• The SH Membership has gone live. Only SH Members have access to post in the classifieds. All members can view the classifieds. Starting in 2020 only SH Members will be admitted to the annual hunting contest. Current members will need to follow these steps to upgrade: 1. Click on your username 2. Click on Account upgrades 3. Choose SH Member and purchase.
  • We've been working hard the past few weeks to come up with some big changes to our vendor policies to meet the changing needs of our community. Please see the new vendor rules here: Vendor Access Area Rules

prussic KN?

CharlieTN said:
Not to get into a debate, if each connection is holding roughly half then that would greatly decrease the chance of failure. Of course that assumes knots are tied correctly and checked often. So i would argue that it is a great benefit to have the double connection on a hitch like that. In addition, those hitches I listed are so much easier to work with in the majority of the applications we use over the actual prusik knot which tends to lock up tight as a drum.
Click to expand...

No you’re totally right. But say a guy tied one scaffold hitch to hook to his carabiner correctly and one incorrectly, he’s gonna fall. Meaning it would only take one strand of the 2 ended hitch breaking to induce a fall. So say on side of the hitch is slightly longer because the hitch isn’t dressed, and a static fall somehow causes the hitch cord to break, one strand will break before the other and no amount of ends will keep that from happening.

I realize this is all far fetched. I’m just attempting to state the fact that regardless of it being doubled, it only takes one end breaking to cause a fall, thus not doubling the breaking strength.


Sent from my iPhone using Tapatalk
 
WannaBMonkey said:
Where your caribiner hangs in the loop, it's one strand curved around the caribiner, so, I could be wrong, but I still believe that you only have the strength of one strand. The "two strands" are not independently supporting the load and not independently attached to where if one side breaks, the other still holds. I'm no engineer, but I'd like to hear some other's opinions on this. Like I said, I could be wrong. Anyone? Now I am truly curious. Not trying to start an argument, but I would really like a third opinion.

Sent from my XT1585 using Tapatalk
Click to expand...
Think of the carabiner acting like a pulley on the rope. The downward force at a pulley (carabiner) is twice the force that is applied in tension of the rope. This is what give you the 2:1 mechanical advantage of a pulley. The ultimate strength of the rope will decrease due to the sharp angle it takes through the carabiner, but the load that is applied to the rope at the carabiner will still only be 1/2 the total load at the carabiner.
 
Live4Now said:
Think of the carabiner acting like a pulley on the rope. The downward force at a pulley (carabiner) is twice the force that is applied in tension of the rope. This is what give you the 2:1 mechanical advantage of a pulley. The ultimate strength of the rope will decrease due to the sharp angle it takes through the carabiner, but the load that is applied to the rope at the carabiner will still only be 1/2 the total load at the carabiner.
Click to expand...
A single pulley doesn't give a 2:1 mechanical advantage. For one unit of measure of movement on the down side, you get one unit of measure of movement on the up side. Hence 1:1. Only by adding more pulleys (think block and tackle) do you get mechanical advantage.


Sent from my Z559DL using Tapatalk
 
WannaBMonkey said:
A single pulley doesn't give a 2:1 mechanical advantage. For one unit of measure of movement on the down side, you get one unit of measure of movement on the up side. Hence 1:1. Only by adding more pulleys (think block and tackle) do you get mechanical advantage.


Sent from my Z559DL using Tapatalk
Click to expand...
It occurred to me that this could be looked at in more than one way. I was looking at a load being on one end of the rope and force at other end with a pulley in the middle. However, if force is at one end and other end is static, with load at the pulley, you actually do get 2:1. That's how you were probably looking at it. So you just might be right. What a thought experiment this is turning into!

Sent from my Z559DL using Tapatalk
 
WannaBMonkey said:
It occurred to me that this could be looked at in more than one way. I was looking at a load being on one end of the rope and force at other end with a pulley in the middle. However, if force is at one end and other end is static, with load at the pulley, you actually do get 2:1. That's how you were probably looking at it. So you just might be right. What a thought experiment this is turning into!

Sent from my Z559DL using Tapatalk
Click to expand...
It depends on if you are the load. If so, your weight is distributed on the 2 lines and effectively becomes a 2:1 for you.

This caused me many head scratching moments and still does from time to time.
 
It could be avoided by tying into your climbing rope, and using your friction hitch as a progress capture or positioning device, as it was intended.
 
Not my picture, but something I’ve started doing for quick and cheap insurance is tying a figure 8 on a bight into the tag end of my tether and clipping that into my carabiner with my prusik. Basically the same as this picture, but with a prusik instead of a ropeman. No extra equipment needed.
2a8335a6a7fa7a002fea9e47069fa14e.jpg



Sent from my iPhone using Tapatalk
 
trailblazer75 said:
Right. But that is fouled thinking. It one of the connections somehow broke, the hitch cord would (COULD) simply come unwrapped and let you fall. So it does t actually pay to double it on a hitch like that.


