How do you secure your Port A Wrap?

[Sciadopitys]

Cow hitch or timber hitch (depending on tree girth and sling length)

I worked with a couple of climbers who used to tie a clove hitch cos they claimed the bend radius was not as great as with the cow hitch and the timber hitch. They backed it up with 2 half-hiches like when ur rigging branches off. I could see their theory, but i found that the block slips down a bit too much after loading.

[Sciadopitys]

sorry misread the question - i was just on about tying the block on! sorry. I use a whoopie sling too for the portawrap!

[TreeSpyder]

The Cow Hitch is a Girth/Choke Hitch (a double Girth a Prussick), only a Cow has pull only on 1 leg. This means that the Cow has more load on that 1 leg, but also means the other leg could be weaker. But, then also the 'free' leg/ bitters should be locked down. so, a series of slings or lines could make up an anchor, best one taking the brunt of the loading impacts. If removing tree anyway, i'd make some small humboldts to bed sling/line in.

 

As far as a Clove giving less deformity/ strength loss to the Standing (Tension) Part, on a larger mount; i'd say that could be true; iff the pull was perpendicular (as opposed to inline pull on tree etc.) to the host/mount/spar. The Cow or Girth, can give varying amount of deformity by how the unloaded leg(s) bend the Standing Tension Part. In that model, the choke bending the fully loaded Standing would be less loaded than the Standing itself (up to 120 degrees bend, like pulling backwards against the choke could actually make the Standing Tension Half the choke...). But, pulls on a Clove or Cow up a tree/ inline(as opposed to perpendicular pull on tree etc.) with tree/spar/mount could very well make Clove give more deformity/weakness(?).

 

A timber with 7 turns is good, but i think half that many as well; the primary thing would more be that part of the Bitter/Tail be trapped at a convex position opposite the loading, just past halfway. Visualizing that the front of the works pulls away, and this portion pinches into (the host mount/spar/tree). Just past halfway places that trapping where it would lock into the rise at highest / most equal and opposite tension on any rotation. A fair linear round turn/spiral before is very good. 7 turns probably a little overdone, but more fairly places at least part of the bitters in this best area (just past opposite of the initiating pull). Baby Holding Bus shows turns as friction to reduce force flowing into Bitters, Then trap that reduced force under as much force as possible to secure.

 

i've done as Bodean, like the branch collar as dawging for sling to lock into. i do kinda like a Cow with a Round Turn rather than a Turn around the Standing, then lock the tail down too. A girth/Choke is likewise better with Round Turn rather than simple Turn around Standing(s). 1 Turn bends/deforms/weakens but more Turn(s) can restabilize some of that deformity (if correctly applied) like a Double or Triple Noose/Scaffold is sooooo much better than a simple Noose.

 

If using a Whoopie, i like primary loading on adjustable leg, so that primary load is on a different point each time. Then, might extend off fixed end other sling to then choke back the Whoopie loaded eye, and then adjust Whoopie, so now have larger Whoopie. Of curse if the other sling is stronger, it can take brunt of loading. But a good size Whoopie (thick with adjustmeant range of 3'), with a 3', 6',9' etc. Spanset (type) slings as add-ons can take ya far (large range of adjustability with 3' range of adjustability and 3' incremeants in slings...).

Edited November 17, 2008 by TreeSpyder