TreeClimber57
Addicted to ArboristSite
Agreed..
They know what is going on and why, they can anticipate things that could or will happen, they THINK..
And, in an emergency many of them could still climb up (maybe with spurs) and help out.
Lowering wood with bull rope
- Thread starter TreeandLand
- Start date
Help Support Arborist Forum:
Agreed..
They know what is going on and why, they can anticipate things that could or will happen, they THINK..
And, in an emergency many of them could still climb up (maybe with spurs) and help out.
TreeClimber57
Addicted to ArboristSite
A lot of new or younger climbers have trouble estimating the actual weight of any wood.. I have a chart around somewhere but I can not find a soft copy of it right now.
Part of battle is understanding the weight of block, then getting the concept of what that would change into energy wise during a shock load in rigging.
ropensaddle
Feel Lucky
Yes I have green wood chart so it is easy for approximate weight. It starts as potential energy the turns kinetic and has gravity bearing on it at 32 foot per second per second before run turns it into friction. I understand the principals but have forgotten the math! I learned without any of the formula's but am sure I have put many ropes past the wll. I am a bit more careful now and just use a ten times rule 800 = 8000 with some run.
sgreanbeans
Treeaculterologist
I like that! Put it on yur laptop and take wit ya?
I can do the math in my head, have been doing it for along time too, but that program is neat, I gunna get me won does! Anything from ArborMaster is pretty good, have learned a lot from those 2!
sgreanbeans
Treeaculterologist
I have been grounding for my climber, he is loving it. Don't have to explain what he is doing, no talk, just hand signals. I am having a blast! Teaching the yunging the "ropes", pun intended! He is still a little nervous on the bigins, but getting better everyday, his timing is pretty good, doing a good job of getting it away from my climber. Its fun showing them the tricks and watching for that point of enlightenment, you get a look from them that tells you the bulb over their head is on! " oh that's cool, show me again!"
I agree, it's great to work with another climber running your ropes. We were a small Co and were lucky enough to have a pretty good work force to draw from. Many guys floated around from Co to Co and were known, with good or bad reps. We'd cherry pick the good guys. A groundie would probably be on the crew a year before he was allowed to do any real tricky roping. I also started when we were using manilla or hemp rope, and porta wraps were a thing of the future. When I retired we were using New England Rope exclusively. We used 5/8 and 3/4 braid bull line. All of our rigging was through crotches and wraps on trees. I don't remember ever breaking any braid, I do remember poppin big old manilla. Another thing we had to think about were the crotches. A crotch could often fail long before the rope, and we didn't want to burn the bark/cambium. If I had to work with a newbie I would take partial raps in the tree to control the fall in case he froze up. Either leave a foot or two loop in front of my notch or a loose wrap leading into the crotch. There's a lot you can do up in the tree to set up the rope man in case he doesn't quite know what you want. If you're both new and inexperienced expect lots of loose teath and buckin bronco rides, Joe.
TreeClimber57
Addicted to ArboristSite
Yep, we used manilla until the 80's.. still have a couple of rolls of it in shop. Thinking back, a lot has changed in 20-30 years.
eye.heart.trees
arborjunky
Sorry to resurrect this but it's just so on-point with the thread I *would've* made on this topic!
Any links you have for understanding things would be incredibly useful, have been having a helluva time trying to select bull line for my new "heavy duty" rigging setup, my contention/problem is that I look at 90% of the ropes marketed, see ~1-2% elasticity, and think "that's dangerously static, shock-loads could shatter that surprisingly easily"
Our rigging lines are more static than our climb lines....wth?!? People recognize the difference between static/tensile strengths and dynamic strengths enough to know that, despite an impressive STATIC strength, the 0.5% elasticity of dyneema('amsteel') makes it useless for rigging-lines or rigging-slings....was face-palming so hard when watching a video where a guy describes how he broke his ~3/8" or 1/2" amsteel sling and his response was to get 3/4" or 1" amsteel, as-if upping the STATIC capacity of the line somehow meant it'd be better for the dynamic forces experienced when "shock loaded".
