Unicender?

[YuccaPatrol]

I just came across this device while looking at some tree climbing sites. It seems pretty bizarre and is claimed to be used for BOTH ascending and descending.

Has anybody actually used or held one of these?


http://www.thompsontreetools.com/product.html

[Evan G]

Talk about too many moving parts, Wow! Interesting..........

[chh]

I do know it can be used for both ascending and descending. You can find video of tree workers using it if you look. I've never used or held one, but based on the picture I'd say it works a little like the love child between a gri-gri and a rack. The rope makes some back and forth passes like a rack and when it's weighted the "spine" of the thing creates bends. When you pull on the lever, the spine elongates or straightens and the bends are eliminated. I know some tree workers swear by it, but like I said, I've never used one.

[Carl Amundson]

Here is a video of the device:
http://www.youtube.com/watch?v=9FLiFUlXWNE&feature=related

It looks like a lot of work to ascend.
I guess the next question is; How well does it work on wet/muddy rope?

[Stridergdm]

Here is a video of the device:
http://www.youtube.com/watch?v=9FLiFUlXWNE&feature=related

It looks like a lot of work to ascend.
I guess the next question is; How well does it work on wet/muddy rope?

Well two URLs:

Manufacturer site at $450 a bit (ok a lot) more than I'd be willing to spend on "checking it out".

Storrick's review. As he points out, it's not designed as a caving device, but apparently someone has tried it..

[chh]

hey junkman, I get the feeling this device would work very well on muddy ropes. Might perform similarly to other camming descenders on wet ropes though, I don't know.
The cost is prohibitive, otherwise I would love to have and/or try one. I wouldn't use it for caving though, only for tree climbing. Wet ropes are encountered in tree work on occasion, and muddy ropes virtually never. Also, our styles of ascent differ greatly from caving as getting up and down a rope is really only a very small percentage of the overall work involved. We aren't really as concerned with efficiency climbing a rope as cavers are. But that being said, I've seen tree workers footlock up a rope using less energy than some cavers I've seen using their various systems. I guess "muscle memory" plays a big part. On the other hand, we are rarely going more than a hundred feet in a straight vertical line so we can afford to spend a little more energy there. Our climbing systems (in my opinion) are based more around work positioning, not point A to point B if that makes sense.
But as far as tree climbing goes I'm still in the dark ages. Using knots!

Happy Holidays!

-chh

[caverdan]

If you read the discription, it mentions being used recreationally using DRT. double rope technique. My bet is you need really thick and supple rope or doubled up climbing rope for this thing to work properly. It would be great to try canyoneering where double rope repels are the norm. Static rope could get scary fast. Tree climbing rope is very different from the static rope we are use to using. Some can take a hit from a chain saw and keep on ticking.

[chh]

you're right caverdan. tree ropes and cave ropes are very different. But I can say from personal experience that none of the tree ropes I've used can take a chainsaw and survive I have hit rigging ropes, but they "survived" more because of the glancing cut as opposed to their inherent toughness, though they are fairly tough.
Don't cut yer rope with a chainsaw.....mmmmk?

[caverdan]

Don't cut yer rope with a chainsaw.....mmmmk?

That's bad....No??

I can't find a link now, but they use to make a rope with small steel cables wove into the rope. I saw it at a trade show in Denver several years ago.

[chh]

caver dan, we have a steel cable lanyard for big (or particularly sappy) removals. It WILL take a chainsaw strike, but I don't like climbing with them. I've never seen a climbing line with a steel core though. I would think OSHA might require that a climbing line have a certain amount of dynamic quality, but I could be wrong. I can't imagine working with a steel core either, but then again old pit rope might as well be steel
Was it a rope you saw, or a positioning lanyard? What kind of trade show?

[cavedoc]

If you read the discription, it mentions being used recreationally using DRT. double rope technique. My bet is you need really thick and supple rope or doubled up climbing rope for this thing to work properly. It would be great to try canyoneering where double rope repels are the norm.

I think the double rope technique here is a tree technique using a pulley for mechanical advantage, not using two strands at once as in a double rope rappel. I believe the rope runs through a pulley at the top of the tree, one end is attached to you, and the the "free" end comes back down and into the device. chh, is that right? So it may not accept two strands of rope at once.

[Scott McCrea]

I believe the rope just runs thru the crotch of tree branch or ring on a rigging strap. No pulleys.

[chh]

Actually, we do use pulleys at times or rings in order to do two things: reduce the friction on the system but also to protect the cambium layer of the tree. Most folks just use the two rings scott mentioned. The pulley versions of these anchors being a lot like the unicender.....to much money for the average joe (including me). These anchors are also typically retrievable from the ground and installable from the ground as well, though most of the time I climb to my tie in point. Running a climbing line over the branch will damage a lot of trees, thus we call them "cambium savers" for this, their primary function.
While a pulley does provide a mechanical advantage when body thrusting as soon as you redirect over another branch in the crown, you've done away with it. Pulleys are used in tree climbing, but I would say rings are far more commonas a primary tie in point. Pulleys can also be handy in a redirect below your main tie in point. The caveat being you have to climb back to it to retrieve it.
It looks to me like the unicender was designed for a single, thicker, arborist style rope. I can't say if it would accept two strands of a thinner diameter, like 7 or 8's used in pull downs. Like I said, too rich for my blood. The cost outweighs what benefit I could glean from it at least until they start paying me more.....

[chh]

cavedoc, yes you understand it correctly. The typical setup is more like a toprope self belay than a rappel on a doubled rope, though the term "double rope technique" is a little misleading.

[bronzzhorse]

im just thinking to myself here.... how many complete frog rigs can i make for 450 bucks.??I watched the video on the Manufacturers site, and it looks to me like more work than a frog set-up..... and cost WAYYYYYYYY more... how many frog rigs can i wear out in the same time as one of the unicenders..... im guessing less than 450 dollars worth.
Heck for that matter, i could BUILD an 12v powered ascender for 450$, and climb by hitting the button....... I do however like the fact that you can go up OR down with the unicender....that little detail is nice, but still, not worth 450 dollars