Port-a-wrap attachment

Ax-Man

Don't make me chop you
Joined
Feb 4, 2006
Messages
705
Location
N.E. Illinois
I have been taking advantage of one of the guys that helps me out with his new Blackberry camera phone that takes some very nice pictures.

I made this little homemade set-up for a porty out of some odds and ends. I like it for doing light,medium duty type lowering using a porta-a-wrap. It is fashioned similar to a clock hitch which is my prefered method over a whoopie sling. As safety of sort you can run the tail of the rope back through the ring and timber hitch back onto itself.

For me this is a quick and easy set-up, cinches up nice and tight with that prussik with very little slop. It also works great IMO for a 5 to 1 on a neighboring tree to pull a spar over if that is all you have to work with or as quick redirect for a pulley.

I know with all the tensile strength reducing knots this isn't an ideal attachment for slam dunking blocks of wood but I have loaded this some good sized limbs for lowering and it has held up good. Much better than I thought it would.

I just thought I would throw this out on the table and see what kind of feedback I get.
 

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I tend to go back to my rigger roots because I really don't claim to be a tree man .As such I improvise with log chains ,heavy screw shackles and the like to make do should the need arise for such things .

They get the job done but I imagine do to the fact everything is heavy and awkward it would not be a good practice for production types of tree dissassembly .
 
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  • #5
Now that is different , never seen or heard of that one. Goes to show there are more than one way to skin a cat. Good deal Butch.
 
Here are a few pics. It looks crazy but it'll snug up nice and tight to the tree and can be easily tied/untied. The last pic is what I'll do if I want additional support and/or just to get the rest of the rope outta the way.
 

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  • #9
The biner just goes along with the porty. The porty is in our boom trucket most of the time. I have several rig points set-up on the truck mostly lifting eyes either welded or bolted to the truck bed for the porta-a-wrap. The biner is the only way to attach it.

Steel biner, with screw gate, 70 kn. I think. I like this much better than the locking ones. The reason for such a heavy biner is because we tension the heck out of a lowering line sometimes before cutting a limb then lock the rope off. While the limb is being cut I will then pull on the tensioned line to help get the limb to go in the direction we need it to. After the limb is free I'll let go of the rope. The biner and porty have be able to get take some good jolts when doing this after the slack is played out. I think Tree Spider or Kenny refers to this method as swiggin if memory seves me right.
 
You guys need to get a Hobbs or a GRCS, then you will have a much easier way to: " tension the heck out of the lowering line"
 
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  • #11
Stig,:lol::lol: Your right. We have one of those also. For the smaller trees in a not so confined space the porty is just so much easier to use. Makes a good quickie friction brake without all the set-up and take down of a GRCS.
 
Just kidding you.
I use a Porta-wrap too, when setting up the Hobbs is too much of a bother.
 
Butch, can you take some better pics with measurements for your porty????
I'd like to get one made

Thanks.

Cary
 
Nice pics and porty, MB. Is that home made?
 
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  • #17
On both of those setups, what keeps it from slipping up the tree trunk?

Friction from the bark plays somewhat of role to keep it from slipping. When the porty is loaded the attachment point will pull upwards a little, the rope has somewhat of a choking effect on the stem when the porty gets loaded. Never have had a porty slide right up a stem.

Even in pre GRCS days and Whoopie sling days we would just take a section of bull rope and fashion a clock hitch around the base of the tree without much upward movement of the port-a-wrap. When we got to the big stuff especially if we were blocking down chunks we would have to retighten the hitch but it never slipped up the trunk.
 
Well, I thought I was doing it the accepted way...I just use a cow hitch backed by two half hitches, or a timber hitch if the sling is too short for a cow.

No?
 
Well, I thought I was doing it the accepted way...I just use a cow hitch backed by two half hitches, or a timber hitch if the sling is too short for a cow.

No?

I think this is the best way. Maybe even the most common way, as well.

For the first setup, one of the first rules of rigging is to use as few separate pieces as possible. That setup has a few more pieces than it needs, in my opinion.

love
nick
 
I use a timber hitch myself. Out of curiosity, does that prusik on there ever slip and let the sling lengthen when it gets shock loaded? I remember reading somewhere that a prusik will slip around 1500 - 2000 lbs.
 
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  • #24
Bounce, I am assuming your question is directed to me. The prussik is a quickie adjuster nothing more. I find it easier to use that than winding rope around the base of a tree. The prussik and snap will hold a decent load on it's own because I have tried it on stuff where I thought it would break and hasn't slipped. As a safety or back up for the prussik and snap I will take the tail of the rope pass it through that ring and tie it back onto itself similar to the way a timber hitch is tied. The set-up is fashioned more like a clock hitch.

I would never trust that set-up for heavy shock loading, too many knots in the system and it's too light for heavy work. I made it for the lighter duty work mostly for simple lowering using a port-a-wrap. I like this set-up for that because all I have to do is stand in front of where the ring needs to be, cinch the ring up tight with the prussik and snap and if I need to tie the tail like I described I don't need to move to much around the tree or fumble around trying to reach around the tree with my other hand fishing for a rope. I myself never cared too much for a timber hitch using a port-a-wrap. It would be the hitch of choice or a clock hitch if I was shock loading the rope though.

I don't know if a prussik would slip at 1500 -2000 lbs or not from shock loading as I have never done it persay. I have used prussik hitches as adjusters made out of 1/2 tennex on rope to pull logs out of ditches or up hill with with our boom. Never had a prussik slip on a direct pull like that even though the fibers stretch and compress and darn near fuse themselves together.
 
The way Burnham speaks of pulls inline with the rope, then bends it some. But, these other pix favour to pull across the rope's longest axis; i would think leveraging it. Now, each of those lines thru eye does offer 2 legs (per Turn) of support compaired to Burnham's 1; but still he is pulling inline, not across the rope as a device. One mrMaas would tend to disagree with me though (partially jest from habit), with these 'Clock Hitch' type arrangements.

i think olds-cool hear is best; with a news-cool long eye that places the joint/ deformation in the line (of the splice, bowline etc.) beyond the reach of the rawest load and impacts (after those forces are buffered some by choke of rope by Turn around Standing and bark friction). So, then the eye offers 2 legs of support, that doesn't become 1 before impacts etc. Notice we specifically wouldn't want to bend the stiff part of the splice (or Bowline) as part of the Turn around Standing Line tension.

But then too, reaching back further i like a Round Turn instead of a single Turn around the load bearing Standing; like in ABoK #1669. Then on to a Cow, or if not enough line, Timber as pictured, that is then locked off as pre-scribed. This effect (one round Turn around Standing being preferable to single Turn) is seen in the Scaffold/Dbl.Noose/Dbl.FisherPerson's and others. It seems 1 Turn seems to destabilize and leverage the load bearing Standing by sudden deformation, and 2/Round Turn does same; - but over a longer/ less impacting distance(?). Note too, that the effect is lessened or even lost in tests of Dble. Noose on krabs, if the line goes around the krab (tree?) more than 1 Turn (before the Round Turn around Standing); like the lessened tension in that part of the line from the extra friction around device was not enough to provide the 'fortifying' effect. (note also in the Timber type hitches, the farther opposite the Standing you lace under the Turn around the tree, the more secure).

abokTimbers.JPG
 
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