- Location
- Melbourne, Victoria, Australia.
Re: Petzl Dual Ascender Build
Brilliant analogy there TM, thanks for the time it took to do that!
Brilliant analogy there TM, thanks for the time it took to do that!
dual petzel ascensions
- Thread starter Colin
- Start date
Re: Dual Petzl Ascensions
[ QUOTE ]
There's pure positive in a single device that will work with you on the up and the down. But usually there's a tradeoff.
[/ QUOTE ]
There is no trade off with the Unicender. It goes up with no friction because the smooth cams flex and fully release from the rope.
For the rare times 2:1 movement is required a rads pulley like the one pictured in the attachment can be used. It performs downward transitions smoothly for small adjustments but is also capable of long fast descents. It does not need a doubled rope to function so allows true SRT advantages such as faster line setting over multiple limbs so the TIP (a common point of failure) is backed up. Simple redirects that are not hampered by friction.
A doubled line that can function in a 2:1 mode is not in any way redundant because failure of one line or cam produces full system failure.
Dave
[ QUOTE ]
There's pure positive in a single device that will work with you on the up and the down. But usually there's a tradeoff.
[/ QUOTE ]
There is no trade off with the Unicender. It goes up with no friction because the smooth cams flex and fully release from the rope.
For the rare times 2:1 movement is required a rads pulley like the one pictured in the attachment can be used. It performs downward transitions smoothly for small adjustments but is also capable of long fast descents. It does not need a doubled rope to function so allows true SRT advantages such as faster line setting over multiple limbs so the TIP (a common point of failure) is backed up. Simple redirects that are not hampered by friction.
A doubled line that can function in a 2:1 mode is not in any way redundant because failure of one line or cam produces full system failure.
Dave
Attachments
- Location
- Central Hardwood Belt, USA
Re: Dual Petzl Ascensions
Thanks DSMc. I've not seen the pulley affixed to the bottom hole. I love gear that multi-functions! I've caribined on a micropully when needed, but never thought to have something installed. I think that's cool. I can envision the rope passing through the ascender shell/cam, around the lower pulley, back up to a second pulley anchored to the top hole. This is not a RADS, but rather more like a dual, inline Z-shaped redirect in a small space, no change in mechanical advantage, but increased friction, especially if the upper pulley was eliminated altogether and the rope run through a triple-lockbiner, or the bottom pulley was not actually a pulley, but a mini bollard. I suppose you could descend 1:1 SRT with by just releasing the cam in accordance with the published instructions given by Petzl, and a simple hand belay at that point, worthy of giving it a try to see if it performs.
I doubt you were intending for your innovation to be turned into a descent device, but when you say 3:1, I assume lifting, hauling or..... anything but ascent. 2:1 is plenty inefficient for ascent. 3:1, a magnitude worse. Novel in concept but not so practical in practice.
Thanks DSMc. I've not seen the pulley affixed to the bottom hole. I love gear that multi-functions! I've caribined on a micropully when needed, but never thought to have something installed. I think that's cool. I can envision the rope passing through the ascender shell/cam, around the lower pulley, back up to a second pulley anchored to the top hole. This is not a RADS, but rather more like a dual, inline Z-shaped redirect in a small space, no change in mechanical advantage, but increased friction, especially if the upper pulley was eliminated altogether and the rope run through a triple-lockbiner, or the bottom pulley was not actually a pulley, but a mini bollard. I suppose you could descend 1:1 SRT with by just releasing the cam in accordance with the published instructions given by Petzl, and a simple hand belay at that point, worthy of giving it a try to see if it performs.
I doubt you were intending for your innovation to be turned into a descent device, but when you say 3:1, I assume lifting, hauling or..... anything but ascent. 2:1 is plenty inefficient for ascent. 3:1, a magnitude worse. Novel in concept but not so practical in practice.
- Location
- Central Hardwood Belt, USA
Re: Dual Petzl Ascensions
[ QUOTE ]
A doubled line that can function in a 2:1 mode is not in any way redundant because failure of one line or cam produces full system failure.
[/ QUOTE ]
In hearing the word 'redundant' are you referencing my statement of earlier? [ QUOTE ]
I feel like 'downward adjustment of the ascender' is where guys get blurry. But that's what dually redundant, onboard, self-backing safety features now allow you to....
