# SRT/Rope Wrench Safety Advice



## ClimbMIT (Feb 13, 2012)

Okay, I have been really excited about using my Rope Wrench for access and pruning as well. I like the fact how your climbing hitch will not bind going around multiple crotches. I haven't played with it much though. I have read a lot of threads about the static ropes not designed for fall arrest and climbing line not designed for ascending, Rope Wrench threads and videos, rope options for SRT, really great information! What I was wondering is what kind of force is created on the rope each time you redirect your line? Does this create more stress and weight to the climbing line with each redirect? Also this seems like it would create a lot of wear on the rope. I want to utilize these new tools I just want to make sure that I understand the risk factors and know how to apply proper technique with this equipment.

Thanks!


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## Carburetorless (Feb 13, 2012)

ClimbMIT said:


> Okay, I have been really excited about using my Rope Wrench for access and pruning as well. I like the fact how your climbing hitch will not bind going around multiple crotches. I haven't played with it much though.



I can't comment on the Rope Wrench, I've never used one.



> I have read a lot of threads about the static ropes not designed for fall arrest and climbing line not designed for ascending, Rope Wrench threads and videos, rope options for SRT, really great information!



You don't fall while tree climbing(at least you're not supposed to), and you never use a dynamic(rock climbing line) for tree climbing, they're used to arrest falls while rock climbing.

You could a dynamic rope for rigging to absorb the shock load of a limb being lowered onto it, but you don't want to climb on one.



> What I was wondering is what kind of force is created on the rope each time you redirect your line? Does this create more stress and weight to the climbing line with each redirect?



If you place a rope around a limb or anything else, and pass it back down the other side at 180 degrees, and apply a load to one side, you will double that load on the line.

If you do that over multiple limbs, you will apply that force to multiple places on the rope; However, you won't be increasing the initial load. 

If you place the rope around a limb or whatever at 120 degrees or less you only put a force equal to the load on the part of the rope that's over the limb.

Something else you may not know, when you put a rope over something at 180 degrees only half of the rope is supporting the load, since ropes are designed to have strength along their length, when you bend the rope around a limb the inside of the rope becomes compressed, while only the outside of the rope is pulled by the load. So your ropes strength is reduced by half when you put it around an anchor point at 180 degrees.




> Also this seems like it would create a lot of wear on the rope. I want to utilize these new tools I just want to make sure that I understand the risk factors and know how to apply proper technique with this equipment.
> 
> Thanks!



Arborist ropes are pretty tough, but not indestructible. Examine your ropes before and after every use to check for signs of wear or damage. If it doesn't look safe replace it.


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## VA-Sawyer (Feb 13, 2012)

Carb,
So many of your statements about rope loads are wrong that I don't know where to begin.

A rope going up one side of a branch and back down the other does not increase the load on the rope, but it does increase the load on the branch supporting the rope.

A rope doesn't lose 1/2 of its strength going over a branch due to compression on the inside! In fact the strength loss is very minor if the diameter of the pulley/branch is at least 4 times the diameter of the rope.

There is nothing magical about the 120 degree angle on rope loads!

You really need to get a clue about physics before trying to tell others about rope loads.
Rick


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## Iustinian (Feb 13, 2012)

Bend ratio is the term that comes to mind.

HSA Rigging Report..." Rope Bend Ratio 7.3.4 When rope passes over an object (e.g. branch or pulley) the bend generated in the rope will result in uneven loading of the threads of the rope. The fibers on the inside of the bend will be compressed, and therefore they cannot participate in carrying the load in the same way as they would if the rope were straight..." ETC, which most know. Then the report quotes Blair, 1999 "Working rope over too small a sheave or tying off to an undersized bollard, for example, can cause both internal and external fibre fatigue and abrasion, creating potential for failure."

If your rope is hung on a branch that is 4x's greater than the diameter of the rope itself, then it will generally be accepted to be a sufficient bend ratio so as not to alter the strength of the rope in that situation. 

I agree: if you secure the standing part of the rope to the trunk, and do an srt ascent on the working end of the rope -- the branch will have to support 2x's the weight applied to the working end of the rope, that is double the climber's loaded weight, gear and all.


