rock exotica

newguy18 · 15th December 2007, 04:37 PM

So can you order it from them?I know Ekka orders from wesspur so I don't see the issue with out of country orders.

Tree Machine · 15th December 2007, 07:10 PM

.

newguy18 · 15th December 2007, 07:22 PM

Looks like an accident waiting to happen but then again in this industry so is running a saw recklessly or not double checking your lines.

Tree Machine · 15th December 2007, 07:36 PM

Personally, I applaud this;

Tree Machine · 15th December 2007, 07:54 PM

Quercus, you've outdone yourself. As far as the Kong information you offer, destructive testing with objective measurements and observation to see if rivets go, or holes go first. And one or the other will. From my personal years with the Kongs, as eartlier said, are fine. But in 20 years. We just wouldn't know til thin.

As far as the points you put forth about the Petzl duals, there is nothing I can disagree with.

Good Job.

quercus · 15th December 2007, 11:55 PM

Quote:

Originally Posted by newguy18

So can you order it from them?I know Ekka orders from wesspur so I don't see the issue with out of country orders.

the device is not CE certified so they cannot send it to my country. It would be illegal to sell it here. In a few months a friend of mine is going to the US. He'll buy it there and bring it to belgium is he has the chance...

vandal · 16th December 2007, 08:16 PM

quercus,

regarding your prussic backup of double ascender, will it work if only one ascender fails? try it on the ground locking one side and leaving other side open and see if prussic grabs.

quercus · 16th December 2007, 09:22 PM

Yes that does work. At first it didn't but when you leave about 50 cm of slack between the prussik and the stopper knot it's not a problem. I've been testing this for a long time now.

Ekka · 17th December 2007, 01:31 AM

Quote:

Originally Posted by vandal

quercus,

regarding your prussic backup of double ascender, will it work if only one ascender fails? try it on the ground locking one side and leaving other side open and see if prussic grabs.

Welcome Vandal

Yes it does, they back the MarBars up same for that reason.

George Hayduke · 17th December 2007, 08:47 AM

Applaud?!?!

Using rope on rope in a backup setup? You MUST be joking!

NOT a good setup-clever though-

What happens when you climb into a bee's nest and need to escape from your ascent setup quickly? How do you do a changeover?

Tree climbers go through such contortions to make backups that are more dangerous than not having a backup.

Far simpler and safer to use:

SRT
Chest ascender
Foot ascender
Upper ascender with long foot loop stirrup

Frog walker works better or RADS.

Tree Machine · 17th December 2007, 11:00 AM

Oh George, in my own simple opinion, you are complicating things several levels. Chest ascender? That limits motion, keeps you vertical, backs up your other ascender, absolutely wonderful if your wish is to maintain a vertical position.

But we're tree climbers, not vertical cavers. Our needs are unique and different.

First, George, SRT needs to be in every climber's repertoir, that's my feeling, and apparently yours. But the way Quercus is approaching ascent, 1:1 ascent using twin acenders, he now has the option of SRT, his 1:1 doubled ascent and also 2:1 doubled ascent, ALL THREE SYSTEMS. He's had the courage to come forth with his Petzl Twins and show us the benefits he enjoys over 2:1 friction hitch ascent or SRT ascent.

(Don't take too much credit, Quercus. This has been done before with Petzls Ascension L-R's, Tree b uh zz)

But addressing Quercus' rope backup through the cams, creating rope-on-rope friction 50 cm away, that's hardly different than a traditional friction hitch system, except the rope is compressing both legs, rather than 1 leg like in friction hitch climbing.

This is special, and I would like to share why.

One thing to note on ascending a 1:1 dual line; if one of the two cams opens up, completely allowing the rope to move freely, you are now in a 2:1 mechanical advantage system where one leg is moving up, and the other down. If the ropes are moving in opposition to each other, if the two sides of the rope are made to be securely proximal to one another (unable to seperate) your rope behavior and friction control become much more predictable. You've eliminated certain variables.

With this promise that the rope pair can not possibly escape the ascender shell, a cam failure on one side becomes a 2:1 system in motion. A climber's grip around the two ropes, compressing the two opposing frictional surfaces, the 'up' rope is creating drag on the 'down' rope and the 'down' rope is creating drag on the 'up' rope. This site of friction where the two ropes touch and pass has a doubling effect in the sense of friction, and your grip can magnify that duo-rope, rope-on-rope friction and add to it 'glove-on-rope', your hand receiving and giving that same opposing direction friction.