Sent from my iPhone using Tapatalk
Click to expand...
Actually a lot of hitches will hold using only one leg, Michoacán is one, VT is one that won’t.
 
trailblazer75 said:
No you’re totally right. But say a guy tied one scaffold hitch to hook to his carabiner correctly and one incorrectly, he’s gonna fall. Meaning it would only take one strand of the 2 ended hitch breaking to induce a fall. So say on side of the hitch is slightly longer because the hitch isn’t dressed, and a static fall somehow causes the hitch cord to break, one strand will break before the other and no amount of ends will keep that from happening.

I realize this is all far fetched. I’m just attempting to state the fact that regardless of it being doubled, it only takes one end breaking to cause a fall, thus not doubling the breaking strength.


Sent from my iPhone using Tapatalk
Click to expand...
The are operator induced failures, not rope breakage or equipment failure.

it is an area where we absolutely need to make people aware of the dangers, and at the same time educate the newcomers on proper and safe ways to do what we do, but it’s also easy to get caught up in the “what if” to an extreme and unrealistic realm.

On a related note, I have noticed a whole lot of sloppy hitches and knot work in a lot of the photos. It would be good to emphasize the importance of dressing knots correctly, correctly tying and adjusting the hitches we use, and in general proper and safe rope management.

The issue with a weaker rope being used on a prusik knot is that all of the force is placed on that tight bend on the rope as it passes around the carabiner. Tight bends with ropes are always a cause for concern as the outer strands are stretched greatly. Any way we can mitigate that issue, either through stronger ropes (a common technique), different attachments (that don’t have as tight of a bend), or spreading out the load (such as the dual attachments of the Schwabisch/Distel hitches), we have done the best we can to negate or greatly reduce that concern.


We’re all in this together and these safety discussions, although viewed as boring and tedious by some, are very important. Hoping we all go home safely at the end of each hunt.
 
Red Beard said:
Do you have a picture of what you mean by this @kyler1945? Are you talking about an oops loop?
Click to expand...


I’m not a professional, but there’s little harm in me pointing out that for tree climbing, you should always be connected to rope/hardware that has a MBS of 5400lbs, according to this guide. Many of the friction hitches we use, don’t meet that minimum. For DRT, you’re always connected directly to your climbing rope. For SRT, you’re always attached with two mechanical ascenders. This brochure is very clear, and common sense dictates as well, if you’re to stop and perform work, or introduce slack, or the potential exists to introduce slack, you’ll need another positioning device or lanyard to do so. If you’re going to load either mechanical device alone without the other in place, another positing device or lanyard is needed.

crossing over to hunting - if you’re attaching your tether, and getting ready to get on your platform, you’re doing what is described above. If you’re just attached with a friction hitch, especially one rated below 5400lbs, you’re taking a large risk. The advice to wear your lineman’s during the transition is nice, but flawed. You SHOULD do that, but it does not offer protection Against a friction hitch failure. It offers BALANCE by giving you 3-4 points of contact so you can work hands free (one or both feet and each hip).

I don’t have a picture of what I’m describing, and I’m firmly in the camp of not showing what I do or giving advice on what others should do now, with specific regards to climbing techniques and equipment. There’s just too much bad information and bad reception of it. But I am comfortable sharing things I DON’T do. And I don’t hang from a single friction hitch or mechanical device at height. And I don’t hang from anything rated less than 5400lbs MBS.
 
I think it's also important to keep in mind the difference between stopping a fall and preventing it in the first place. There's a lot more force involved in stopping a fall and that's where equipment is most likely to fail. If you eliminate slack in your system as much as possible, your entire system is holding you rather than catching you. And you're a lot less likely to see the downright scary equipment failures like you see in the videos of stuff being ripped apart on test stands. Those tests are subjecting equipment to forces it should never experience when used properly. Take a little extra time to really think about what you are doing and avoid leaving yourself open to a potentially dangerous situation in the first place. Yeah you want your setup to be able to withstand an accidental fall. But I for one don't really want to put it to the ultimate test.

Sent from my Z559DL using Tapatalk
 
kyler1945 said:

I’m not a professional, but there’s little harm in me pointing out that for tree climbing, you should always be connected to rope/hardware that has a MBS of 5400lbs, according to this guide. Many of the friction hitches we use, don’t meet that minimum. For DRT, you’re always connected directly to your climbing rope. For SRT, you’re always attached with two mechanical ascenders. This brochure is very clear, and common sense dictates as well, if you’re to stop and perform work, or introduce slack, or the potential exists to introduce slack, you’ll need another positioning device or lanyard to do so. If you’re going to load either mechanical device alone without the other in place, another positing device or lanyard is needed.

crossing over to hunting - if you’re attaching your tether, and getting ready to get on your platform, you’re doing what is described above. If you’re just attached with a friction hitch, especially one rated below 5400lbs, you’re taking a large risk. The advice to wear your lineman’s during the transition is nice, but flawed. You SHOULD do that, but it does not offer protection Against a friction hitch failure. It offers BALANCE by giving you 3-4 points of contact so you can work hands free (one or both feet and each hip).

I don’t have a picture of what I’m describing, and I’m firmly in the camp of not showing what I do or giving advice on what others should do now, with specific regards to climbing techniques and equipment. There’s just too much bad information and bad reception of it. But I am comfortable sharing things I DON’T do. And I don’t hang from a single friction hitch or mechanical device at height. And I don’t hang from anything rated less than 5400lbs MBS.
Click to expand...
Just to be contrarian, that guide actually clearly endorses climbing trees with no safety lanyard at all, as long as the bole is at least 4in in diameter at/below your height.
 