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## Carburetorless (Feb 13, 2012)

VA-Sawyer said:


> Carb,
> So many of your statements about rope loads are wrong that I don't know where to begin.
> 
> A rope going up one side of a branch and back down the other does not increase the load on the rope, but it does increase the load on the branch supporting the rope.
> ...



A rope's strength is along it's length when it's being pulled on, if you bend that rope at 180 degrees there is only about half the rope being pulled on, so yes it does lose half it's strength.

Stop being a keyboard jockey.


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## VA-Sawyer (Feb 13, 2012)

No it doesn't ! You might just do a little reading on the subject before saying such dumb stuff.

As for being a keyboard jockey....... I'm just trying to keep folks from getting injured or killed by WRONG infomation.
Rick

Dang! Del beat me to it.


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## ClimbMIT (Feb 13, 2012)

Thanks for the responses! I am going to read up on some of the rope dynamics.I figured this thread might get a good debate going. I am not taking any advice for granted. I am teaching myself these techniques that I watch videos on. So I take it seriously. Low and slow for now. When I get better. I will have to make a video of me climbing SRT and Rope Wrench. Then you guys will be like, " what the hell is he doing?! " or hopefully say, " Nice Video and technique"


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## Carburetorless (Feb 13, 2012)

VA-Sawyer said:


> No it doesn't ! You might just do a little reading on the subject before saying such dumb stuff.
> 
> As for being a keyboard jockey....... I'm just trying to keep folks from getting injured or killed by WRONG infomation.
> Rick
> ...



So your telling them that their rope is stronger than it actually is will keep them safer? 

Oh, my bad.:msp_confused:


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## tree md (Feb 13, 2012)

Carburetorless said:


> So your telling them that their rope is stronger than it actually is will keep them safer?
> 
> Oh, my bad.:msp_confused:



You're wrong man. You need to go back and hit the books.


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## tree md (Feb 13, 2012)

And just so you know, I was unclear on that a few years ago myself. And was told so here. Same discussion. I had to research it to be sure for myself.


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## VA-Sawyer (Feb 13, 2012)

I think we may be wasting our time trying to educate a 'clueless carb'.

Hey Clueless, have you ever seen the results of a splice test in a pulling machine ? The eye of the rope splice is bent 180 degrees over a pin at each end and then pulled to failure. I have never seen one break where it bent over the pin. They often fail at the end of the inserted tail which is straight.
Try explaining that with your 1/2 strength when bent 180 degrees crap.

Bad infomation is BAD no matter which side of the equation it falls on.

Rick


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## Bomber (Feb 13, 2012)

I file Carbs advice in the same class as FTA and AA.


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## VA-Sawyer (Feb 13, 2012)

Del_ said:


> It's bad to use the 'troll' word when not sure but I've felt 'trolled' right from the start with him.
> 
> 
> He was giving clues when he posted about dropping his srt line......going on about never DbRT'ing and never learning how to hip thrust. IMO, he's making it up for entertainment purposes and we are his entertainment, Keyboard Jockey.



Del_,
I haven't responded to his stuff before, but he was so wrong on this thread, I felt I had to in the name of safety. And just for the record...I can't hip thrust for beans.

Bomber, Ok, I got it now. CC,AA and FTA.

Rick


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## Iustinian (Feb 13, 2012)

VA-Sawyer said:


> I think we may be wasting our time trying to educate a 'clueless carb'.
> 
> Hey Clueless, have you ever seen the results of a splice test in a pulling machine ? The eye of the rope splice is bent 180 degrees over a pin at each end and then pulled to failure. I have never seen one break where it bent over the pin. They often fail at the end of the inserted tail which is straight.
> Try explaining that with your 1/2 strength when bent 180 degrees crap.
> ...



yea, absolutely correct. At one time Samson's (for those that don't know, the manufacturer of many quality rigging ropes lol) recommendations were a 8:1 bend ratio for load bearing applications, but allowed a 3:1 for pin termination. 

And carb-less -- you would be correct with the assumption that the rope is bent at 180 to the extent that it has been pinched; HOWEVER, it can be safely used during 180 degree turn, provided that the bend ratio is 4:1, that is, the bend occurs at a place (like in a properly selected pulley, or even a branch) if the turn provides at least the prescibed bend ratio.