This is almost exactly what a friction hitch accomplishes, except it acts on only one of the two legs of the system, and friction only going a single direction.

In our scenario, when a cam is accidentally released, you instinctively grab the duo rope and create a remarkable amount of frictional force with your compressional grip.

Now that we understand better our control of the friction with a gloved hand, add to that the additional friction of the motion of the rope over the crotch at your tie-in.

There's a lot of friction that can be mustered coming off a 1:1 and into a 2:1. And that's why the friction hitch works so remarkably well in a 2:1 system; because it doesn't have to apply a lot of compressional force to create enough friction on just one leg of the 2:1. In our example above we are creating bidirectional pressure on both legs. I believe you may only have to use half as much grip pressure on the dual ropes as would a friction hitch on the single leg. That, math, I'm not 100 % certain on, it's more of a rough guess, based on probably 10,000 ascents on the system we're discussing.

Tree Machine · 17th December 2007, 11:14 AM

My PTO pin or Quercus' prussic rope, they add no appreciable friction to the ascent. His, though, offers secure backup, Tree Machine's PTO pin does not. BOTH promise to keep the rope from escaping the ascender shell. Both are quick-on, quick off.

A cam letting loose is a very, very rare event, but your odds really can go down depending on how aggresive or careless you are with your climbing.

In 1:1 ascent, IF a cam DOES let loose, and you grab the twin ropes above or below the ascender (it doesn't matter) you can apply enough friction to stop yourself. The absolute must here is that the ropes can not ever, ever escape the ascender shell and become seperate of one another.

With that promise, the likelihood of an injury accident on dual ascenders diminishes greatly in the case of one of these rare events.

With Quercus's Petzl Twins, as per his claim, the likelihood of catastrophic failure of the asender set is further diminished. If the Petzl Ascension is inherently a safer ascender than the Kong, then the likelihood of a cam opening accidentally is also further diminished. We now have a safer 1:1 ascent system. Good on you, Quercus!

Add to this, my personal preference is a single-handle dual ascender over a dual-handle dual ascender (I have one hand on the handle, one hand on the rope pair just below).

I will be upgrading to Quercus' Petzl system for 2008. Thank you, Quercus.

Tree Machine · 17th December 2007, 11:21 AM

I wonder what Petzl would have to say about all of this.

Tree Machine · 17th December 2007, 11:21 AM

I wonder what Kong would have to say about all of this.

Tree Machine · 17th December 2007, 11:49 AM

Hey Quercus, I have a question.

When this thread opened, I thought you might be wanting the Rock Exotica Dualcenders for your primary ascender.
Then you show us your primary ascender, so I thought you might be wanting the Rock Exotica for your backup.
Then you show us your backup.

What DO you want the Rock Exotica Dualcender for?

George Hayduke · 17th December 2007, 10:21 PM

TM,

Before you rant so much clarify if you're talking about ascent or working. Two different issues. Jumping between the two topics does no good. You rattle on about how different arb work is from rope access. no different in the access or ascent phase, at least to me.

Rope on rope in a friction hitch is completely different than using the rope in this capacity. Why do it when a hitch pin like you use is better? Doesn't make sense and I'll bet that if this setup were shopped around to other arb sites, cavers, rope rescue, etc. forums that there would be similar reactions as mine. It's tempting to run with it but it isn't my setup.

Ekka · 17th December 2007, 10:29 PM

So how would you back up the mar bars?

I think personally if you are going up SRT or double rope but installed as SRT use such as dual ascenders or mar bars and you get hammered by bees then you are in deep shit!

Which ever way I look at it you are going to have to do a switch over.

By the way, I cant speak from experience here as I dont do SRT ascents only descents but for everyone else I'm sure they're reading.

15th December 2007, 04:37 PM	#26 (permalink)
newguy18 Part of the Furniture Join Date: Jun 2007 Location: Dead twig Florida. Posts: 4,062	Re: rock exotica So can you order it from them?I know Ekka orders from wesspur so I don't see the issue with out of country orders. __________________ Have your say join us today. I ship USA saws out of the USA "Everybody's hell on safety." G.f.beranek. www.atreestory.com Last edited by newguy18 : 15th December 2007 at 07:20 PM. Reason: typos argh.