These lines are marketed for rigging which INHERENTLY includes 'shock loading' (vague term....'dynamic loading' is inherent to the downward control, with ropes, of a piece of wood you've just cut. Doesn't matter how skilled the groundie is, hell even having a positive-line-angle from the rigging-anchor to the piece to negate hard dynamic forces['shock loading'] doesn't mean you've got 0 dynamic force it just greatly minimizes it, but being able to tie&lift a branch to cut it, then lower it gently, is obviously something that's nice-when-possible but more often than not is NOT the way to properly rig something) So, if they're for rigging, how come they're so damn static?
Looks like Yale's 3% polydyne is a great step forward (surprised double esterlon still sells, cannot even come up with a use-case where you'd want it over polydyne, yet it's still sold and actually sometimes more-expensively than the polydyne!), then Sterling comes out with Atlas which is **50%** more elastic than the next-stretchiest rope (4.5%, compared to polydyne's 3%) and, no shock (lol, punny) to me, that line is getting incredibly popular.
What I cannot reconcile is "Why, after decades of doing this type of production, why aren't the elasticity #'s of these bull lines dialed-in yet?" I mean, I'd bet $$$ all day long that if I got a retailer's catalogue from 10yrs in the future, I'd bet any amount of $$ that the average elasticity of the bull lines will be greater than it is today. That said, the 1.1% elasticity "Stable Braid" line is incredibly popular, I look at it and am blown away that anybody would choose it for rigging, I understand using it for winching/liftting/hauling/mech-advantage setups but for routine-rigging IE what we'd use these ropes for 95% of the time, the "SWL/WLL" concept IS UTTERLY FLAWED!!
People say "Oh, this rope's STATIC strength is 10k, ergo I'm being conservative by keeping my loads under 1k", these SWL's/WLL's ignore dynamic conditions / the shock-absorption-capacity of the ropes, it seems so clearly-misguided to me that I'm genuinely unable to figure it out (IE I'd expect that anyone looking for a bull line would say "atlas or polydyne, nothing else" yet the stiff samson stable braid is incredibly popular!)
This video by Yale is fantastic (though it makes me wonder why their most-elastic line is still just 3%), shows the same force (a 220lbs load taking a 6' free fall, equating to 1,400lbs dynamic force when it hits that 6') on two ropes, one is a 20k ABS sling-type rope (ultrex or yalex, their version of what samson calls 'tenex') and the other is a 6k ABS climb-line (XTC), it's a great illustration of just how important this static-versus-dynamic concept is as the 20k ABS line snaps on the first try, while the 6k ABS line can take the load over&over..... Video is on the bottom of their article here: http://www.yalecordage.com/featured-industries/arborculture/dynamic-energy-arborist-rope
I'm not ordering anymore of the 1.5% yalex/tenex slings, a sling should be more-capable than the bull-line it supports, **IMO** this doesn't just mean a thicker line (if using identical cordage construction) but also means it'd be optimal to have slightly different cordage IE more-elastic, I want my anchor-slings to be at least 20% stronger than what I'll be using the line for, so if it were static-only (generally inapplicable to our purposes) then I'd want a 12k sling supporting anchorage for my 10k line. For our uses, I'd apply the same logic only I'd add that, if my bull line were 3%, I'd like 3.25% on the sling -- the strength of ropes when it comes to dynamic loads is a function of many things but length-of-line to take the shock is an important variable, so given that the slings have such short lengths they necessitate being a higher elasticity line to have the same relative shock-mitigation that a more-static, but longer length, line of bull rope had!
