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Carabiner or quick link for tether attachment??

gcr0003 said:
This sounds like you’re saying it’s unsafe or somehow less safe to climb or hang on static rope.

I think what you’re trying to say is there is more risk falling on slack static rope such as what presents itself during one-sticking. I think it’s worth distinguishing the two. There are reasons that arborist climb static rope. The difference dynamic rope is going to make on a short tether fall is negligible and shouldn’t be pushed as gospel over the risks of using dynamic rope. Dynamic rope has its own pros and cons and should be used carefully as well.
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@gcr0003 for president!
 
gcr0003 said:
This sounds like you’re saying it’s unsafe or somehow less safe to climb or hang on static rope.

I think what you’re trying to say is there is more risk falling on slack static rope such as what presents itself during one-sticking. I think it’s worth distinguishing the two. There are reasons that arborist climb static rope. The difference dynamic rope is going to make on a short tether fall is negligible and shouldn’t be pushed as gospel over the risks of using dynamic rope. Dynamic rope has its own pros and cons and should be used carefully as well.
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i hate to keep beating this drum, but the idea that short falls won't be helped by dynamic line is just asserted here and i think is counter to science and is based upon our gut/what folks say around here

but our gut is a horrible device for figuring out what happens over short distances and microseconds because we never observe this in everyday life (can't see it) in order to build our intuition for it (sorta like super high temps and pressures....they surprise people for this reason)

sure, you don't get those big bounces like on 100 feet of dynamic line

but why is it better to fall and hit your head on grass/dirt versus concrete (actually way better)? it's because the turf is 'softer'....why is it softer? because it gives like 1 inch

1 or 2 inches of give is way (like incalculably) better than 0 inches of give

try hanging on a dynamic tether, if you haven't, and bounce around on it....that it will help you will be obvious
 
raisins said:
i hate to keep beating this drum, but the idea that short falls won't be helped by dynamic line is just asserted here and i think is counter to science and is based upon our gut/what folks say around here

but our gut is a horrible device for figuring out what happens over short distances and microseconds because we never observe this in everyday life (can't see it) in order to build our intuition for it (sorta like super high temps and pressures....they surprise people for this reason)

sure, you don't get those big bounces like on 100 feet of dynamic line

but why is it better to fall and hit your head on grass/dirt versus concrete (actually way better)? it's because the turf is 'softer'....why is it softer? because it gives like 1 inch

1 or 2 inches of give is way (like incalculably) better than 0 inches of give

try hanging on a dynamic tether, if you haven't, and bounce around on it....that it will help you will be obvious
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Not what I said at all. I said it is negligible on short tethers. Negligible doesn’t mean that it wouldn’t help at all, it just means that it won’t help you that much. This would be dependent on weight, amount of slack, distance of fall, direction of fall, elongation of each rope, how the rope is attached, type of attachment method etc. All of which can be calculated and have been calculated. Before you ask, no I’m not sharing my own calculations because like everything said on this website there are pros and cons and you have to take the responsible for that yourself.

This opinion isn’t my gut feeling. This isn’t fairytale land, all of this can be tested, calculated and proven. Until you do the math or the test to prove otherwise you point is mute.

The dynamic tether advocates (like many things on saddlehunter) continue to hype benefits while disregarding or failing to mention downsides or risks. I wasn’t advocating for either, I simply said they each have pros and cons. That’s why I think it’s lame to come on here and safe shame people based on no data and without talking about other risks. And simply saying dynamic tethers are safer is the biggest gut feeling response there is. Why is it safer? Quantify why it is safer or provided data that suggests otherwise, otherwise it’s just your unsupported opinion. And No, bouncing around on a short tether as a justification for it being safer to fall 4 ft from is not doing it for me.

This is a lot chirpier than I like to be over text forums but I felt called out on your reply haha
 
gcr0003 said:
Not what I said at all. I said it is negligible on short tethers. Negligible doesn’t mean that it wouldn’t help at all, it just means that it won’t help you that much. This would be dependent on weight, amount of slack, distance of fall, direction of fall, elongation of each rope, how the rope is attached, type of attachment method etc. All of which can be calculated and have been calculated. Before you ask, no I’m not sharing my own calculations because like everything said on this website there are pros and cons and you have to take the responsible for that yourself.

This opinion isn’t my gut feeling. This isn’t fairytale land, all of this can be tested, calculated and proven. Until you do the math or the test to prove otherwise you point is mute.