15th December 2007, 07:22 PM	#28 (permalink)
newguy18 Part of the Furniture Join Date: Jun 2007 Location: Dead twig Florida. Posts: 4,062	Re: rock exotica Looks like an accident waiting to happen but then again in this industry so is running a saw recklessly or not double checking your lines. __________________ Have your say join us today. I ship USA saws out of the USA "Everybody's hell on safety." G.f.beranek. www.atreestory.com

16th December 2007, 08:16 PM	#32 (permalink)
vandal I'm new here so be nice Join Date: Oct 2007 Location: Philly Posts: 1	Re: rock exotica quercus, regarding your prussic backup of double ascender, will it work if only one ascender fails? try it on the ground locking one side and leaving other side open and see if prussic grabs.

16th December 2007, 09:22 PM	#33 (permalink)
quercus Mature tree Join Date: Nov 2007 Location: belgium Posts: 421	Re: rock exotica Yes that does work. At first it didn't but when you leave about 50 cm of slack between the prussik and the stopper knot it's not a problem. I've been testing this for a long time now.

17th December 2007, 08:47 AM	#35 (permalink)
George Hayduke Banned Join Date: May 2007 Location: Slickrock, USA Posts: 92	Re: rock exotica Applaud?!?! Using rope on rope in a backup setup? You MUST be joking! NOT a good setup-clever though- What happens when you climb into a bee's nest and need to escape from your ascent setup quickly? How do you do a changeover? Tree climbers go through such contortions to make backups that are more dangerous than not having a backup. Far simpler and safer to use: SRT Chest ascender Foot ascender Upper ascender with long foot loop stirrup Frog walker works better or RADS.

17th December 2007, 11:00 AM	#36 (permalink)
Tree Machine Over mature heritage tree Join Date: Mar 2007 Location: Indianapolis Posts: 714	Oh George, in my own simple opinion, you are complicating things several levels. Chest ascender? That limits motion, keeps you vertical, backs up your other ascender, absolutely wonderful if your wish is to maintain a vertical position. But we're tree climbers, not vertical cavers. Our needs are unique and different. First, George, SRT needs to be in every climber's repertoir, that's my feeling, and apparently yours. But the way Quercus is approaching ascent, 1:1 ascent using twin acenders, he now has the option of SRT, his 1:1 doubled ascent and also 2:1 doubled ascent, ALL THREE SYSTEMS. He's had the courage to come forth with his Petzl Twins and show us the benefits he enjoys over 2:1 friction hitch ascent or SRT ascent. (Don't take too much credit, Quercus. This has been done before with Petzls Ascension L-R's, Tree b uh zz) But addressing Quercus' rope backup through the cams, creating rope-on-rope friction 50 cm away, that's hardly different than a traditional friction hitch system, except the rope is compressing both legs, rather than 1 leg like in friction hitch climbing. This is special, and I would like to share why. One thing to note on ascending a 1:1 dual line; if one of the two cams opens up, completely allowing the rope to move freely, you are now in a 2:1 mechanical advantage system where one leg is moving up, and the other down. If the ropes are moving in opposition to each other, if the two sides of the rope are made to be securely proximal to one another (unable to seperate) your rope behavior and friction control become much more predictable. You've eliminated certain variables. With this promise that the rope pair can not possibly escape the ascender shell, a cam failure on one side becomes a 2:1 system in motion. A climber's grip around the two ropes, compressing the two opposing frictional surfaces, the 'up' rope is creating drag on the 'down' rope and the 'down' rope is creating drag on the 'up' rope. This site of friction where the two ropes touch and pass has a doubling effect in the sense of friction, and your grip can magnify that duo-rope, rope-on-rope friction and add to it 'glove-on-rope', your hand receiving and giving that same opposing direction friction. This is almost exactly what a friction hitch accomplishes, except it acts on only one of the two legs of the system, and friction only going a single direction. In our scenario, when a cam is accidentally released, you instinctively grab the duo rope and create a remarkable amount of frictional force with your compressional grip. Now that we understand better our control of the friction with a gloved hand, add to that the additional friction of the motion of the rope over the crotch at your tie-in. There's a lot of friction that can be mustered coming off a 1:1 and into a 2:1. And that's why the friction hitch works so remarkably well in a 2:1 system; because it doesn't have to apply a lot of compressional force to create enough friction on just one leg of the 2:1. In our example above we are creating bidirectional pressure on both legs. I believe you may only have to use half as much grip pressure on the dual ropes as would a friction hitch on the single leg. That, math, I'm not 100 % certain on, it's more of a rough guess, based on probably 10,000 ascents on the system we're discussing.