I'd probably be choosing Atlas if Yale made it, however I'm a Yale supporter and their Polydyne is the 2nd-best specs (on-paper, 2nd to Atlas) on the market, was planning to get like 40' of Yalex with the polydyne to make slings but am now thinking I'm just going to order a longer spool of polydyne and make my slings from that (*NOTE*- I'd only be using 'basket configuation' type slings IE no chokers, this means I'm using both legs of the sling therefore it's stronger than single-line usage, so I do get the stronger-than-rig-line attribute here anyways)
~~~~~~~~~
Would love anyone's thoughts, especially recommendations on choosing between the 5/8" (19k ABS wtih 3% elast.), or the 3/4" (26k ABS with 3% elasticity), polydyne!! I'd been thinking the 3/4" would be overkill, but with 5/8" being 19k ABS, and reading someone in this thread saying they felt their 3/4" stable braid was insufficient (that 3/4" has static-strength equivalent to a 5/8" polydyne cord), has me of two minds.....on one hand, I think "well, if their ~20k line was Poly instead of SB, the nearly 3X more elastic polydyne would be fine for them", making me think to get 5/8".....the other part of me thinks "it's a bit more expensive, and heavier, but 3/4" polydyne seems about the best on the market, you could do double-safebloc-rigging with the stuff, when in-doubt go for redundancy/overkill!" --- would love to hear thoughts, I've gotta place this order by the weekend I've researched long enough now, am awaiting replies to a physics thread on this subject as well as a couple more rope-manufacturer replies (emails) to really get this, but honestly when considering the guy who said he felttt his 3/4" stable braid (1.1% elasticitty!) felt insufficient for him, I have to wonder if he'd had the 5/8" poly instead (same tensile but triple the elasticity/shock-absorpttion-capacity) whether he'd still have felt the same....I know I'd take ***1/2"*** polydyne over 3/4" stable braid, I know that my STATIC capacity would only be 50% of the Stable Braid but if you factor in the elasticity/shock-absorpttion of the line it becomes clear you can snub higher loads with the 1/2" polydyne than you could with **3/4"** of the ever-popular Stable Braid! (again please watch video at end of the Yale ^ link I posted....that 20k ultrex line that snapped was a 0.5% elasticity line so it snapped *despite* its 20k *static* ABS while the 6k ABS XTC line around 1.6% elasticity, IMO that's still super-static at 1.6% but it still handled that dynamic load like a champ while the stiffer line snapped, I'm just astounded that sub-2% lines are used ANYWHERE in a rigging setup whether as bull-line, slings or anything, they've got no business being around dynamic loading!!!
Any links you have for understanding things would be incredibly useful, have been having a helluva time trying to select bull line for my new "heavy duty" rigging setup, my contention/problem is that I look at 90% of the ropes marketed, see ~1-2% elasticity, and think "that's dangerously static, shock-loads could shatter that surprisingly easily"
Our rigging lines are more static than our climb lines....wth?!? People recognize the difference between static/tensile strengths and dynamic strengths enough to know that, despite an impressive STATIC strength, the 0.5% elasticity of dyneema('amsteel') makes it useless for rigging-lines or rigging-slings....was face-palming so hard when watching a video where a guy describes how he broke his ~3/8" or 1/2" amsteel sling and his response was to get 3/4" or 1" amsteel, as-if upping the STATIC capacity of the line somehow meant it'd be better for the dynamic forces experienced when "shock loaded".
These lines are marketed for rigging which INHERENTLY includes 'shock loading' (vague term....'dynamic loading' is inherent to the downward control, with ropes, of a piece of wood you've just cut. Doesn't matter how skilled the groundie is, hell even having a positive-line-angle from the rigging-anchor to the piece to negate hard dynamic forces['shock loading'] doesn't mean you've got 0 dynamic force it just greatly minimizes it, but being able to tie&lift a branch to cut it, then lower it gently, is obviously something that's nice-when-possible but more often than not is NOT the way to properly rig something) So, if they're for rigging, how come they're so damn static?
Looks like Yale's 3% polydyne is a great step forward (surprised double esterlon still sells, cannot even come up with a use-case where you'd want it over polydyne, yet it's still sold and actually sometimes more-expensively than the polydyne!), then Sterling comes out with Atlas which is **50%** more elastic than the next-stretchiest rope (4.5%, compared to polydyne's 3%) and, no shock (lol, punny) to me, that line is getting incredibly popular.
