multiple rigging points?

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beastmaster

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Today as I was SRTing throu an Oak tree I was amazed at the small dia. of some of the limbs I was using to support my self. Sharing the load using many different points wasn't a concept I was overly familiar with. My understanding of physics in general wasn't what it should of been. Srt has opened up my eyes some on several levels.
Now my dumb question; Running a line from the ground to a block puts the weight of the piece being lowered on the limb where the blocks attached, So does using several redirects(pulleys)before the primary lowing pulley reduce the weight on the limb the piece is being lowered on? So in effect you could lower a bigger(heavier)piece then the lowering limb would normally hold if you used a single pulley? Not that I want to push the envelope, but adding a bigger safety factor might be nice some times.
I hope I made enough sense that my question is understood. Thanks.
 
The important thing to remember when rigging is that if you are using a single block to lower the weight of the piece is doubled on the block. That is there is two lines going to ground one is pulling down with the weight of the wood attached and the other is holding back the same weight. Now if it is dynamically loaded (Butt hitched) that number can easily double triple etc. So When lowering big wood and it is possible I will set two blocks in different leaders. This also lessens the amount that the tree will sway and bounce. Additionally the rope coming up the tree is seperated from goong down, this keeps tangles at a minimum.

Mike
 
It is not just how much force is put on the tree, but how that force is transferred and distributed. Having a single block places takes the weight down into the spar, if you can put a redirect behind it you shift how the force is applied.

Another thing about using multiple points in the tree is that you can set up higher, which makes it less likely to shock load the system as the load comes off the cut.
 
In addition to many of the comments I absolutely agree with, and should be used in your daily routines, is also the fact that when you redirect and use a double crotch or pulleys you are opening your angle some also reducing the bend fatigue on your ropes and equipment along with the trees ability to handle more weight by dividing the weight through the crotches. Common sense with size of wood / branches you take as well. It doesnt mean you can take the hole piece because you double crotched in. remember that if you have a 200 lb piece of wood you are chunking and it falls 4 feet before it tightens on your rope and crotch, you are to add the weight plus time 4 and add the weight again. So the 200 lb piece is roughly 1200 lbs now. I have said this many times " you can always take a smaller piece " Rig safe.
 
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