17th December 2007, 11:14 AM	#37 (permalink)
Tree Machine Over mature heritage tree Join Date: Mar 2007 Location: Indianapolis Posts: 714	part 2 My PTO pin or Quercus' prussic rope, they add no appreciable friction to the ascent. His, though, offers secure backup, Tree Machine's PTO pin does not. BOTH promise to keep the rope from escaping the ascender shell. Both are quick-on, quick off. A cam letting loose is a very, very rare event, but your odds really can go down depending on how aggresive or careless you are with your climbing. In 1:1 ascent, IF a cam DOES let loose, and you grab the twin ropes above or below the ascender (it doesn't matter) you can apply enough friction to stop yourself. The absolute must here is that the ropes can not ever, ever escape the ascender shell and become seperate of one another. With that promise, the likelihood of an injury accident on dual ascenders diminishes greatly in the case of one of these rare events. With Quercus's Petzl Twins, as per his claim, the likelihood of catastrophic failure of the asender set is further diminished. If the Petzl Ascension is inherently a safer ascender than the Kong, then the likelihood of a cam opening accidentally is also further diminished. We now have a safer 1:1 ascent system. Good on you, Quercus! Add to this, my personal preference is a single-handle dual ascender over a dual-handle dual ascender (I have one hand on the handle, one hand on the rope pair just below). I will be upgrading to Quercus' Petzl system for 2008. Thank you, Quercus.

17th December 2007, 11:21 AM	#38 (permalink)
Tree Machine Over mature heritage tree Join Date: Mar 2007 Location: Indianapolis Posts: 714	Petzl I wonder what Petzl would have to say about all of this.

17th December 2007, 11:21 AM	#39 (permalink)
Tree Machine Over mature heritage tree Join Date: Mar 2007 Location: Indianapolis Posts: 714	Kong I wonder what Kong would have to say about all of this.

17th December 2007, 11:49 AM	#40 (permalink)
Tree Machine Over mature heritage tree Join Date: Mar 2007 Location: Indianapolis Posts: 714	???? Hey Quercus, I have a question. When this thread opened, I thought you might be wanting the Rock Exotica Dualcenders for your primary ascender. Then you show us your primary ascender, so I thought you might be wanting the Rock Exotica for your backup. Then you show us your backup. What DO you want the Rock Exotica Dualcender for?

17th December 2007, 10:21 PM	#41 (permalink)
George Hayduke Banned Join Date: May 2007 Location: Slickrock, USA Posts: 92	Re: rock exotica TM, Before you rant so much clarify if you're talking about ascent or working. Two different issues. Jumping between the two topics does no good. You rattle on about how different arb work is from rope access. no different in the access or ascent phase, at least to me. Rope on rope in a friction hitch is completely different than using the rope in this capacity. Why do it when a hitch pin like you use is better? Doesn't make sense and I'll bet that if this setup were shopped around to other arb sites, cavers, rope rescue, etc. forums that there would be similar reactions as mine. It's tempting to run with it but it isn't my setup.

17th December 2007, 10:29 PM	#42 (permalink)
Ekka Admin - Dip Arb & Hort Join Date: Jan 2007 Location: Brisbane Posts: 7,734	Re: rock exotica So how would you back up the mar bars? I think personally if you are going up SRT or double rope but installed as SRT use such as dual ascenders or mar bars and you get hammered by bees then you are in deep shit! Which ever way I look at it you are going to have to do a switch over. By the way, I cant speak from experience here as I dont do SRT ascents only descents but for everyone else I'm sure they're reading. __________________ Arborist Training in Australia\| Your Free Helping Guide Free Tree and Green Industry Link Directory .... Yes, I also SEO (Optimize) and build websites that fly high in Google Qualified Brisbane Tree Lopping \| Stump Grinding and Stump Removal Brisbane Brisbane - Gold Coast Tree Care, Consulting, Developer, Tree and Arborist Reports Forum Sponsors