What I cannot reconcile is "Why, after decades of doing this type of production, why aren't the elasticity #'s of these bull lines dialed-in yet?" I mean, I'd bet $$$ all day long that if I got a retailer's catalogue from 10yrs in the future, I'd bet any amount of $$ that the average elasticity of the bull lines will be greater than it is today. That said, the 1.1% elasticity "Stable Braid" line is incredibly popular, I look at it and am blown away that anybody would choose it for rigging, I understand using it for winching/liftting/hauling/mech-advantage setups but for routine-rigging IE what we'd use these ropes for 95% of the time, the "SWL/WLL" concept IS UTTERLY FLAWED!!
People say "Oh, this rope's STATIC strength is 10k, ergo I'm being conservative by keeping my loads under 1k", these SWL's/WLL's ignore dynamic conditions / the shock-absorption-capacity of the ropes, it seems so clearly-misguided to me that I'm genuinely unable to figure it out (IE I'd expect that anyone looking for a bull line would say "atlas or polydyne, nothing else" yet the stiff samson stable braid is incredibly popular!)
This video by Yale is fantastic (though it makes me wonder why their most-elastic line is still just 3%), shows the same force (a 220lbs load taking a 6' free fall, equating to 1,400lbs dynamic force when it hits that 6') on two ropes, one is a 20k ABS sling-type rope (ultrex or yalex, their version of what samson calls 'tenex') and the other is a 6k ABS climb-line (XTC), it's a great illustration of just how important this static-versus-dynamic concept is as the 20k ABS line snaps on the first try, while the 6k ABS line can take the load over&over..... Video is on the bottom of their article here: http://www.yalecordage.com/featured-industries/arborculture/dynamic-energy-arborist-rope
I'm not ordering anymore of the 1.5% yalex/tenex slings, a sling should be more-capable than the bull-line it supports, **IMO** this doesn't just mean a thicker line (if using identical cordage construction) but also means it'd be optimal to have slightly different cordage IE more-elastic, I want my anchor-slings to be at least 20% stronger than what I'll be using the line for, so if it were static-only (generally inapplicable to our purposes) then I'd want a 12k sling supporting anchorage for my 10k line. For our uses, I'd apply the same logic only I'd add that, if my bull line were 3%, I'd like 3.25% on the sling -- the strength of ropes when it comes to dynamic loads is a function of many things but length-of-line to take the shock is an important variable, so given that the slings have such short lengths they necessitate being a higher elasticity line to have the same relative shock-mitigation that a more-static, but longer length, line of bull rope had!
I'd probably be choosing Atlas if Yale made it, however I'm a Yale supporter and their Polydyne is the 2nd-best specs (on-paper, 2nd to Atlas) on the market, was planning to get like 40' of Yalex with the polydyne to make slings but am now thinking I'm just going to order a longer spool of polydyne and make my slings from that (*NOTE*- I'd only be using 'basket configuation' type slings IE no chokers, this means I'm using both legs of the sling therefore it's stronger than single-line usage, so I do get the stronger-than-rig-line attribute here anyways)
~~~~~~~~~
Would love anyone's thoughts, especially recommendations on choosing between the 5/8" (19k ABS wtih 3% elast.), or the 3/4" (26k ABS with 3% elasticity), polydyne!! I'd been thinking the 3/4" would be overkill, but with 5/8" being 19k ABS, and reading someone in this thread saying they felt their 3/4" stable braid was insufficient (that 3/4" has static-strength equivalent to a 5/8" polydyne cord), has me of two minds.....on one hand, I think "well, if their ~20k line was Poly instead of SB, the nearly 3X more elastic polydyne would be fine for them", making me think to get 5/8".....the other part of me thinks "it's a bit more expensive, and heavier, but 3/4" polydyne seems about the best on the market, you could do double-safebloc-rigging with the stuff, when in-doubt go for redundancy/overkill!" --- would love to hear thoughts, I've gotta place this order by the weekend I've researched long enough now, am awaiting replies to a physics thread on this subject as well