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## VA-Sawyer (Feb 13, 2012)

Actually, climbers hang every day on ropes using less than a 4 to 1 bend radius. A knot on a biner and through the rings of a friction saver are just two that come to mind.
Rick


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## tree md (Feb 13, 2012)

I use biners and friction savers as little as I can get away with on my climbing line. I find that the bend radius is harder on my ropes than natural crotch. Don't get me wrong, I'll throw a FC on a limb for a redirect when I need to but I have found that the FS and biners make my PI milk and I don't like that.


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## VA-Sawyer (Feb 13, 2012)

I agree. I also climb on Hi-vy and use a spliced eye and that leather bark saver. Haven't had any milking issues.
Rick


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## Iustinian (Feb 13, 2012)

I've been using this as a redirect (for drt climbs) for awhile. The double pulley allows the rope to run past itself side by side without ever locking off, which has happened to me using redirects before -- avoiding that once was worth the extra $35 for the pulley. Plus it has a permanent spot on the gear racks on the back of my harness.


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## ClimbMIT (Feb 13, 2012)

VA-Sawyer said:


> I agree. I also climb on Hi-vy and use a spliced eye and that leather bark saver. Haven't had any milking issues.
> Rick



Thanks Sawyer, I appreciate your feedback along with Del. Do you use your leather bark saver for SRT on your highest tie in point?


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## VA-Sawyer (Feb 14, 2012)

I try to. It is always on my rope, so if I can easily get it over the TIP I will do so. However, as there is little rope movement on SRT, I don't fret too much if it is being a PITA. Sometimes I go up SRT and then change over and position the leather where I want it at that time.
Rick


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## Youngbuck20 (Feb 14, 2012)

There's a guy on YouTube called Ontarioclimber, he has lots of videos with the rope wrench, worth watching.


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## Carburetorless (Feb 14, 2012)

Iustinian said:


> And carb-less -- you would be correct with the assumption that the rope is bent at 180 to the extent that it has been pinched; HOWEVER, it can be safely used during 180 degree turn, provided that the bend ratio is 4:1, that is, the bend occurs at a place (like in a properly selected pulley, or even a branch) if the turn provides at least the prescibed bend ratio.



I never said it wouldn't be safe, I only said it's weaker than if it were being pulled straighter. The smaller the radios the less rope holding the load. 

Any time you put a bend on a rope the rope's strength is lowered for the duration of the load due to the fact that there is less of the rope's diameter holding the load.

4:1 and it's safe? Only if you stay within safe working loads, but just because a rope is rated at WLL: 810 doesn't mean you can put an 810 lb guy on the line. So you'd better use two ropes Ius.


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## VA-Sawyer (Feb 15, 2012)

Clueless Carb,

What you said was a 180 degree bend made a rope 1/2 as strong. You didn't just say weaker, you said it loses 1/2 of its strength. Just page up and read your own BS ! Just curious, do you also put cement in tee cavities ?

Rick


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## VA-Sawyer (Feb 15, 2012)

Carburetorless said:


> 4:1 and it's safe? Only if you stay within safe working loads, but just because a rope is rated at WLL: 810 doesn't mean you can put an 810 lb guy on the line. So you'd better use two ropes Ius.



Wrong again CC. WLL means that you can put a 810 lb guy on the line and be safe. You need to understand that WLL includes a safety factor that puts the limit well below the breaking strength of the rope. I have to say that Clueless fits you to a T.

Rick


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## Iustinian (Feb 15, 2012)

Technically -- we should all use two ropes according to ANSI; your work positioning/access line (depending on your climbing style) and an additional access line, in case the need for an aerial rescue arises -- makes for a faster safer rescue, assuming that you've performed an online test of the access line. 

Sawyer is correct again -- WLL is a factor. Working Load Limit is generally accepted to be 10% of the maximum break strength, assumed that there are no structural defects in the line. 

It is of note to mention that weight measured in pounds by itself is a crude and poor way to translate Kilo-newtons, by the way, when you understand that a kilo-Newton is a measure of force, and weight measured in pounds is strictly a measurement of gravity -- which is a concept deserving several hours of study in and of itself.

