Questionable line set/TIP

[tree md]

Ever set a line for an anchor or TIP and had a bad feeling about it? I had this happen to me last week while I was trying to test out a new saddle. I set a line in a large hardwood that has extensive storm damage. There is a lot of brushy regrowth from where the tree lost most of it's crown. I shot my line into a high fork and then shot the other end of my throw line under the fork to isolate the limb. I put my full weight on the line while on the ground to try to get it to seat in the fork. It broke a couple of limbs out and I couldn't tell if it was seated properly. I was going to footlock up the line but had a bad feeling about it as I couldn't really see how well the line was set. I decided to just gaff up the tree (which is slated for removal) and stay tied in with a lanyard until I could check the line out and set a friction saver and make sure it was seated properly. When I got up to the TIP I could see where it had broke a semi large hanger, which had sprouted new growth despite being split, out and my line was hanging from a small branch maybe an inch thick. I don't know what happened but the line should have been isolated around a good limb in the fork. As it were, it looked as if I had shot both ends of the line through the same fork, even though I saw one go over and one go under. Anyway, I'm glad I went with my gut on that one and decided not to ascend on the rope. It can be very challenging to set a line in these storm damaged trees. I have often reverted to setting my line in a lower "for sure" crotch then advancing it once I get to the set TIP.

 

[BlackenedTimber]

Ever set a line in for an anchor or TIP and had a bad feeling about it? I had this happen to me last week while I was trying to test out a new saddle. I set a line in a large hardwood that has extensive storm damage. There is a lot of brushy regrowth from where the tree lost most of it's crown. I shot my line into a high fork and then shot the other end of my throw line under the fork to isolate the limb. I put my full weight on the line while on the ground to try to get it to seat in the fork. It broke a couple of limbs out and I couldn't tell if it was seated properly. I was going to footlock up the line but had a bad feeling about it as I couldn't really see how well the line was set. I decided to just gaff up the tree (which is slated for removal) and stay tied in with a lanyard until I could check the line out and set a friction saver and make sure it was seated properly. When I got up to the TIP I could see where it had broke a semi large hanger, which had sprouted new growth despite being split, out and my line was hanging from a small branch maybe an inch thick. I don't know what happened but the line should have been isolated around a good limb in the fork. As it were, it looked as if I had shot both ends of the line through the same fork, even though I saw one go over and one go under. Anyway, I'm glad I went with my gut on that one and decided not to ascend on the rope. It can be very challenging to set a line in these storm damaged trees. I have often reverted to setting my line in a lower "for sure" crotch then advancing it once I get to the set TIP.

Always go with your gut, when the little hairs on the back of your neck stand up something is wrong. Better to go with the sure TIP and advance the line then come flopping out of the tree from several stories up when your "maybe" TIP fails. Sounds like you did good.

 

[treesquirrel]

In cases such as this I will endure the extra effort of just advancing my line as I ascend the tree. No climb is worth your life my friend.

Slower and safer is much better than faster and dead.

 

[canopyboy]

Maybe I'm a bit cautious, but I want to be able to see the climbing line over the limb/crotch. My depth perception with the throwline up past 50 ft is a bit iffy, but I can usually see if the climbing line goes over properly. If it disappears into small stuff and comes back out, I just don't trust it. I've thought about looking through binos when I wasn't sure, but they weren't handy so I just pulled the line out and started over or went for a lower TIP. An alternative is what you did, and use a different way up the tree before you could inspect.

I would also definitely trust the hairs on my neck if they were up, but they only work about 1/2 the time....

 

[tree md]

Maybe I'm a bit cautious, but I want to be able to see the climbing line over the limb/crotch. My depth perception with the throwline up past 50 ft is a bit iffy, but I can usually see if the climbing line goes over properly. If it disappears into small stuff and comes back out, I just don't trust it. I've thought about looking through binos when I wasn't sure, but they weren't handy so I just pulled the line out and started over or went for a lower TIP. An alternative is what you did, and use a different way up the tree before you could inspect.

I would also definitely trust the hairs on my neck if they were up, but they only work about 1/2 the time....

Yeah, in a normal working situation, where I was doing a prune and needed to ascend on a rope I would have just reset the line. I was kind of itching to get in the tree and check out my new saddle so I just strapped on my gaffs since the tree is to be removed anyway. I definitely make sure I can visually inspect my TIP before I ascend. Binos are a good idea. Especially with all the cracked and split limbs we have in my area from storm damage. I usually like to use a friction saver with my PI rope as well. I think I am going to go ahead and bite the bullet and buy the tree frog system so I can SRT up the tree without having to isolate a limb. Just figured I would post this in hopes that it might help someone else.