as a couple more rope-manufacturer replies (emails) to really get this, but honestly when considering the guy who said he felttt his 3/4" stable braid (1.1% elasticitty!) felt insufficient for him, I have to wonder if he'd had the 5/8" poly instead (same tensile but triple the elasticity/shock-absorpttion-capacity) whether he'd still have felt the same....I know I'd take ***1/2"*** polydyne over 3/4" stable braid, I know that my STATIC capacity would only be 50% of the Stable Braid but if you factor in the elasticity/shock-absorpttion of the line it becomes clear you can snub higher loads with the 1/2" polydyne than you could with **3/4"** of the ever-popular Stable Braid! (again please watch video at end of the Yale ^ link I posted....that 20k ultrex line that snapped was a 0.5% elasticity line so it snapped *despite* its 20k *static* ABS while the 6k ABS XTC line around 1.6% elasticity, IMO that's still super-static at 1.6% but it still handled that dynamic load like a champ while the stiffer line snapped, I'm just astounded that sub-2% lines are used ANYWHERE in a rigging setup whether as bull-line, slings or anything, they've got no business being around dynamic loading!!!
eye.heart.trees
arborjunky
I'm surprised to hear that people have trouble estimating, it's never going to be perfect but it's literally just "width, height, wood-weight" (if someone's field-rigging without a green-weights list then they're either a vet who's beyond needing it, or they're ignorant and liable to hurt themselves/others/property) My problem is this whole concept of using STATIC strengths as the baseline-figure for our DYNAMIC loading calculations (dynamic loading is like 99% of the uses these ropes get, yet industry-norm is to focus on STATIC numbers....an ignorant person could be forgiven for thinking they were OK to drop a 1k log, after 3' of free-fall, because they were using 3/4" amsteel.....made-up #'s but you get the point, amsteel/dyneema snaps under dynamic loading it's for static use only, but our general approach would put amsteel as a viable contender when it simply is not)
You mention you learned without any of the formulas, so want to ask you, and anyone reading: Does anybody have any formulas for calculating things here?? I'm unable to find my scrap paper that had this amazing formula that accounted for rope-length in the system, elasticity etc, am dying to re-find this formula but *any* formulas would be useful!!!
PS-- does anyone think I'm shooting myself in the foot getting a 150' length of bull line? My current line (1/2") isn't even a full 100' as I've made a sling from it, and never once have I found I needed a longer line, so am thinking 150' is plenty for me....but then I glance at my new x-kit (rigging anchors for directing the line all over, meaning it won't be that short trunk-to-anchor-to-load that I currently do, will need an extra 5-30' of redirect length through the canopy, would love to hear people's thoughts on this!!!)
[AWESOME username/handle btw!!!!!]
eye.heart.trees
arborjunky
Silly Q but you didn't happen to find any guidelines for hand signals did you? I use walkie-talkies when needed but was recently thinking "Damn, with as few as like 5 hand-signals, I could have a rigging-sign-language method of communication with my groundsman!!", in hearing/reading your post here ^ I'm totally sold on the idea now and'll be trying to come-up with a good system / 'language', any&all specifics you could share would be greatly appreciated so I'm not 'rebuilding the wheel' that you've started
ropensaddle
Feel Lucky
The vet thingy does apply to me but then it doesn't as well. I have been in trees since 1982 my go to formula was cut it smaller for a good part of my mid career and especially after I was buying my ropes lol. I have dumped big stuff onto 3/4 double braid but the older I get the more careful I've become. As for production many times its faster to cut stuff smaller in my experience than to rig for very large gear testing loads. It also many times requires a seasoned groundsman to pull off big loads successful without jarring me around up there. I prefer to speedline now a day to get the mess clear of my decent but to tell the truth my career has taken a different path the last two years and I climb less and less as a result.
Similar threads