Anyhow -- generally accepted that our gear (ropes, harnesses, connectors) is to be rated at 5000 LBS, or roughly 23 kN. that is a WLL of 500 lbs, everyday use, accepted and endorsed by professionals internationally and no problem w/ ANSI and OSHA. 

OSHA requires fall protection systems on any work that is performed on a surface that is over 4ft from the ground. You show me the last 500 lbs employee (having roughly a factor of 2.2 kN, which I'm just being a smartass at this point) that has performed treework on a surface over 4 ft from the ground "with or without reasonable accommodation" hahahaha (ADA, right?) 

810lbs? that's like 4 whole climbers -- and what's crazy is -- that's the safe WLL of more than one climbline on the market today. Bluestreak specifically, which has a MBS of 8,100lbs

Carb, you said "Any time you put a bend on a rope the rope's strength is lowered for the duration of the load due to the fact that there is less of the rope's diameter holding the load." you are incorrect when you say ANYTIME. if the bend is made around a surface (AGAIN, like a pulley or even a branch) that provides at least a 4:1 bend ratio, there is no pinch, there is no loss of performance. Some rope manufacturers ask for a higher/lower bend ratio, depending on the particular application/use. 

Pin termination is usually accepted to be less.

(360)384-4669 Samson Rope
(207) 282-3396 Yale Rope

Call and ask, they'll usually be willing to talk to you and explain it.


No BS I've talked to them personally, and even the guy at Sherill that does most of the splicing. What takes me 2 hrs takes him like 15 minutes. less now probably. 

Study up -- its interesting stuff if you have the time, and your life depends on it.


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## sgreanbeans (Feb 15, 2012)

Dinked Carb for unsafe info.


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## ClimbMIT (Feb 15, 2012)

Iustinian said:


> Technically -- we should all use two ropes according to ANSI; your work positioning/access line (depending on your climbing style) and an additional access line, in case the need for an aerial rescue arises -- makes for a faster safer rescue, assuming that you've performed an online test of the access line.
> 
> Sawyer is correct again -- WLL is a factor. Working Load Limit is generally accepted to be 10% of the maximum break strength, assumed that there are no structural defects in the line.
> 
> ...



Now I am learning something. Good info. Thanks


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## Carburetorless (Feb 15, 2012)

VA-Sawyer said:


> Clueless Carb,
> 
> What you said was a 180 degree bend made a rope 1/2 as strong. You didn't just say weaker, you said it loses 1/2 of its strength. Just page up and read your own BS ! Just curious, do you also put cement in tee cavities ?
> 
> Rick



Now you're splitting hairs; Stop being a keyboard jockey.


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## Carburetorless (Feb 15, 2012)

VA-Sawyer said:


> Wrong again CC. WLL means that you can put a 810 lb guy on the line and be safe. You need to understand that WLL includes a safety factor that puts the limit well below the breaking strength of the rope. I have to say that Clueless fits you to a T.
> 
> Rick



Bla, bla, bla bla bla.


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## Carburetorless (Feb 15, 2012)

sgreanbeans said:


> Dinked Carb for unsafe info.



You didn't dink me did you? Did you? Did you dink me? Seriously man; Did you dink me??


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## VA-Sawyer (Feb 15, 2012)

The point is splitting hairs can be the difference between living and not living.
You got dinked for spreading bad info, and that is why I started on your case to begin with.
You need to do more learning before you start trying to tell others how things are. I will be keeping on you every time you say something WRONG !
Rick


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## Carburetorless (Feb 15, 2012)

VA-Sawyer said:


> The point is splitting hairs can be the difference between living and not living.
> You got dinked for spreading bad info, and that is why I started on your case to begin with.
> You need to do more learning before you start trying to tell others how things are. I will be keeping on you every time you say something WRONG !
> Rick



Gosh, now I feel special. :msp_thumbup:

Anyway,

Since I'm a newb and all; What does "dinked" mean?


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## Carburetorless (Feb 15, 2012)

Del_ said:


> Palm of the hand to forehead.



You changed your reply. I'm glad I didn't reply before, that would have be awkward.


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## Carburetorless (Feb 15, 2012)

Del_ said:


> Giving out advice that has to be corrected would make most feel awkward.



I need to get one of those ignore list apps.


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## tree md (Feb 15, 2012)

Ignorance is bliss.


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