The dynamic tether advocates (like many things on saddlehunter) continue to hype benefits while disregarding or failing to mention downsides or risks. I wasn’t advocating for either, I simply said they each have pros and cons. That’s why I think it’s lame to come on here and safe shame people based on no data and without talking about other risks. And simply saying dynamic tethers are safer is the biggest gut feeling response there is. Why is it safer? Quantify why it is safer or provided data that suggests otherwise, otherwise it’s just your unsupported opinion. And No, bouncing around on a short tether as a justification for it being safer to fall 4 ft from is not doing it for me.

This is a lot chirpier than I like to be over text forums but I felt called out on your reply haha
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sorry if I rubbed you the wrong way, I don't think I shamed anyone

I don't think it is fair not to share your reasoning with others that might read this and be influenced by it. I'll share my calculations here.

I'm not a physicist but I did teach a general science course for 5 years with a physics section and labs (which included drop experiments, impact, projectile motion) and I really enjoyed that and spent a lot of time on mine own studying Newtonian physics.

Of course, this is a simplification, but I believe it is an accurate one. I won't use real numbers but variables and will focus on percent reduction in force and not absolute reduction. After a certain % reduction, you might very well still get hurt or die, but I'll take a certain discount.

Falling under the force of gravity accelerates you at around 9.8 m/s/s

Your kinetic energy as a result of the fall will be KE = 1/2 * mass * velocity squared (velocity a result of gravity and time falling, of course)

The work that the rope has to do to slow you down is equal to that KE and is

Work = mass x acceleration x distance

The work is a function of your mass and fall time and so can be taken as a constant, it does not change no matter what is going on with the rope

Your mass is constant

The acceleration is the rope decelerating your body and the lower the number the better for you

Distance is the amount of rope stretch, with a stretchy rope decelerating you over a longer distance

We can rearrange the Work equation to

Work/(mass*distance) = acceleration

let's throw in a number of 1 (units don't matter here) and then 2 for rope stretch (distance over which the deceleration (negative acceleration) occurs)

Work/(mass x 1) is twice work/(mass x 2)

since (work/(mass x 1))/(work/(mass x 2)) = 2

So, the rope that stretches a unit of 1 will have twice the deceleration as a rope that stretches 2 units

The units here don't matter if we focus on the percentage change

A rope that stretches 2 inches will have half the deceleration from the rope as a rope that stretches 1 inch (this could also be 2 feet and 1 feet....it is still half with the 2 feet of stretch vs 1 foot).....this translates into half the instantaneous force since mass is constant and force = mass x acceleration

That's why the concrete vs grass example works, and not just for falls from standing height

There are a decent number of cases (I even know someone that observed this in the military) of people falling from planes (chute didn't open) and they landed in a field and survived.....I've never heard this happen on concrete......it might be possible to hit concrete and live but (although both are rare), I'd say the grass field is way, way more likely

When viewed this way, I don't think you have to include many other complicating factors.
 
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raisins said:
sorry if I rubbed you the wrong way, I don't think I shamed anyone

I don't think it is fair not to share your reasoning with others that might read this and be influenced by it. I'll share my calculations here.

I'm not a physicist but I did teach a general science course for 5 years with a physics section and labs (which included drop experiments, impact, projectile motion) and I really enjoyed that and spent a lot of time on mine own studying Newtonian physics.

Of course, this is a simplification, but I believe it is an accurate one. I won't use real numbers but variables and will focus on percent reduction in force and not absolute reduction. After a certain % reduction, you might very well still get hurt or die, but I'll take a certain discount.

Falling under the force of gravity accelerates you at around 9.8 m/s/s

Your kinetic energy as a result of the fall will be KE = 1/2 * mass * velocity squared

The work that the rope has to do to slow you down is equal to that KE and is

Work = mass x acceleration x distance

The work is a function of your mass and fall time and so can be taken as a constant, it does not change no matter what is going on with the rope

Your mass is constant

The acceleration is the rope decelerating your body and the lower the number the better for you

Distance is the amount of rope stretch, with a stretchy rope decelerating you over a longer distance

We can rearrange the Work equation to

Work/(mass*distance) = acceleration

let's throw in a number of 1 (units don't matter here) and then 2 for rope stretch (distance over which the deceleration (negative acceleration) occurs)