[/ QUOTE ]
This doesn't refer to a doubled line (or any line), whether 1:1 or 2:1. The dually redundant backup I'm speaking of are features on the ascender itself. This critical difference is what separates the Kong Trender and the Petzl Single Handled dual from all others and allows you certain simple freedoms that would otherwise be considered dicey or unacceptable practice.
I would like to share this in detail. It is a major (though simple) point and it's important that we understand the 'why' of why it's critical and why it works in a practical sense. Not asking for agreement, but rather clarity. You can contest the physics by yourself.
I expect guys to be judgmental and highly critical, and that's OK, as long as you're working with the correct information.
I'll start with the Kong Trender, what makes this unique dual ascender different and why it can be part of this new generation family of ascenders.
[ QUOTE ]
A doubled line that can function in a 2:1 mode is not in any way redundant because failure of one line or cam produces full system failure.
[/ QUOTE ]
In hearing the word 'redundant' are you referencing my statement of earlier? [ QUOTE ]
I feel like 'downward adjustment of the ascender' is where guys get blurry. But that's what dually redundant, onboard, self-backing safety features now allow you to....
[/ QUOTE ]
This doesn't refer to a doubled line (or any line), whether 1:1 or 2:1. The dually redundant backup I'm speaking of are features on the ascender itself. This critical difference is what separates the Kong Trender and the Petzl Single Handled dual from all others and allows you certain simple freedoms that would otherwise be considered dicey or unacceptable practice.
I would like to share this in detail. It is a major (though simple) point and it's important that we understand the 'why' of why it's critical and why it works in a practical sense. Not asking for agreement, but rather clarity. You can contest the physics by yourself.
I expect guys to be judgmental and highly critical, and that's OK, as long as you're working with the correct information.
I'll start with the Kong Trender, what makes this unique dual ascender different and why it can be part of this new generation family of ascenders.
- Location
- Central Hardwood Belt, USA
Re: Dual Petzl Ascensions
After climbing on these for one day, I took a pen and outlined where I may some day cut the second handle, but as yet have not. That was more because I didn't want to face the flame-fest that could come of that, not because I didn't think it wouldn't make a better performing ascender.
As for now, we'll keep it how it is, and comb over it, based on it's own merit and not the modifications we impart.
After climbing on these for one day, I took a pen and outlined where I may some day cut the second handle, but as yet have not. That was more because I didn't want to face the flame-fest that could come of that, not because I didn't think it wouldn't make a better performing ascender.
As for now, we'll keep it how it is, and comb over it, based on it's own merit and not the modifications we impart.
Attachments
- Location
- Central Hardwood Belt, USA
- Location
- Central Hardwood Belt, USA
- Location
- Central Hardwood Belt, USA
Re: Dual Petzl Ascensions
Closed.......
...... and open.
See that little protruding tab in the mini-biner hole? I have to remark on their design, one can not use the ascender with the captive plate held 'open' by the mini biner by someone so inclined to do that. The system almost requires that you employ the dual redundancy features, just to be able to climb on them, and the features themselves don't get in the way of the performance of the ascender(s), making compliance in using the onboard safety features more assured. The captive plate engages automatically after the rope is installed. All you do is positively secure it by inserting a mini biner in a hole. Nice. More dummy-proof, some might say.
In the ones we'll be making, coming up, the dual redundancy in not internal as here with the Kongs, but attached where one, or the other can be used independent of the another, so you have to tell the ascender what you want, rather than the ascender telling you what it requires.
The tradeoff of one additional motion (~2 seconds) is having the nice, meaty single handle, and the performance that is uniquely awesome to the Dual Petzl Ascensions, two motions to employ dual redundant safeties backing one another up, rather than just clipping in a mini biner on the Kong to employ the integrated safety features. Kong has it really boiled down. However, as I'll share upcoming, the Petzl matches or exceeds performance in all other respects, except for fine, polished appearance.
Performance over looks any day, thank you very much.
Closed.......
...... and open.
