This subject has been nudged around at the ISA board but there are some folks on this page taht I don't see at the ISA so I will lay it out here too.

Mechanical ascenders have been adapted by tree climbers from other disciplines within the vertical world. The use procedures by arbos has been a little less disciplined though. How many people or companies have a backup policy for ascender use? IF there is a back up policy for mechanical ascenders, what about knot ascenders, ie, Klemheist or Prusik?

Does anyone have any hearsay or actual experience with ascneding sytems failing? If so, what are the exact details? If you know of someone who had a failure, I would like to talk with them. I respect privacy and do not tell stories "out of school" and will keep names and incidents in confidence if asked.

The reason that I am asking this question is that all of the stories that I have been able to track to their source, it was "pilot error" that caused the fall. There have been accidents and near misses with Pruski use that, I think, could have been prevented by using the Klemheist. In caving, it is standard not to be attached to the rope by only one system. Two or three attachments is the standard. If that is the standard in caves, where the rope climbing systems are the norm, why don't we as arbos, adopt the same procedures?

Backing up my ascenders,

Tom

Reply to post by Tom Dunlap, on May 06, 2000 at 21:25:09:

Tom,
As a practising Arborist who has had experience in vertical rescue i have used both knots and mechanical ascenders to ascend and descend. I have tried many knots ascenders and descenders to try and find a failsafe/foolproof piece of kit that is affordable and can withstand the rigours of our work - i'm still looking.
We are in the game to make money and to obviously turn up for work the next day. There has to be a happy medium, go too far on safety and you loose your time,back this up back that up loose your time and you loose money.
Most practising Arborists i know always have 2 points of attachment - descending and ascending. Main line/climbing line and the flipline/pole strop. Should you need a further back-up?
I have had ascenders and descenders slip or travel on a few occasions. The last was a petzl expedition ascender. The rope was wet after a heavy downpour which i sat out in the tree. Some of the sawdust had collected between the rope and the cam. I went to climb higher sliding the ascender up the rope and the cam jammed. Fortunately for myself my flipline stopped me from exiting the tree too soon.
As i've seen previously mentioned the Tibloc which was supposed to equal the knot ascenders is a pain to use if you haven't the right crab or diam. rope.
I've also tried using the petzl stop as an ascender in certain trees where good climbing limbs are present but even with this they can travel while under load or if you press yourself against the handle. I've looked at the ergonomics of my operation many time - even have a worker belay with a Gri-Gri. This is great and can be quite quick but it's a guy out of the picture while your climbing. What's the answer?
The answer is no piece of kit is foolproof and does't suit every situation .Human error can be a major factor as we know. Every time we tackle a job you have to be in tune with you equipment and your enviroment. Choose the right piece of kit for the job, too many Arborists are still in the dark ages and think that all they can go up and down a rope with is a piece of 7/8ml prusik cord - wake-up!

Reply to post by Tom Dunlap, on May 06, 2000 at 21:25:09:

Tom, I'm really glad you raised this issue. I've been constantly looking for ways to climb safer since a friend died in a fall a couple of years ago. He was working his way down a de-limbed stem during a removal relying only on a lanyard, neglecting to use his climbing rope cinched around the stem as a second tie-in. Now I use a short lanyard close in and a third long lanyard that I always try to have looped over a limb above me. My long lanyard is 16'-foot length of 7/16 arborist rope, which significantly reduces the weight of what some friends regard as an innefficient piece of equipment. But I can quickly reset the lanyare as I move up and horizontally and the length allows a good range of movement for working. Though it's not the perfect failsafe system, I feel more secure climbing with it. The one obvious drawback is that I could possibly fall eight feet or so and come to a sudden, uncomfortable stop. To avoid this, I've attached to one end of the lanyard a rock climbing device known as a "screamer" that is designed to absorb the shock of falls too short to stretch a dynamic kernmantle rope. They come in several forms, but all have the same effect, some better than others.

I've never had any snafus with my New Tribe ascender rig outfitted with CMI ascenders. I only use it as an "elevator" to get into the tops of tall trees with an end of my climbing rope attached to my saddle. I switch to a Blake's hitch system once up. I haven't heard of any ascender scares here in Atlanta, but I'll let you know if I do. Thanks again for starting a discussion on this. I'm eager to read about any other ways folks have found to climb safer.

Tom
Keep looking up!

Reply to post by Dave C, on May 06, 2000 at 21:25:09:

Hi Tom, How on earth (or off it as the case may be) did you accend with a stop??? Climbers tenacity I guess! I am a industrial rope access worker in my spare time on off-shore drilling instalations, as well as a practising arborist for the best part of my life. the contrast in safety standards between the the two industries is galactic. Here we are using the best rope cutting tool, sometimes mm away from our one & only lifeline, (lets not mention the freeclimbers). My only suggestion at this late hour, when using a prussick or simmilar system would be to attach a shunt on a long strop high above the knot tied into your harness, & on your prussick side apply the same until your ready to move. Shunts are light, small, & with a short cord attached to the cam, you can descend with no bother or need to remove. Fact:10yrs ind.rope access-2 fatalities.
10yrs arb-?? (UK figures) Log on!!!

Reply to post by Cameron Hall-Gardiner, on May 09, 2000 at 09:25:25:

While you guys are talking about backing up backups and weather or not to bother, Ive been cleaning and checking my gear. Hand assenders, gri gri, prusik loops, krabs etc etc. The message is, yes there are systems for situations and all these systems are only compatible with specific equipment and by maintaining your equipment and knowing correct compatabilities and knowing the best system for the job at hand is back up in it self.
Oh yeh! avoid user error, dont be complacent.