- Location
- Gatineau, QC
Petzl preliminary research
- Thread starter treebing
- Start date
- Location
- Retired in Minneapolis
Re: Petal preliminary research
That's the RE Load Cell Petzl used for the testing. Amazing tool!
That's the RE Load Cell Petzl used for the testing. Amazing tool!
- Location
- Retired in Minneapolis
Re: Petal preliminary research
AJ Nick
Oceans and I were talking about that issue. He suggested adding a load cell on each side of a TIP and apply a load. That would determine the amount of energy dissipated in friction.
Something to remember about ropes is that their performance characteristics change in a curve as the percentage of breaking strength is achieved. The specs at 10% of breaking strength are NOT five times less than the specs at 50% of breaking strength. Getting good numbers that have some meaning and application are kind of tough sometimes.
AJ Nick
Oceans and I were talking about that issue. He suggested adding a load cell on each side of a TIP and apply a load. That would determine the amount of energy dissipated in friction.
Something to remember about ropes is that their performance characteristics change in a curve as the percentage of breaking strength is achieved. The specs at 10% of breaking strength are NOT five times less than the specs at 50% of breaking strength. Getting good numbers that have some meaning and application are kind of tough sometimes.
treebing
Been here much more than a while
- Location
- Detroit, Mi.
Re: Petal preliminary research
What an awesome tool. This tool is just another piece of kit that allows us as climbers to do our own meaningful testing to make decisions and not have to rely on european "test laboratories" to keep us safe.
What an awesome tool. This tool is just another piece of kit that allows us as climbers to do our own meaningful testing to make decisions and not have to rely on european "test laboratories" to keep us safe.
Richard Mumford-yoyoman
Been here a while
- Location
- Atlanta GA
Re: Petal preliminary research
First of all there all just questions.
I would propose this, you're comparing a system that is designed to take a fall every time, to a system that should be designed never to take a fall,
Second of all, if you apply the results of this study to rigging, and climbing, I think it is like saying, will I die instantly, or will I die later after I have been folded in half backwards.
Does one take this information to design a system that is efficient and does not have slack or for when you take a major fall or your anchor breaks.
And when I say you or your, I'm referring to climbers in general of course.
I'm trying to wrap my head around the use of this information, given the extreme variables in which it is obtained.
First of all there all just questions.
I would propose this, you're comparing a system that is designed to take a fall every time, to a system that should be designed never to take a fall,
Second of all, if you apply the results of this study to rigging, and climbing, I think it is like saying, will I die instantly, or will I die later after I have been folded in half backwards.
Does one take this information to design a system that is efficient and does not have slack or for when you take a major fall or your anchor breaks.
And when I say you or your, I'm referring to climbers in general of course.
I'm trying to wrap my head around the use of this information, given the extreme variables in which it is obtained.
treebing
Been here much more than a while
- Location
- Detroit, Mi.
Re: Petal preliminary research
Well I think the main conclusion is that there are a lot of variables and you have to get away from, climbing on SRT with a base tie doubles the load. There are more factors than that. Are you going to break out the top of the tree? I think that is what I get out of the tests. It takes a rule that is commonly talked about and given as one of the reasons not to use a base tie. It's not 100% more, a more realistic number is 50%. Throw some angles in there it's even less. It's true that big dynamic falls are pretty rare in tree climbing but not unheard of. We are a work positioning profession not fall arrest. On top of that, all of our tools will slide and dissipate energy. These tests don't even factor that in. Not complicated tests. Nothing groundbreaking. It's cool that it was done and I would like to do it on my own climbing.
Well I think the main conclusion is that there are a lot of variables and you have to get away from, climbing on SRT with a base tie doubles the load. There are more factors than that. Are you going to break out the top of the tree? I think that is what I get out of the tests. It takes a rule that is commonly talked about and given as one of the reasons not to use a base tie. It's not 100% more, a more realistic number is 50%. Throw some angles in there it's even less. It's true that big dynamic falls are pretty rare in tree climbing but not unheard of. We are a work positioning profession not fall arrest. On top of that, all of our tools will slide and dissipate energy. These tests don't even factor that in. Not complicated tests. Nothing groundbreaking. It's cool that it was done and I would like to do it on my own climbing.
Richard Mumford-yoyoman
Been here a while
- Location
- Atlanta GA
Re: Petal preliminary research
Yes Kevin and that's exactly what I understand. It's as if all of this information is being presented to try to dispel SRT as a bad thing or having these disadvantages. Tom has been trying to tell everybody that for 20 years. It seems that most people or so many look at SRT with some kind of bias. I came into this late in the game so I never developed the bias or did I learn the way it's "supposed" to be done. To me SRT is like walking up the stairs as opposed to building some kind of mechanical advantage that has friction to help pull you up the stairs. (Maybe needed at some point in life but not by the guys I see climbing trees)
It is so much more efficient, it has so many more options, you can base anchor, you can canopy anchor, you can spread the canopy anchor to make weak branches support your weight, you can fold your rope over at any moment and make it DdRT, it can be done for the same cost, with the addition of a small prusik and caribiner you can quickly go to a 3:1 mechanical advantage, better than the 2:1 DRT. Oh, and I didn't even touch on redirects!! As you know the list goes on.
