|
shellwaster
Apr 26, 2009, 7:18 PM
Post #1 of 14
(5598 views)
Shortcut
Registered: Apr 26, 2009
Posts: 1
|
I am climbing a lot of trees lately (repeatably) and a linemens belt is getting annoying/dangereous with the branches. I thought about Prussic knot/ ascender. Once I initally get up to the top height attach a rope with a prussic on it and then strap on at the base everytime I go up and down
|
|
|
|
|
Terry2124
Apr 26, 2009, 7:29 PM
Post #2 of 14
(5588 views)
Shortcut
Registered: Feb 22, 2009
Posts: 223
|
shellwaster wrote: I am climbing a lot of trees lately (repeatably) and a linemens belt is getting annoying/dangereous with the branches. I thought about Prussic knot/ ascender. Once I initally get up to the top height attach a rope with a prussic on it and then strap on at the base everytime I go up and down
A pruisik will work, you can use a grgri as well or both as redundancy. With grigri you can rap down.
|
|
|
|
|
Tree_wrangler
Apr 26, 2009, 8:48 PM
Post #3 of 14
(5575 views)
Shortcut
Registered: Feb 8, 2007
Posts: 403
|
If you're talking about using the prussik as an ascender, that will work fine. Consider tieing in short on the line every so often.
If you're talking about leading on the prussik, while free-climbing through the branches, that too, is acceptable in trees, although you need to have 2 in the system, as one wouldn't be that safe.
When in trees, and "leading", be a little wary of self-belay devices meant for rock, and of using really stretchy dynamic ropes meant for rock. These systems are meant to handle great force, and they handle that force by slowing falls over longer distances. Due to the high forces found on rocks, prussiks are usually not recommended, as they can fail as a belay system at extremely high force.
Using a rope intended for tree climbing with prussiks will result in a quicker arrest, which is not a terrible thing if you're falling through branches. The short lead falls encountered in tree climbing, provided you clip in to a sling around the bole or branch every 3-5', are perfectly safe using a tree rope with a little less stretch and prussik self-belay. In fact, it's just about the only approved method for industrial tree climbers.
If you're using them as ascenders, you might just buy a set of ascenders.
If you're still using a line-man's belt, you should consider getting a real tree-harness, aka saddle. They're totally cushy.
(This post was edited by Tree_wrangler on Apr 26, 2009, 8:49 PM)
|
|
|
|
|
irrational
Apr 27, 2009, 12:13 AM
Post #4 of 14
(5521 views)
Shortcut
Registered: Jul 20, 2008
Posts: 35
|
i would defiantly not use a prussik to take a fall on a static arborist line even more so on a SRT system. You will melt the cord to the rope. Best bet is to get a real tree climbing saddle and use a DRT system and a lanyard. Check out http://www.sherrilltree.com/Learning-Center/Knots for some information on the knots and systems used. Also make sure you know your tree species / biology so you can spot weak / bad attachment points and decay columns. We cleaned up a 120 DBH maple that was hollow the other day its tricky to see some times.
--IM
|
|
|
|
|
Adk
Apr 27, 2009, 12:32 AM
Post #5 of 14
(5510 views)
Shortcut
Registered: Dec 2, 2006
Posts: 1085
|
Big maple that was!!!
|
|
|
|
|
Tree_wrangler
Apr 27, 2009, 2:11 AM
Post #6 of 14
(5465 views)
Shortcut
Registered: Feb 8, 2007
Posts: 403
|
arborists lines are not static.
|
|
|
|
|
irrational
Apr 27, 2009, 11:48 PM
Post #7 of 14
(5386 views)
Shortcut
Registered: Jul 20, 2008
Posts: 35
|
i don't know what you climb on but i climb on velocity.
at 10% of its breaking strength 2.5% elongation
samsons static high angle rescue rope
at 10% of its breaking strength 3.2% elongation
sounds pretty static to me :D
|
|
|
|
|
Tree_wrangler
Apr 28, 2009, 1:02 AM
Post #8 of 14
(5359 views)
Shortcut
Registered: Feb 8, 2007
Posts: 403
|
Not as static as you'd think. I'm using a blue streak, or, a little more regularly, a shorter section of fully dynamic rope.
I've fallen on lanyards tended by prussiks and blue-streak+prussic. Both are fully ANSI approved, and have never failed in arborist settings, either in field or in the ANSI testing that validated their use.