See that little protruding tab in the mini-biner hole? I have to remark on their design, one can not use the ascender with the captive plate held 'open' by the mini biner by someone so inclined to do that. The system almost requires that you employ the dual redundancy features, just to be able to climb on them, and the features themselves don't get in the way of the performance of the ascender(s), making compliance in using the onboard safety features more assured. The captive plate engages automatically after the rope is installed. All you do is positively secure it by inserting a mini biner in a hole. Nice. More dummy-proof, some might say.
In the ones we'll be making, coming up, the dual redundancy in not internal as here with the Kongs, but attached where one, or the other can be used independent of the another, so you have to tell the ascender what you want, rather than the ascender telling you what it requires.
The tradeoff of one additional motion (~2 seconds) is having the nice, meaty single handle, and the performance that is uniquely awesome to the Dual Petzl Ascensions, two motions to employ dual redundant safeties backing one another up, rather than just clipping in a mini biner on the Kong to employ the integrated safety features. Kong has it really boiled down. However, as I'll share upcoming, the Petzl matches or exceeds performance in all other respects, except for fine, polished appearance.
Performance over looks any day, thank you very much.
Attachments
Re: Dual Petzl Ascensions
[ QUOTE ]
[ QUOTE ]
A doubled line that can function in a 2:1 mode is not in any way redundant because failure of one line or cam produces full system failure.
[/ QUOTE ]
This doesn't refer to a doubled line (or any line), whether 1:1 or 2:1. The dually redundant backup I'm speaking of are features on the ascender itself. This critical difference is what separates the Kong Trender and the Petzl Single Handled dual from all others and allows you certain simple freedoms that would otherwise be considered dicey or unacceptable practice.
[/ QUOTE ]
Thanks for clearly stating that TM. You know that and many others do as well but it is commonly misunderstood. Many will not use a single line based on this false idea.
Dave
[ QUOTE ]
[ QUOTE ]
A doubled line that can function in a 2:1 mode is not in any way redundant because failure of one line or cam produces full system failure.
[/ QUOTE ]
This doesn't refer to a doubled line (or any line), whether 1:1 or 2:1. The dually redundant backup I'm speaking of are features on the ascender itself. This critical difference is what separates the Kong Trender and the Petzl Single Handled dual from all others and allows you certain simple freedoms that would otherwise be considered dicey or unacceptable practice.
[/ QUOTE ]
Thanks for clearly stating that TM. You know that and many others do as well but it is commonly misunderstood. Many will not use a single line based on this false idea.
Dave
- Location
- Central Hardwood Belt, USA
Re: Dual Petzl Ascensions
Yea, that IS a common misconception of single line.
Dually redundant, onboard safety features on an ascender will never save you from a failure of a line (a cut-through), but it will GREATLY reduce the already rare potential of a cam failing, down to a minimal possibility, seemingly remote to the point of, well, being able to trust it with your life. If a cam were to fail, or lodge open for whatever reason, the ascender takes it upon itself to at least make it so that the rope CAN NOT POSSIBLY ESCAPE THE ASCENDER SHELL. I capitalize that statement because, at the heart of it, this is the essence of the safeties; keep cams from being able to open fully, keep rope from, being able to escape the ascender shell.
Good reply, Dave. That's why I'm going to great lengths to be clear, not because I'm promoting anything, but just so that accurate information can be laid on the table for all to see. It's not the issue whether you use these things or not, but rather if you may someday give them a try we will all be working from the same platform of understanding.
Yea, that IS a common misconception of single line.
Dually redundant, onboard safety features on an ascender will never save you from a failure of a line (a cut-through), but it will GREATLY reduce the already rare potential of a cam failing, down to a minimal possibility, seemingly remote to the point of, well, being able to trust it with your life. If a cam were to fail, or lodge open for whatever reason, the ascender takes it upon itself to at least make it so that the rope CAN NOT POSSIBLY ESCAPE THE ASCENDER SHELL. I capitalize that statement because, at the heart of it, this is the essence of the safeties; keep cams from being able to open fully, keep rope from, being able to escape the ascender shell.
Good reply, Dave. That's why I'm going to great lengths to be clear, not because I'm promoting anything, but just so that accurate information can be laid on the table for all to see. It's not the issue whether you use these things or not, but rather if you may someday give them a try we will all be working from the same platform of understanding.
