Worth mention ...

Kevin

Kevin

Location
Ontario, Canada
In the Tree Climbers Companion I read where they suggest using a prusik hitch above a double ascender like the Kong and allow the ascender to advance the hitch.
The problem is the hitch is in the open position because of the spread in the rope caused by the ascender.
If a climber footlocked up and removed the ascender without setting the hitch it could make for a quick trip to the ground.
 
I have never used an ascender or even seen one in use, but I'm probably going to get one (or two) within the next couple months. After reading several opinions and versions, as well as envisioning it in my mind, I believe I would use my friction hitch (distel)above the ascender and push it up with the ascender. This would not only make a good backup, but it would allow me to sit in my saddle and rest (or cut an offending limb out of my way) on my way up.
 
Kevin,

Would you tell me the page in the Companion you found the recommendation?

The prusik would not be the best friction hitch to use. Better to use one of the spiraling hitches like a Klemheist or Kreutzklem. The prusik has a bad reputation of not locking of unless it's kept snugly dressed.

Also, using cord that has a pretty soft hand. Stiff cord is less likely to bite down when you need it most.

Tom
 
Tom,
My book is at work in my truck.
There`s a picture of a climber footlocking with a mechanical ascender.
Any other hitch would likely be ok but not the prusik.
If your footlock slipped while removing the ascender before you could set the prusik you`d be eating dirt pretty quick.
If you can`t find it I`ll get the page tomorrow.
 
Tom,
Don`t hate me but I forgot to bring the book home.
blush.gif

Did you find it by chance?
If not I`ll reply to this from work in the morning.
Sorry about that.
 
Found it on page 47.

while you're looking, go to the bottom picture on page 65. Recognize that guy? Maybe if I turn "this" way...no...how about if I put on a different helmet? Jeff had Brian Kotwicka draw me into the book. If you go to page 41 you'll find a pic of Jeff's Dad.

Tom
 
To back up a doubled ascender, try running up an alpine butterfly to choke the limb. You should still have two ropes to ascend. Place the doubled ascenders on the line. Tie a friction hitch above the ascender on the leg of line that is choked solid.

If the running leg ascender fails, the choked leg ascender will hold the fall. If the choked leg ascender fails, the hitch will hold the climber.

The advantage with the doubled rope is less stretch over SRT. I thought about this a good while ago, but never got round to trying it - let me know what you think!
 
Hi "MrPez",
Backing up a double ascender is indeed one of my main problems now. Up to now, I've been using a Kong twin ascender without back-up, but I must solve this problem at least for my tree climbing courses. I would be happy to use a back-up myself, but I'm not willing to take up much friction. The hitches I've tried so far either increase friction too much or, when let loose, makes me doubt if it would really work in case one of the ascenders failed (I'm also not willing to open my ascender and dive down in order to test it).
Your idea of choking one line is very interesting... It makes me think... wouldn't it be a good idea at this point simply to choke both ends of the rope with a Girth Hitch on top? I realize this increases the work of rope installation and resetting afterwards, but I guess this way one could simply footlock up with no need of any back-up (each ascender would back up the other).
What do you think?
Any (good) ideas are welcome...

Sergio
 
Sergio,
Have you looked at the Petzl Mini-Traxion? I've had the opportunity to try one and it's super-smooth. Advances with virtually no resistance, but will not descend without unlocking it. It's rated for 900 lbs in life support situations, and 4500 total load on the pulley.

I have a question on strength ratings and ANSI standards, but I will start another thread for that.
 
Ghivelder,
What hitches have you tried and what size of rope are you using for your hitch?
I`ve backed up my Kong on a static line with a distel using 1/2" rope and it worked well.
I tie it below the ascender.
 