 

[canopyboy]

I've just started SRT to get up, and it is SO much easier. Shoot your line over a branch, tie it off, and go up. That's it. Plus you don't have the friction of the line going over the branch, or even the friction saver.

I've been using the grigri and what I found as the yo-yo system? There may be other names for it.

http://www.newtribe.com/documents/tip4.htm

Looking up the tree frog system, that looks pretty trick too, but the grigri lets you come down on the same system.

'Course, I'm just starting this SRT stuff myself.

 

[tree md]

I've got a CMI foot ascender and Black Ice hand ascender. I have done a little SRT with that but it's not ideal. The CMI foot ascender is kind of a pain because it will not attach midline and the Black Ice ascender only has one hole for prussic attachment. I think I am just going to go ahead and get the proven frog system since I am using a Petzl saddle now that is set up for it. There is not much I can't do with Ddrt but I have to admit, there are situations where I can see where SRT would be easier and make a lot more sense.

 

[tree md]

I've just started SRT to get up, and it is SO much easier. Shoot your line over a branch, tie it off, and go up. That's it. Plus you don't have the friction of the line going over the branch, or even the friction saver.

I've been using the grigri and what I found as the yo-yo system? There may be other names for it.

http://www.newtribe.com/documents/tip4.htm

Looking up the tree frog system, that looks pretty trick too, but the grigri lets you come down on the same system.

'Course, I'm just starting this SRT stuff myself.

OK, I have read a little about the RADS system. For some reason I was thinking that they call it a yo yo when they incorporate a bungee lanyard into the system. Don't know why but I read that somewhere.Looks like a pretty slick setup. 3:1 system?

 

[canopyboy]

OK, I have read a little about the RADS system. For some reason I was thinking that they call it a yo yo when they incorporate a bungee lanyard into the system. Don't know why but I read that somewhere.Looks like a pretty slick setup. 3:1 system?

Yeah, I guess it's a 3:1, hadn't really thought about it. I can actually go up pretty fast even when I tried it without using a foot strap, because of the mechanical advantage I guess. I like the fact that it's simple, few parts (I don't use the strap between the ascender and grigri), and I can descend on it easily. I'm not as tired after going up 70ft like compared with the DRT, and I get there faster. Plus rigging a line is much easier, especially where there are a lot of branches to work your line back to you through. Like I said though, I'm still learning myself. I'd like to try it on some taller trees when I have some more time to play around.

The only thing that bothers me is how hot the grigri can get. It says it's limited to descents of 150' because of the heat build up, but it gets up there after even 40-50' if you descend very fast. There's only so much mass there to absorb the heat.

 

[John Paul Sanborn]

SRT can double the load on the TIP, so my being around 250# makes it undesirable. Even with multiple crotches, I find that what is desirable in a DdRT system will bend way too much for me on SRT.

I have broke out a 4 inch willow limb while bounce testing it. A buddy of mine, who is much smaller, broke out a red oak limb on his SRT line, even though it was double crotched.

To me it is not just diameter, but the angle of the parent stem also. I will tie into smaller unions if they are vertical.

 

[canopyboy]

SRT can double the load on the TIP, so my being around 250# makes it undesirable. Even with multiple crotches, I find that what is desirable in a DdRT system will bend way too much for me on SRT.

I have broke out a 4 inch willow limb while bounce testing it. A buddy of mine, who is much smaller, broke out a red oak limb on his SRT line, even though it was double crotched.

To me it is not just diameter, but the angle of the parent stem also. I will tie into smaller unions if they are vertical.

Yeah, the double loading of the TIP (minus friction) is a good reminder. I forgot to mention that -- thanks.

 

[mic687]

I posted pics in the 101 forum of a maple that I had a bad feeling about. Put a rope in it and knew I did'nt want to climb it and was glad I didn't. Good wood at the bottom and good wood up top bad about 3'-4' up and would not have held me. I would always rather go with my gut and not climb something I could have than ignore it and fall from something I should'nt have climbed.

 

[John Paul Sanborn]

Yeah, the double loading of the TIP (minus friction) is a good reminder. I forgot to mention that -- thanks.