Work/(mass x 1) is twice work/(mass x 2)

since (work/(mass x 1))/(work/(mass x 2)) = 2

So, the rope that stretches a unit of 1 will have twice the deceleration as a rope that stretches 2 units

The units here don't matter if we focus on the percentage change

A rope that stretches 2 inches will have half the deceleration from the rope as a rope that stretches 1 inch (this could also be 2 feet and 1 feet....it is still half with the 2 feet of stretch vs 1 foot).....this translates into half the instantaneous force since mass is constant and force = mass x acceleration

That's why the concrete vs grass example works, and not just for falls from standing height

There are a decent number of cases (I even know someone that observed this in the military) of people falling from planes (chute didn't open) and they landed in a field and survived.....I've never heard this happen on concrete......it might be possible to hit concrete and live but (although both are rare), I'd say the grass field is way, way more likely

When viewed this way, I don't think you have to include many other complicating factors.
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Im sorry but that hodgepodge of pseudo-physics equations applied in that way is not accurate.

At the highest level you can go. You need calculate or test (testing would probably be easier) how much the stretch in the dynamic rope will decrease the acceleration of body falling, and the resulting force. Then you would need to quantify in some way how much safer the difference in lbf to the body would be over the static rope.

Then, taking in consideration the delta in forces transferred to the body, take into account the other risks that are inherent with dynamic rope and make a full assessment of which you consider to be more safe.

But even that simplified force to force comparison doesn’t take into consideration the friction hitches and their ability or lack thereof to decelerate. So really you got to just test this stuff out. If I get a chance to at work I will one day.
 
Elongation % is a function of the rope length. That’s why on shorter ropes the stretch is less.

What length falls are you thinking this is going to be safer for? 2ft, 4ft, 6ft?
 
gcr0003 said:
Im sorry but that hodgepodge of pseudo-physics equations applied in that way is not accurate.

At the highest level you can go. You need calculate or test (testing would probably be easier) how much the stretch in the dynamic rope will decrease the acceleration of body falling, and the resulting force. Then you would need to quantify in some way how much safer the difference in lbf to the body would be over the static rope.

Then, taking in consideration the delta in forces transferred to the body, take into account the other risks that are inherent with dynamic rope and make a full assessment of which you consider to be more safe.

But even that simplified force to force comparison doesn’t take into consideration the friction hitches and their ability or lack thereof to decelerate. So really you got to just test this stuff out. If I get a chance to at work I will one day.
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nothing pseudo about that, those are all the relevant beginning equations to consider

those are the basic ways a physicist would first approach this problem, i believe

you can't argue with twice the stretch decreasing deceleration in half....it just is...and is one of those cases where intuition works pretty well

i'm not conducting a master's thesis on this complete with dynamic simulations, and it isn't fair for someone to stand back and assert i'm wrong and they are right until i do (when they aren't either)

but i put something out there (which makes sense, but admittedly does not take into account every possible thing)....you didn't.....which i think you think puts you at an advantage

but i'll leave that for others to decide

i put out coherent reasoning, and you just say it is wrong, throw some things i admittedly left out, but you aren't sharing anything tangible for a similar critique

you're usually a pretty nice and reasonable person...but now you aren't acting like that

which makes me conclude that i am 'over the target'
 
gcr0003 said:
Elongation % is a function of the rope length. That’s why on shorter ropes the stretch is less.

What length falls are you thinking this is going to be safer for? 2ft, 4ft, 6ft?
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i agree that a longer rope stretches more

but my previous post takes that into account

my edelrid rope has a 33% elongation

let's cut that in half for the sake of argument and say we are using 4 feet of rope (around tree plus what is hanging off)

so 48 inches/6 = 8 inches of stretch

that isn't the bouncy house effect you see on big wall climbs, but it is way better (in fact around 8 times better) than 1 inch of stretch
 
raisins said:
i agree that a longer rope stretches more

but my previous post takes that into account

my edelrid rope has a 33% elongation

let's cut that in half for the sake of argument and say we are using 4 feet of rope (around tree plus what is hanging off)

so 48 inches/6 = 8 inches of stretch

that isn't the bouncy house effect you see on big wall climbs, but it is way better (in fact around 8 times better) than 1 inch of stretch
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What I’m trying to do is encourage people to stop saying something is better or safer, especially without acknowledging all the risks.
 
