teressa green
ArboristSite Operative
You Want To Find Out If You Can Decend On A Fig 8 Try It ,
Descending using your figure 8
- Thread starter Redbug
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Burnham
ArboristSite Operative
For those of you who are either using in fact or advocating in theory the use of a friction hitch as a backup to a rappel device, I offer the following link:
http://storrick.cnchost.com/VerticalDevicesPage/Misc/RappelSafetyPost.html
Dr. Gary Storrick is well respected in the cavers' world, where developement of vertical rope techniques and skills really push the envelope. If you have not visited his site to review information on ascender/descender equipment and related subjects, you have missed an invaluable resource.
His document, linked above, is pretty convincing to me and is largely why I reject friction hitch backups to rappel devices. But it is important to note that his comments are directed to SRT descent, not the DdRT systems arborists commonly use. My long rappels are usually on fixed single or double rope, and it is there that the friction hitch backup fails. DdRT systems incorporate much higher background levels of friction and that makes a significant difference in outcomes, but I would caution that DdRT setups with friction savers, in their many variations, might reduce that "rope on tree" friction to low enough levels that the rappeler may be exposed to similar hazards as with SRT.
http://storrick.cnchost.com/VerticalDevicesPage/Misc/RappelSafetyPost.html
Dr. Gary Storrick is well respected in the cavers' world, where developement of vertical rope techniques and skills really push the envelope. If you have not visited his site to review information on ascender/descender equipment and related subjects, you have missed an invaluable resource.
His document, linked above, is pretty convincing to me and is largely why I reject friction hitch backups to rappel devices. But it is important to note that his comments are directed to SRT descent, not the DdRT systems arborists commonly use. My long rappels are usually on fixed single or double rope, and it is there that the friction hitch backup fails. DdRT systems incorporate much higher background levels of friction and that makes a significant difference in outcomes, but I would caution that DdRT setups with friction savers, in their many variations, might reduce that "rope on tree" friction to low enough levels that the rappeler may be exposed to similar hazards as with SRT.
Lumberjack
Banned
I never back up the 8, when repeling SRT i use the pezel I'd or an 8. If i am gonna be stopping on the way down to work i use the I'd, if not its the 8.
Using the 8 I never back it up. If i change my mind and need to stop while coming down its a softlock with the tail tied, but not a full hard lock. I dont trust the soft lock for any real length of time.
Using the 8 I never back it up. If i change my mind and need to stop while coming down its a softlock with the tail tied, but not a full hard lock. I dont trust the soft lock for any real length of time.
Tree Machine
Addicted to ArboristSite
I never back up my friction device, per se. I do, however, keep two delta links up front. The second one I'll clip a biner to it, and clip that to the rope. This is not backed up by any means, but is my device were to detonate or something, the rope will still be in front of my hips.
Redbug
ArboristSite Member
Storrick's caving article (posted above by Burnham), about hitches as backup is VERY sobering. The Petzl I'D is probably safer since you have to pull the handle to descend, it stops when you have to let it go for some reason. I've never tried one of those. The method Lumberjack is using makes a lot of sense. I have used the figure 8, but was thinking safety, since they drill it into you when tower climbing about always having a backup system.
Tree Machine
Addicted to ArboristSite
Have you guys seen the Petzl ASAP ? It's a back up device that's designed to arrest a free fall or an overly speedy rappel. It is activated by speed, or acceleration. The principal is much like a clutch; it is an inertia reel.
It is strictly a SRT thing, but will accomodate 13 mm rope.
It's a nifty piece, great concept, but I am unsure of it's utility in our world. Probably tower work and other aerial disciplines where fall arrest is critical.
It is strictly a SRT thing, but will accomodate 13 mm rope.
It's a nifty piece, great concept, but I am unsure of it's utility in our world. Probably tower work and other aerial disciplines where fall arrest is critical.
Koa Man
Kahuna giganticus
Nah, a coconut would fall on your head going up, never on the way down. All coconuts, flowers and seed pods are removed when trimming.stephenbullman said:
Lumberjack
Banned
Redbug said:
I dont see a need to back up either an I'd or an 8 for the way that i use them.
If either ever fail, i am SOL anyway you look at it, my 8 is rated to 10k, forget what the id is rated. I tried working off an 8 but i had a hard time with the hitch.
As much as i used to be for SRT, i couldnt tell you the last time i used it. It is still king for going up fast and effeciently, but not what i perfer. I rarely have to climb more than 40-50 to start working.
My mom asked me last weekend what i would be tied to if the tree failed. I told her that they better open the doors to he-ll because i am gonna be comin in fast. She failed to see the humor, go figure.
Burnham
ArboristSite Operative
Lumberjack said:
Lumberjack, and Tree Machine, too, I don't think you have to worry about your 8 spontaneously failing or detonating
; heck, Carl, most rec 8's come in at around 30 Kn, and rescue models go higher than that...the problem will not be equipment failure, it will be operator error. Unless you are working alone, I see no reason not to have your groundie take hold of your rope while you rappel on your 8, it's such an easy belay. I suspect some macho issue may hinder us in making this choice (I am not immune
). Obviously the I'D backs itself up in case of operator error...it isn't going to blow apart either...Burnham
ArboristSite Operative
Tree Machine said:
TM, this is a new one for me, thanks alot, I'm going to look into it some more. In long SRT raps from old growth it might have some application, and I do some tower work, too...belaying the ladder climbs is often a hassle.
Lumberjack
Banned
Burnham said:
My 8 is rated to 10k pounds, more than my rope or biners are.
Burnham
ArboristSite Operative
Oops, my bad, Carl. I read your post incorrectly...I saw 10Kn and you did indeed write 10k. We are on the same page now...thanks. That sucker is bombproof strong.
Do you see what I mean about operator error rather than equipment failure being the risk when one uses the 8?
Do you see what I mean about operator error rather than equipment failure being the risk when one uses the 8?