Double loading occurs only when the lines are parallel; so if you have a double crotch that puts your entry angle at 45 degrees you will have much less. My library is in a box, in the attic, so I cannot pull out On Rope for the exact figures.

 

[canopyboy]

Double loading occurs only when the lines are parallel; so if you have a double crotch that puts your entry angle at 45 degrees you will have much less. My library is in a box, in the attic, so I cannot pull out On Rope for the exact figures.

I'll have to go back and look tonight, but I don't remember seeing that exact number in Smith and Padgett's book. I'm also not sure what double crotching has to do with an SRT loading of a crotch/branch, perhaps I'm not understanding what you're saying.

But from an engineering POV, the loading on a crotch (assuming no friction so that tension is constant along the entire line) can be calculated as follows. Call the angle between your up and down lines alpha. When the lines are parallel, alpha = 0, if you had your down rope tied off horizontally you would have alpha = 90 degrees. Call the load on the end of the rope (you) L. The formula to calculate the reaction load on your TIP would be:

TIP = 2*L*cos(alpha/2)​

When the lines are parallel, the load on the TIP is 2L or double. If lines are 90 degrees apart, your TIP load is 1.41L. If the lines are 45 degrees apart, your TIP load is 1.85L. Since lines in an SRT setup are rarely more than 45 degrees, it is easier to just use 2L or double the load. Note that this math is exactly the same as for lowering over a crotch or through a block. Actually, the calculation is the same for DRT too, but you are spreading your load over two ropes, so the load going into the equation is half.

To address double crotching, things go the other way. Your total load on the branch actually goes up with the angle. Your vertical load stays the same, but you start adding a bigger and bigger horizontal load. I can give the equations for that too, but it might be easier to think of tensioning a line. You can never tension a line enough to make it perfectly straight. The weight of the line causes it to sag at least a little. A small weight in the middle of the line makes this much more visible. Mathematically as you approach pure horizontal you are in effect dividing by zero, or bringing the line tension to infinity.

 

[tree md]

Double loading occurs only when the lines are parallel; so if you have a double crotch that puts your entry angle at 45 degrees you will have much less. My library is in a box, in the attic, so I cannot pull out On Rope for the exact figures.

I just ordered that book. I figured I aught to study a little more before I start trusting my life to ascenders and whatnot. I've heard nothing but good about the book. I know TD over at the buzz speaks highly of it.

 

[moss]

OK, I have read a little about the RADS system. For some reason I was thinking that they call it a yo yo when they incorporate a bungee lanyard into the system. Don't know why but I read that somewhere.Looks like a pretty slick setup. 3:1 system?

Yo-yo and RADs are the same system. It's 3:1 if you only pull on the rope coming out of the Grigri. The normal use is 1:1 which is grab the ascender with one hand, stand up on the footloop, pull the the rope below the Grigri with the other hand at the same time you're standing on the footloop. After you stand up repeat the cycle again. The Grigri captures your progress so you can sit back and rest at any point. The ascender doesn't need to be tethered to your harness, it's better if it's not.
-moss

 

[moss]

I don't know what happened but the line should have been isolated around a good limb in the fork. As it were, it looked as if I had shot both ends of the line through the same fork, even though I saw one go over and one go under

There's no "should have been" right? I have a small pair of binoculars to inspect high TIPs before I get on rope. If you can't see the rope in the TIP you're gambling.
-moss

 

[tree md]

There's no "should have been" right? I have a small pair of binoculars to inspect high TIPs before I get on rope. If you can't see the rope in the TIP you're gambling.
-moss

My sentiments exactly.

 

[John Paul Sanborn]

not sure what double crotching has to do with an SRT loading of a crotch/branch,

It also has to do with how the load is applied and distributed, I have an intuitive understanding, but lack the vernacular to describe it.

You are drawing the two crotches together, so it acts like a tie-back...

 

[TreeClimber57]

OK, I have read a little about the RADS system. For some reason I was thinking that they call it a yo yo when they incorporate a bungee lanyard into the system. Don't know why but I read that somewhere.Looks like a pretty slick setup. 3:1 system?

It is a great system, one I now use on regular basis. I

If I am not mistaken the Yo-Yo and RAD terms are interchangable.

I have only recently begun using it, but here is an article for you to review which gives a bit of history, etc.. at least one point of view.

http://www.newtribe.com/documents/tip4.htm