rbtree
Addicted to ArboristSite
Mike,
Ha, can't sneak anything by ya.
Give it a break.... there is absolutely NO reason to guy a fir when zipping branches...period! (Unless there are structural defects, which are very rare in fir, even horribly topped ones.) Besides, we were hand tensioning the line. A car was in the way of our only possible anchor point. The guys were barely able to get the line tight enuf to clear the plants underneath. I had the zip attachments out as far as I could reach and lower line tied near the butts to allow for a fairly level aspect on the branches to be kept. When I came out so i could shoot pics, the car was gone, so we set up Z pulleys so John could handle the now smaller stuff by himself.
Alternatively, we have used the chipper winch, and a pick up for raising and/or turning branches, as a stronger and quicker option than a Z pulley. Maintaining a proper amount of zip line bight is key in lifting, and movement required at the movable anchor. These techniques work fine without guys, as long as finesse (read good communication) is used, and the tree is many times stronger than the loads being applied. this is always true with a big fir or hemlock, as the load is rarely more than a hundred pounds, before figuring multiplication of force from the tension applied. (Recently, I jumared 70 feet into an ivy covered fir just to lower two huge limbs over a house. They were 7-9" in diameter and 35 feet long, mighty huge for a never topped fir. So I'd reckon they weighed 300 lb each or more.)
And, no, we just free dropped the smaller high branches, then lowered the top. We never dump tops or wood onto the speedline, we know much better than to do that! Also, 72 KV lines were five feet from the high branch tips, so technically we were illegal there.
Ha, can't sneak anything by ya.
Give it a break.... there is absolutely NO reason to guy a fir when zipping branches...period! (Unless there are structural defects, which are very rare in fir, even horribly topped ones.) Besides, we were hand tensioning the line. A car was in the way of our only possible anchor point. The guys were barely able to get the line tight enuf to clear the plants underneath. I had the zip attachments out as far as I could reach and lower line tied near the butts to allow for a fairly level aspect on the branches to be kept. When I came out so i could shoot pics, the car was gone, so we set up Z pulleys so John could handle the now smaller stuff by himself.
Alternatively, we have used the chipper winch, and a pick up for raising and/or turning branches, as a stronger and quicker option than a Z pulley. Maintaining a proper amount of zip line bight is key in lifting, and movement required at the movable anchor. These techniques work fine without guys, as long as finesse (read good communication) is used, and the tree is many times stronger than the loads being applied. this is always true with a big fir or hemlock, as the load is rarely more than a hundred pounds, before figuring multiplication of force from the tension applied. (Recently, I jumared 70 feet into an ivy covered fir just to lower two huge limbs over a house. They were 7-9" in diameter and 35 feet long, mighty huge for a never topped fir. So I'd reckon they weighed 300 lb each or more.)
And, no, we just free dropped the smaller high branches, then lowered the top. We never dump tops or wood onto the speedline, we know much better than to do that! Also, 72 KV lines were five feet from the high branch tips, so technically we were illegal there.