Last edited:
kyler1945 said:

I’m not a professional, but there’s little harm in me pointing out that for tree climbing, you should always be connected to rope/hardware that has a MBS of 5400lbs, according to this guide. Many of the friction hitches we use, don’t meet that minimum. For DRT, you’re always connected directly to your climbing rope. For SRT, you’re always attached with two mechanical ascenders. This brochure is very clear, and common sense dictates as well, if you’re to stop and perform work, or introduce slack, or the potential exists to introduce slack, you’ll need another positioning device or lanyard to do so. If you’re going to load either mechanical device alone without the other in place, another positing device or lanyard is needed.

crossing over to hunting - if you’re attaching your tether, and getting ready to get on your platform, you’re doing what is described above. If you’re just attached with a friction hitch, especially one rated below 5400lbs, you’re taking a large risk. The advice to wear your lineman’s during the transition is nice, but flawed. You SHOULD do that, but it does not offer protection Against a friction hitch failure. It offers BALANCE by giving you 3-4 points of contact so you can work hands free (one or both feet and each hip).

I don’t have a picture of what I’m describing, and I’m firmly in the camp of not showing what I do or giving advice on what others should do now, with specific regards to climbing techniques and equipment. There’s just too much bad information and bad reception of it. But I am comfortable sharing things I DON’T do. And I don’t hang from a single friction hitch or mechanical device at height. And I don’t hang from anything rated less than 5400lbs MBS.
Click to expand...
I think you someone how convinced me to tie into my tether from here on out and use the friction hitch to set my height... hmm this is a first
 
gcr0003 said:
I think you someone how convinced me to tie into my tether from here on out and use the friction hitch to set my height... hmm this is a first
Click to expand...

I have a figure 8 on a bight at the end of my tether and this is clipped back into my carabiner. Also, once I set my tether length, I tie multiple overhands on a bight on the tag between the hitch and that terminating figure 8 that is clipped. I usually tie 3 of these overhands to act as a stopper knot if my hitch slides (they are easy to tie without disconnecting my figure 8 from the carabiner and I can't see my hitch untying 3 of them...that said those overhands probably aren't the proper knot there).

So, I'm considering clipping my top overhand on a bight stopper knot back to the carabiner.
 
mattsteg said:
Just to be contrarian, that guide actually clearly endorses climbing trees with no safety lanyard at all, as long as the bole is at least 4in in diameter at/below your height.
Click to expand...

most people hunting today, with the exception of those who climb rope, use a lifeline(but they had to install the lifeline), or advance their tether from ground level up, free climb. The brochure states that in order to free climb, one must use 3 point climbing. Two of these points can be your lineman’s connection.

I won’t really get into what I do when I climb, but what I DON’T do is ever have less than three points of contact, without being connected to the tree with equipment rated at no less than 5400lbs mbs.
 
Oh
raisins said:
I have a figure 8 on a bight at the end of my tether and this is clipped back into my carabiner. Also, once I set my tether length, I tie multiple overhands on a bight on the tag between the hitch and that terminating figure 8 that is clipped. I usually tie 3 of these overhands to act as a stopper knot if my hitch slides (they are easy to tie without disconnecting my figure 8 from the carabiner and I can't see my hitch untying 3 of them...that said those overhands probably aren't the proper knot there).

So, I'm considering clipping my top overhand on a bight stopper knot back to the carabiner.
Click to expand...
Oh wait yea I already do this... Nevermind. I just need to start doing this while one sticking. I have been waiting to get to hunting height and then running the figure 8 back to the carabiner but I need to do that as soon as I leave the ground.
 
CharlieTN said:
The are operator induced failures, not rope breakage or equipment failure.

it is an area where we absolutely need to make people aware of the dangers, and at the same time educate the newcomers on proper and safe ways to do what we do, but it’s also easy to get caught up in the “what if” to an extreme and unrealistic realm.

On a related note, I have noticed a whole lot of sloppy hitches and knot work in a lot of the photos. It would be good to emphasize the importance of dressing knots correctly, correctly tying and adjusting the hitches we use, and in general proper and safe rope management.

The issue with a weaker rope being used on a prusik knot is that all of the force is placed on that tight bend on the rope as it passes around the carabiner. Tight bends with ropes are always a cause for concern as the outer strands are stretched greatly. Any way we can mitigate that issue, either through stronger ropes (a common technique), different attachments (that don’t have as tight of a bend), or spreading out the load (such as the dual attachments of the Schwabisch/Distel hitches), we have done the best we can to negate or greatly reduce that concern.


We’re all in this together and these safety discussions, although viewed as boring and tedious by some, are very important. Hoping we all go home safely at the end of each hunt.
Click to expand...

easy solution to mitigate tight radius caused by a carabiner. use 2 carabiners and boom, tight radius mitigated. to some degree... and all the things you said too.
 
You must log in or register to reply here.
Back
Top