SEE AND THIS IS WHAT I DON'T GET, IT JUST SEEMS LIKE SUCH A CLEAR ADVANTAGE AND YET YOU HEAR SO OFTEN, "WELL I DON'T KNOW…"
SRT has soooooo many more options.
Not that DdRT is not useful, it has a place but to me these two methods are backwards in applied use.
Just my "unbiased" and perhaps less experienced opinion.
.
Yes Kevin and that's exactly what I understand. It's as if all of this information is being presented to try to dispel SRT as a bad thing or having these disadvantages. Tom has been trying to tell everybody that for 20 years. It seems that most people or so many look at SRT with some kind of bias. I came into this late in the game so I never developed the bias or did I learn the way it's "supposed" to be done. To me SRT is like walking up the stairs as opposed to building some kind of mechanical advantage that has friction to help pull you up the stairs. (Maybe needed at some point in life but not by the guys I see climbing trees)
It is so much more efficient, it has so many more options, you can base anchor, you can canopy anchor, you can spread the canopy anchor to make weak branches support your weight, you can fold your rope over at any moment and make it DdRT, it can be done for the same cost, with the addition of a small prusik and caribiner you can quickly go to a 3:1 mechanical advantage, better than the 2:1 DRT. Oh, and I didn't even touch on redirects!! As you know the list goes on.
SEE AND THIS IS WHAT I DON'T GET, IT JUST SEEMS LIKE SUCH A CLEAR ADVANTAGE AND YET YOU HEAR SO OFTEN, "WELL I DON'T KNOW…"
SRT has soooooo many more options.
Not that DdRT is not useful, it has a place but to me these two methods are backwards in applied use.
Just my "unbiased" and perhaps less experienced opinion.
.
Re: Petal preliminary research
I'm interested to see what happens with using two load cells; one on each side of a union. I'd like to understand how the diameter of a union relates to friction/load at TIP/etc...
Does anyone want to go in and share the cost to acquiring some of these load cells and get together for some testing?
I'm interested to see what happens with using two load cells; one on each side of a union. I'd like to understand how the diameter of a union relates to friction/load at TIP/etc...
Does anyone want to go in and share the cost to acquiring some of these load cells and get together for some testing?
Crazy_Jimmy
Participating member
- Location
- Texas
Re: Petal preliminary research
Kevin I prefer A Basal tie off when I climb work the tree SRT. But one of my concerns is wounding the Primary tip that my line is over . Just curious do you install a Cambium saver or something like that ?
Kevin I prefer A Basal tie off when I climb work the tree SRT. But one of my concerns is wounding the Primary tip that my line is over . Just curious do you install a Cambium saver or something like that ?
Richard Mumford-yoyoman
Been here a while
- Location
- Atlanta GA
Re: Petal preliminary research
[ QUOTE ]
I'm interested to see what happens with using two load cells; one on each side of a union. I'd like to understand how the diameter of a union relates to friction/load at TIP/etc...
Does anyone want to go in and share the cost to acquiring some of these load cells and get together for some testing?
[/ QUOTE ]
I'm interested.
For just measuring friction and weight I find the inexpensive digital scales pretty effective and they don't cost 700.00, about 120.00
.......but they are not life support so you must loop your climbing line around it in case it fails, also they are good to only 440 pounds so not going to do a drop test.
Eric, PM me.
last spring did a little testing with this scale
[ QUOTE ]
I'm interested to see what happens with using two load cells; one on each side of a union. I'd like to understand how the diameter of a union relates to friction/load at TIP/etc...
Does anyone want to go in and share the cost to acquiring some of these load cells and get together for some testing?
[/ QUOTE ]
I'm interested.
For just measuring friction and weight I find the inexpensive digital scales pretty effective and they don't cost 700.00, about 120.00
.......but they are not life support so you must loop your climbing line around it in case it fails, also they are good to only 440 pounds so not going to do a drop test.
Eric, PM me.
last spring did a little testing with this scale
- Location
- Retired in Minneapolis
Re: Petal preliminary research
In all of the years of using a base tie without any friction device I have never seen rope damage to the tree other than flaking off corky bark. I'm sure that there has been some that I might not have seen though. If I were to set a TIP in thin barked trees I would always use some sort of device
In all of the years of using a base tie without any friction device I have never seen rope damage to the tree other than flaking off corky bark. I'm sure that there has been some that I might not have seen though. If I were to set a TIP in thin barked trees I would always use some sort of device
Crazy_Jimmy
Participating member
- Location
- Texas
Re: Petal preliminary research
Tom dont take this the wrong way but how do you know,do you go back up and check every trees Primary tip ? Im just more concerned with wounding because of Oak wilt around our area and like you said soft bark trees.