JC3 said:
This is a triple locking carabiner that I have used many, many times, for ascent and decent with no adverse effect.
It is not much bigger than the screw locking link.
The angled pin keeps the carabiner oriented correctly.
View attachment 68243
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You don't want to side load a carabiner which can be done that's why the manufacturer warns against doing it.
 
John RB said:
I would like to nominate @Spartan for president.... pls read what he wrote. It's pure wisdom and could save a lot of bones.

I will add to it: we have a majority of saddle hunters climbing with NO tie in. And a lot of folks think their Lineman's belt will prevent an injury or fall and it CAN'T do so. A tie in needs to be cinched and secure. Slack needs to be zero or measured in inches, not feet. A Ropeman can become a knife if ya fall on it. I have given ya the JRB Hitch and the Saddle Hunter's Hitch and the JRB Cinch as 3 other options as well. Don't care what ya use, but please use something. If ya need to leave something home, make it the Lineman's belt. Don't do it for you, do it for the people who expect you in a chair instead of a wheelchair at Thanksgiving dinner. I have heard and seen too much in my days, so please pardon my attitude.

Sent from my SM-G975U using Tapatalk
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John I am sorry but I disagree on your assessment on leaving your lineman’s rope at home. It is the only reason my “fall” last season on the helium sticks was only about 14 to 18” and not 14’ to the ground. We can debate if you’d like, but these are trees not poles, most guys using lineman’s ropes are using climbing sticks, and the reward of using the lineman’s rope (properly tensioned and positioned of course) far outweighs the risk of not using it.
 
Fl Canopy Stalker said:
John I am sorry but I disagree on your assessment on leaving your lineman’s rope at home. It is the only reason my “fall” last season on the helium sticks was only about 14 to 18” and not 14’ to the ground. We can debate if you’d like, but these are trees not poles, most guys using lineman’s ropes are using climbing sticks, and the reward of using the lineman’s rope (properly tensioned and positioned of course) far outweighs the risk of not using it.
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Don't mistake my intent. I am saying Don't spend a second in a tree without a tether or climbing rope with little or no slack. Yes, a lineman's can prevent an injury but ya can't count on it. I am saying that most falls are preventable. Ya cant fall if you're tied in. So tie in. The whole way. Then you can use a lineman's if ya like, but as a positioning device, not a fall arrest device.

Sent from my SM-G975U using Tapatalk
 
John RB said:
Don't mistake my intent. I am saying Don't spend a second in a tree without a tether or climbing rope with little or no slack. Yes, a lineman's can prevent an injury but ya can't count on it. I am saying that most falls are preventable. Ya cant fall if you're tied in. So tie in. The whole way. Then you can use a lineman's if ya like, but as a positioning device, not a fall arrest device.

Sent from my SM-G975U using Tapatalk
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I agree with it not being better than being tied off but a lineman’s rope kept under tension and at the correct height above the connection point, is work positioning. Of course you could always make a poor man’s tree squeeze using an extra tether prusik and carabiner and you would be unable to fall as well…. Saddles aren’t fall arrest devices. I just wanted to clear the air since your statement was lineman’s ropes cannot prevent a fall and that is not completely true. Great advice otherwise
 
raisins said:
pretty slick....what are you using to the right to capture the rope....is it easily moved to the side to fish the rope out to go around branches?

do you hang from that at height during the hunt or just use when climbing or rappeling?
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Brocky doesn’t hunt yet, I think he use to do arborist work and still rec climbs but is just here to learn us a thing or two! What is that carabiner?
 
gcr0003 said:

30mm carabiner

ZICRAL 30mm self-locking automatic carabiner
www.gingliders.com www.gingliders.com

Funky shape for sure
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interesting warning that i've posted here about aluminum (makes me think maybe a steel biner on your tether to bridge connection might be a good idea as well as a steel quick link around tree)

isn't it true that even at low loads that loading and unloading an aluminum carabiner over and over will eventually make it fail whereas steel doesn't have this property? (with steel, if you are below a certain loading....then cycles of loading and unloading and hanging from it does not eventually lead to failture)

CAUTION

Automatic aluminium carabiners have a limited lifetime due to metal fatigue. They must be replaced after 5 years or 500 flight hours, whichever is soonest. They should never be used between spreaders and tandem wing risers as main carabiners. They should also never be used to connect rescue systems.
 
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