Portawrap options

Back of heavy truck for lifting/pretightening lighter loads.

Any heavy duty anchor (base of 2' diameter pipe for billboards etc.)

Imitating Porty in tree with stob arraingements.
 
Nick, just a thought- If you use the P-A-Wrap in the tree in place of a pulley (for example) you could reduce the loads displaced on that point by 1/2. It might be a bit more difficult to handle the friction on the way up until you remove the wraps. You may have to get more creative with how you use your rigging as well. One negative (other than having to run the ropes in the tree and try to judge the heights from above looking down) would be the possibilty of the rope peeling off of the unit. Unless ofcourse you have the latest model from Buck. that would contain the rope.
 
Hi, guys;

The suggestion for using the p-a-w at the rigging point is a good suggestion because we create a higher margin of safety in the tree anytime we reduce rigging point loads. Wraps taken on a p-a-w can add to the frictional force through each turn of rope around the cylinder.

A thought to possibly compliment the suggestion: take the maximum amount of wraps which will still allow one to lower the load, then use a munter hitch to lock off the load. The force at the rigging point will be more than 1, but less than 2.

One could also attach the p-a-w to the load which in turn could reduce the force at the rigging point to 1.
The problem here is figuring a way to tie off the fall of the rope to the p-a-w so that no tension is needed to keep the load from running. I made a friend at the I.S.A. web board, Isaac, who happened to be an eagle scout. I proposed a challenge to him to find a knot or hitch which could be tied to a friction device that could be undone from the ground but strong enough to keep the rope from running while the rope was being loaded. He came up with a knot in less than a night, maybe an hour, that the friction in the knot could be adjusted by how tight the knot was initially tied. I never came across a situation where I could actually test this knot/hitch in the field so I don't know how well it would work. It was a clever solution to a problem from a clever guy. Such a knot/hitch is needed for this type of application.

Some advantages to attaching the p-a-w to the load is more rope can be put into the rigging system. A series of pullies can be incorporated into the rigging system to raise the swl of the rigging lines. Some disadvantages to such a system are once tension is put into the line from the p-a-w to the ground, the force at the rigging point will raise and so will tension in the rigging line. Tangling of the rigging line in the load is always a concern. In contrast, the initial loading of the rigging and rigging point is where we need the most control.

I have used a munter hitch on the load in conjunction with pullies to reduce line tension and rigging point forces. I have not reached reducing line tension to the weight of the load.

Joe
 
Here are some of the places that I've mounted a friction device, FD:

*In the tree as a rigging point. This has been discussed here already. With this setup, I can eliminate about one half to a full person on a job. That means that a three person crew can work almost like four. The climber sets the rope on the limb and the groundie holds the rope until the limb is cut and ready to lower. then the climber takes the rope to lower. Groundie doesn't need to hold the rope with a hand and work the limb with the other. Hence, the partial gain. After the limb is on the ground, the climber takes the other end of the line and ties off the next limb. The atv is there to haul out the cut limb. Then the groundie pulls up the rope and repeats the process.

*Instead of mounting the FD at the base of the tree, run the rope through a pulley/redirect at the base and set the FD at the base of another tree. This keeps the ground crew out from under the drop zone. I also find it easier to manage the ropes when they come in horizontally.

*I built a t-shaped bollard out of four inch diameter tubing. this is welded onto a rectangular tube that slips over the fork of my 6k# front end loader. The Waldon can be moved around for the best location. If the tree is strong enough we have used the Waldon to lift limbs just like a rigging device. This is a dicey operation because it would be very easy to overload the anchor point and pull the tree apart.

*The same device has a two inch reciever slider on the bottom to go into any reviever hitch.

*Many people mount bollards on the sides of flatbeds.

*There is a smaller t-bollard on the front of my atv for the same reason as the Waldon. Just smaller loads. We use the quad to pull over trees on occasion.
 
Thanks, guys. The reason I asked is that I was doing a removal of a Silver Maple the last week and we put the PW on the outrigger of the bucket. I was on of the climbers (there were two) and we did the high parts of the tree that the bucket couldn't reach. At that time, the rope was wrapped around the outrigger to give the friction to lower loads (this crew had never used a portawrap before). After I got on the ground, I looked for a place and saw that the only option was on the outrigger, and the base of the tree. The outrigger had the convenience of being smaller (easier to connect to) and a bit further out of the drop zone. I thought since they were wrapping the rope around this same outrigger before, that it might work to just put the PW there. I did, and had other guys work the rope on the first few heavy loads to see if it moved or shook anything. There were no negative repercussions, so we proceeded with the rest of the removal, with one eye always on that out rigger. It went well, and we did the same thing on the removal of a 115' double cottonwood. We dropped some super huge pieces of wood there, with no NOTICEABLE ill effects.

About the PW in the tree, I like the idea and I see the convenience, but I don't know about hauling that thing around the tree. I'll have to put some thought into it.

love
nick
 
Tom's suggestion of spacing ground pilots away from overhead hazards with pulley is very good (of course); as long as load doesn't slam onto line from pulley to Porty. If you don't do that redirect to the base, and just go at an angle to porty on a tree across yard, you would be leveraging pull across on upper rig support; this would be at it's weak axis of support, not running down the columnar strength of the vertical spar with stress of line. Also, as with any 2 spread points, gives a another great sweating in point for pretightening; this one very ground accessible, and could easily be gotten to center, for maximum leveraged pretightening, or sometimes even pulling around ,as hinge walks close to folding, forcing more hinge strength; very powerful strategy, but ya can't let it shock ya!

Also any redirect point needs more support, and linking than final point (ending at Porty, or floating Porty, low redirect to Porty, versus porty position. for a redirect point has 2 legs of pull on it; whereas end point only has one. So low redirect to Porty, would get stronger Sling and hardware than ending Porty position, just as overhead pulley (to Porty on ground) would be more beefy than Porty position.


Overhead frictional redirect (non pulley); has some tradeoffs as anything. If shock loading, gives less rubberband to take the shock, more chance of failure. But if hinging down and pretightening line with that action before tearoff, lessens greatly (depending on ratio of load and control leg lengths) the amount of line that such self pretightening needs to be maximum. i thinx that can make all the difference in the world, besides lower support loads from lessened control leg load on support. This passive resistance can give much wider and dynamic choices for rigging. To the point of, if set right, and forcing load to pit against itself, more length and weight, makes it more powerful rig, rather than werking against ya!


Or something like that!

IMLHO
 
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