Tom dont take this the wrong way but how do you know,do you go back up and check every trees Primary tip ? Im just more concerned with wounding because of Oak wilt around our area and like you said soft bark trees.
- Location
- Retired in Minneapolis
Re: Petal preliminary research
Jimmy
I didn't make it clear. Sorry. The ones that I have seen, which is a lot over the years, didn't show damage. I've wanted to see damage too so I've looked for it when I've climbed to a TIP. I have seen damage from natural crotch DdRT
Jimmy
I didn't make it clear. Sorry. The ones that I have seen, which is a lot over the years, didn't show damage. I've wanted to see damage too so I've looked for it when I've climbed to a TIP. I have seen damage from natural crotch DdRT
countryboypa31
New member
- Location
- PA
Re: Petal preliminary research
Ive seen damage to some of my TIP. Also at the charlotte comp two years ago we noticed damage at a TIP of the masters tree and thought some one dry crotched with Ddrt. later to find out it was the TIP for the one individual that set up the masters climbing SRT.
For a while i was using a cambium saver, not hard to set up but only protects the TIP any redirects are unprotected.
For the Record i've also seen minor damage from just ascending on SRT. Its a constant battle.
Ive seen damage to some of my TIP. Also at the charlotte comp two years ago we noticed damage at a TIP of the masters tree and thought some one dry crotched with Ddrt. later to find out it was the TIP for the one individual that set up the masters climbing SRT.
For a while i was using a cambium saver, not hard to set up but only protects the TIP any redirects are unprotected.
For the Record i've also seen minor damage from just ascending on SRT. Its a constant battle.
Re: Petal preliminary research
I think that larger diameter, more supple lines will cause less damage to sensitive bark. I've really only seen minor damage to Maples during Spring. If you plan your climb with a base anchor, use a conduit from Dan House for the primary TIP like Derrick said. You can also plan out a canopy anchor strategy with a stopper against a Rr FS and set false redirects in the canopy (sling/'biner).
I think that larger diameter, more supple lines will cause less damage to sensitive bark. I've really only seen minor damage to Maples during Spring. If you plan your climb with a base anchor, use a conduit from Dan House for the primary TIP like Derrick said. You can also plan out a canopy anchor strategy with a stopper against a Rr FS and set false redirects in the canopy (sling/'biner).
- Location
- Retired in Minneapolis
Derrick,
This is something that I pay attention to.
when you say 'damage' what do you mean?
What species of tree?
What was the diameter of the TIP?
This is something that I pay attention to.
when you say 'damage' what do you mean?
What species of tree?
What was the diameter of the TIP?
moss
Been here much more than a while
- Location
- Carlisle, Massachusetts, U.S.
I've seen base anchor system damage on the high anchor on beech and white pine. I've seen damage from natural redirects on beech. The damage is on small upper limbs that have the thinnest bark. On redirected natural crotch setups there can be significant rope movement/rubbing. Doing false crotch redirects or locking off natural redirects solves it.
By damage I mean surface bark abraded, green cambium layer exposed.
I've mentioned this before to to Tom, on white pine a base anchored rope can saw right into the cambium of young limbs, primarily from a climber dynamically loading during ascent. I've seen it enough times, I should've photographed it. It's not surprising, young white pine bark is very thin and soft.
I've only seen "polishing" on oak species base anchor/upper anchor and redirects.
I suspect that in general there is more damage to trees of any species by climbers simply busting though small branches in trees, as they climb SRT or DRT.
-AJ
By damage I mean surface bark abraded, green cambium layer exposed.
I've mentioned this before to to Tom, on white pine a base anchored rope can saw right into the cambium of young limbs, primarily from a climber dynamically loading during ascent. I've seen it enough times, I should've photographed it. It's not surprising, young white pine bark is very thin and soft.
I've only seen "polishing" on oak species base anchor/upper anchor and redirects.
I suspect that in general there is more damage to trees of any species by climbers simply busting though small branches in trees, as they climb SRT or DRT.
-AJ
- Location
- Retired in Minneapolis
This is great! Since I haven't done much climbing in small white pines for pruning I don't have a record there...same for beech. Some of this damage will be very species specific. Along with that, how high in the canopy is the TIP/Redis?
WE can't go wrong using some sort of false crotch.
WE can't go wrong using some sort of false crotch.
countryboypa31
New member
- Location
- PA
Locust have to be one of the more common that i've seen damage in. It was an oak that was used as a masters climb that i saw damaged. The cambium saver def helps.
- Location
- Minneapolis
I would echo moss on the white pines. I have climbed some big ones and have had a chance to look. Using base tie, 80' TIP, PI and Dragonfly, I see a channel/groove and maybe the cambium exposed a bit. Definitely some wear and tear. I'm next to the trunk on perhaps 4" dia. limbs. I imagine the rope moving slightly across the limb with the stretch. Don't know if that's the case but will check it out next time.
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