Brian,
I know the Mini-Traxion. But how do you mean to use it?
Kevin,
I'm using a soft 10mm polyester rope. The problem is that the ascenders keep the rope slightly apart. The friction hitch, in order to work properly, must squeeze them a bit which adds a not indeferent amount of friction. If you let the hitch very loose, it's true there is little friction, but you can't be sure how long the hitch will take before biting the rope. A back-up that catches me after 3 feet is useless since I might hit something and hurt myself before that. The scenario gets even more complicated if you think that, in real life, only one of the ascenders will fail (unfortunately, I've seen it happening myself) which means that one of the ropes will be passing inside the hitch going upwards. The situation has so many variables that makes it almost impossible to really test the performance of the back-up.
The point is that if I have to win a whole lot of friction while footlocking, then I might just as well go up with a single rope, where there are multiple choices for the back-up.
I'm still waiting for some (good) ideas...
Tonight, no sleeping! Everybody thinking on how to back-up a double ascender!!!
I expect a full report by tomorrow morning!

Sergio
 
Sergio

I still haven't had a chance to try what I suggested. However, the only problem I foresee is the two ropes trapping the hitch. Have you tried tying an 8mm double braid with a Klemheist above the ascender and then clipping it into the bottom of the ascender. I always tie 8 fingers.

Don't worry too much about it not gripping - it always has for me when the ascender slipped. As soon as I try it I'll let you know.

Is February still an option?
wink.gif
 
The other day I tried a distal hitch attached on the front D's of my saddle. The hitch was tied with a short 3/8" Tenex eye to eye tail. I clipped a carabiner under the hitch to act as a fairlead. It didn't create a lot of friction and stopped me on short falls with only one ascender attached to the doubled line. With the hitch real short it does not appear that the failed ascender will hit the hitch and cause a fall. I also have a concern about one of the ropes moving upward and causing the hitch to not funtion properly. This system appears to have some potential but I have not climbed with it enough to see how it will work.
 
<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>Originally posted by MrPez:
To back up a doubled ascender, try running up an alpine butterfly to choke the limb.
If the running leg ascender fails, the choked leg ascender will hold the fall. If the choked leg ascender fails, the hitch will hold the climber.
!<HR></BLOCKQUOTE>

As another backup, you can tie off the end of the choked leg to the trunk or another anchor. Ground crew can untie it when you are up top.
 
If ascending DdRT into a drity crown I will use a klemhiest backup under the doubled ascenders. I never load it fully so it slides easily up the rope with my second hand.

Brian, what you speak of is not usable with doubled ascenders, only SRT and traditionaly system asn you did swapping the MT for a friction hitch as self belay to ascend.
 
I think I’ve got an interesting solution to the problem.
I’m thinking of big trees in which one prefers to use a separate access line.
Hoping Mr. Dunlap will appreciate it, I’ll call it the “True Double Rope” technique – or TDR.
In fact, it’s very simple: If your access line is 200 feet long, get another one just 100 feet long and attach it with a blake’s to the middle of the first one. Install the rope as you would in normal SRT and – by magic – you have two ropes hanging instead of one!!!
Since both lines are fixed, any double ascender can be used without a back-up. One could even use a pantin while footlocking (SRT climbers that like using the pantin could use the same system to solve the problem of the lack of a back-up). In fact, I think that the TDR, with it’s two choked lines, offers the possibility of using many different accent techniques and devices.
Once on top, the climber can decide whether to leave the “half rope” or untie the blake’s and drop it down.
I love using Kong’s double ascenders (I’ve also got a version of it made for Komet with a single handle instead of two – very nice if you must keep it on your harness), but if you push it up against a branch while footlocking there is a serious risk that it might open. I’ve seen it happening twice! Since then I had Kong modify a few ascenders for my courses in which there is a hole that, clipping a small binner in, prevents the cams from opening. That makes me feel much better but, conceptually, it’s still not a back-up since it wouldn’t work in case of total failure.
“True Double Rope” could be an easy way to back-up a double ascender without adding any friction to the system.
Let me know what you guys think…

Sergio
 
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