If I was caught using a clove-hitch self belay, or my silent partner as a belay device, I'd have my certification jerked, despite them being UIAA approved.
|
|
|
|
|
Urban_Cowboy
Apr 28, 2009, 6:34 AM
Post #9 of 14
(5332 views)
Shortcut
Registered: Feb 3, 2009
Posts: 219
|
Tree_wrangler wrote: arborists lines are not static.
The "Arbor Master Series" on www.sherrilltree.com lists them as Elongation : 2.2% @ 540 lbs, I would consider that a static rope, versus the ~30% elogation of of a dynamic.
|
|
|
|
|
irrational
Apr 28, 2009, 1:17 PM
Post #10 of 14
(5280 views)
Shortcut
Registered: Jul 20, 2008
Posts: 35
|
ya but thats different then taking a 3-5 foot fall on a single line held by a prussik with little or any dynamic absorption by the rope. I'm going to say somewere between 700lbs - 1200lbs of peak force and you'll have welded the two together.
and many a monday morning i miss the death roll over a limb and end up falling on my lanyard like a chump 
-IM
|
|
|
|
|
Tree_wrangler
Apr 28, 2009, 1:32 PM
Post #11 of 14
(5274 views)
Shortcut
Registered: Feb 8, 2007
Posts: 403
|
In reply to: The "Arbor Master Series" on www.sherrilltree.com lists them as Elongation : 2.2% @ 540 lbs, I would consider that a static rope, versus the ~30% elogation of of a dynamic.
You've mixed up "dynamic elongation" with "static elongation" "static elongation" of your rock climbing rope is between 6.5-8.5%, give or take.
My arborist rope is about 3.2%, and the "static" line I use at work is about 0.7%. Both of these are "static" by UIAA definition, but are not the same in practice. The arborist lines are designed for short falls, under 6' by industrial standard.
Although "irrational" is right. Any really good force, and some welding would occur, which would result in a replaced rope at the "company's" expense.
|
|
|
|
|
Urban_Cowboy
Apr 28, 2009, 10:15 PM
Post #12 of 14
(5223 views)
Shortcut
Registered: Feb 3, 2009
Posts: 219
|
Static ropes, according to U.S. Cordage Institute Standards, should offer less than 6% stretch at 10% of their minimum breaking strength.
My dynamic rope is around 7% for a static elongation, my work rope is less than 1%. I guess my point is that at 2% elongation for a 500+lbs force is still a long way from being a dynamic rope. Although, I don't have an arborist rope, so I'm only going off of what I've read...I work on towers for a living, and climb rock for fun.
|
|
|
|
|
majid_sabet
Apr 28, 2009, 10:56 PM
Post #13 of 14
(5201 views)
Shortcut
Registered: Dec 13, 2002
Posts: 8390
|
irrational wrote: i would defiantly not use a prussik to take a fall on a static arborist line even more so on a SRT system. You will melt the cord to the rope. Best bet is to get a real tree climbing saddle and use a DRT system and a lanyard. Check out http://www.sherrilltree.com/Learning-Center/Knots for some information on the knots and systems used. Also make sure you know your tree species / biology so you can spot weak / bad attachment points and decay columns. We cleaned up a 120 DBH maple that was hollow the other day its tricky to see some times. --IM
it will melt the rope but it will not cut it. You do the same with any other device, you will end up 5 feet under dirt
|
|
|
|
|
Terry2124
May 1, 2009, 2:47 AM
Post #14 of 14
(5077 views)
Shortcut
Registered: Feb 22, 2009
Posts: 223
|
majid_sabet wrote: irrational wrote: i would defiantly not use a prussik to take a fall on a static arborist line even more so on a SRT system. You will melt the cord to the rope. Best bet is to get a real tree climbing saddle and use a DRT system and a lanyard. Check out http://www.sherrilltree.com/Learning-Center/Knots for some information on the knots and systems used. Also make sure you know your tree species / biology so you can spot weak / bad attachment points and decay columns. We cleaned up a 120 DBH maple that was hollow the other day its tricky to see some times. --IM it will melt the rope but it will not cut it. You do the same with any other device, you will end up 5 feet under dirt
That's right, it won't cut the rope
|
|
|
|
|
|