- Location
- Chattanooga
Re: Petzl Dual Ascender Build
Just some comments if I may. There are two SRT systems that I'm aware of that allow up and down without change-overs or gear removal from the line.
One is a Unicender based SRT and the other is a RADS SRT. I have not tried a Unicender yet, but I use a RADS all the time. The main advantage I see to the Unicender is it can be used in a rope walker configuration for long ascents if you add appropriate gear to the Unicender.
As for an emergency escape, if the RADS is setup properly, escape is just a matter of pulling the handle on the Grigri, Cinch, I'D, or Rig which ever you use.
For the Unicender, an emergency escape can be as simple as a RADS IF, again if it is setup properly, AND you are not in a rope walker configuration. The rope walker configuration would require some gear removal before a fast descent could be realized.
Other than the Unicender rope walker configuration, a properly set up RADS is about as effective as the Unicender and has the advantage of having a 3:1 MA for the arms to permit ascents without messing with footloops once you get in the tree.
And it should be stated that the Unicender can be setup in a RADS configuration, but it's not quite as clean as a Grigri based RADS.
Just some comments if I may. There are two SRT systems that I'm aware of that allow up and down without change-overs or gear removal from the line.
One is a Unicender based SRT and the other is a RADS SRT. I have not tried a Unicender yet, but I use a RADS all the time. The main advantage I see to the Unicender is it can be used in a rope walker configuration for long ascents if you add appropriate gear to the Unicender.
As for an emergency escape, if the RADS is setup properly, escape is just a matter of pulling the handle on the Grigri, Cinch, I'D, or Rig which ever you use.
For the Unicender, an emergency escape can be as simple as a RADS IF, again if it is setup properly, AND you are not in a rope walker configuration. The rope walker configuration would require some gear removal before a fast descent could be realized.
Other than the Unicender rope walker configuration, a properly set up RADS is about as effective as the Unicender and has the advantage of having a 3:1 MA for the arms to permit ascents without messing with footloops once you get in the tree.
And it should be stated that the Unicender can be setup in a RADS configuration, but it's not quite as clean as a Grigri based RADS.
- Location
- Central Hardwood Belt, USA
Re: Petzl Dual Ascender Build
All that is good,
but the dual ascenders capitalize on and maximize the innate benefits of 1:1 climbing.
In keeping with staying on-topic with the title of the thread, I would like to
dig in to a couple dozen pictures that show just how to make a set of these, and a get a deeper, behind-the-scenes look into the nitty gritties of the thoughts behind the reasons. The details.
Step 1, get a left and a right Petzl Ascension.
The right is going to become the left,
and the left is going to become the right.
All that is good,
but the dual ascenders capitalize on and maximize the innate benefits of 1:1 climbing.
In keeping with staying on-topic with the title of the thread, I would like to
dig in to a couple dozen pictures that show just how to make a set of these, and a get a deeper, behind-the-scenes look into the nitty gritties of the thoughts behind the reasons. The details.
Step 1, get a left and a right Petzl Ascension.
The right is going to become the left,
and the left is going to become the right.
Attachments
- Location
- Central Hardwood Belt, USA
- Location
- Central Hardwood Belt, USA
Re: Petzl Dual Ascender Build
I'd like to post 4 pictures per post, otherwise this could take a long time.
Getting ready, getting your stuff in order, bonding sealant-adhesive (Ethicone)
and clamping devices, chopsticks and tongue depressors.
Really high tech. The Ethicone is the bomb, at three hundred pounds per square inch bonding power, I calculated ~9-1/2 square inches, that's over a <u>ton</u> of bonding force.
I'd like to post 4 pictures per post, otherwise this could take a long time.
Getting ready, getting your stuff in order, bonding sealant-adhesive (Ethicone)
and clamping devices, chopsticks and tongue depressors.
Really high tech. The Ethicone is the bomb, at three hundred pounds per square inch bonding power, I calculated ~9-1/2 square inches, that's over a <u>ton</u> of bonding force.
Attachments
- Location
- Central Hardwood Belt, USA
- Location
- Central Hardwood Belt, USA
- Location
- Central Hardwood Belt, USA
- Location
- Central Hardwood Belt, USA
- Location
- Central Hardwood Belt, USA
- Location
- Central Hardwood Belt, USA
