situation and might need it.

Bro just head up and canopy on the left side you good....
I trust you guys' judgement on whether or not that's solid. See above for additional explanation.

Can y'all give me some free lessons on the union itself? It looks like included bark. Isn't that a stress riser? There's 5" of good wood there (on the right, and more like 7"-8" on the left), so no worries of it breaking, right?
 
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RBJtree

Well-Known Member
Judging by the picture, I wouldn't be worried about breaking at that area. I would stay towards the larger side if I went much higher. Yes there is some included bark, that is one reason I would stay on the larger side. I won't say its definitly safe from a picture though. Anything could happen. I don't want to be responsible if it breaks.
 

Treezybreez

Well-Known Member
Great tread topic! Sometimes its worth the extra peace of mind to have a TIP on both leads. the ability to safely tie in just a little higher might be exactly what you need.

I usually tie a scaffold knot or an alpine butterfly to a biner, cinch it to one stem, put a bite around the other and clip it with a biner.

If I'm wanting to rig a little higher up on a co-dominate stem, then I will either strap the stems together, or attach a block to each stem. If the stems are too close together the blocks will slam into each other and can cause damage.
 

swingdude

De' Island Buzzer
That is it. I'm not necessarily saying I think it'll break out (of course, I don't have enough experience to really have a comfort level at this point with stuff like that). But, I can conceive of a situation in the future in which I might need to have a tool like I'm describing in my toolbox. Better to learn it now and get comfortable with it, than to defer it until I'm in that situation and might need it.



I trust you guys' judgement on whether or not that's solid. See above for additional explanation.

Can y'all give me some free lessons on the union itself? It looks like included bark. Isn't that a stress riser? There's 5" of good wood there (on the right, and more like 7"-8" on the left), so no worries of it breaking, right?
I have climbed high into previously topped trees. You just have to inspect well. Saying that do not go higher if your senses tell you otherwise....please.
 

Jan_

Active Member
Just wanted to say that the maximum theoretical force pulling the stems together is 4x your weight, but only if you ignore the substantial friction and assume you are climbing at the worst angle to the TIP and create a 2:1 MA. All of this wont happen though, so there should really not be much force there at all.
 
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