Guyline Question

[Hemlock]

When speedlining a top would it be a good idea to guyline the spar against the direction of pull? This technique is common for rigging lift blocks in tail trees for high lead logging and I've seen them take alot of pull. The ones I've seen fail seemed to have been under much greater pressures than what a snubbed up top would put on them. I wonder if you could eliminate the tree whipping around on you if your groundman messed up and make it safer? Maybe even tie it back twice?

 

[Kneejerk Bombas]

http://arboristsite.com/showthread.php?s=&threadid=6470

 

[TheTreeSpyder]

If i can, i halfhitch around where i want that leg to pull on (for same kind of tensions as DWT); then continue on with line around another support,then back to the halh hitch (this gives more strength and is retreiveable lacing.

i try to place that end higher than the pull for better leveraged support. i think the best angle to run the line from the halfhitch to the support directly behind, is to plot the angle the load will have most pull at, and continue that support line up from there. This places the pull of the support in the direct most leveraged position against the hardest loadpull/line leveragd angle. For it is not only the super leveraged loads that we fight; many times the highest loads are pulling at the weakest angle (across on a vertical branch) on the support. Fortification can be given against the pull, and is most effective in supporting, by being set in the most resistant angle of pull(180o from the pull of the load) IMLHO

Then, push the first branch towards the second, while also pulling the second (bracing branch) back towards the first with the 2/1 (pull from brace to half hitch), sneak slack through half hitch; sweat in (using same leveraged numbers as speedline to tighten)tighten super hard, to fight superloading when load pulls on leveraged angle of line.

This gives 2 legs of tightened support, 1 leg (at least) in best position against worst pull, possibly 1 leg at higher leverage of pull on support than load; in a retrievable formation. once i pot a stick between both supporting legs and twisted tight; then locked the stick from unwinding with sling, carabiner set.


Dave's DWT calculator at TreeB*zz, can also be used for calculating angle's of leveraged pull on speed lines. The (t) in the formulae gives line tension at a given angle of dip in line, under a certain load's force. It shows that a speedline witha dip of 150o to have a line tension, therefore support pull of ~2x the load force. For 160o, ~3x; and 170o,~6x respectively. So the maximum pull at 170o, is also pulling across spar in leveraged angle, not down it's columnar strength.

 

[Hemlock]

Thanks Mike, Spyder. WOW! I mean really, WOW! I'm sitting here wondering how the heck I got by rigging tail trees all those years without knowing all that mathematics stuff. I guess it just sounds more complicated when you write it down and a helluva lot more important when yer tied to the tree instead of watching it from a safe distance. You guys really know your riggin'.
A coupla' things sounded familiar though. That tensioning device you used in the canopy spyder is called a "twister" in the woods and is made by wrapping 3/8 strawline cable round 2 or more trees and tightening with a stout stick called a twister stick and poked into the ground. Usually tried to twist her back twice quartering off the backside of the angle of pull. Sometimes it looked like a crows foot from above with three twisters.
According to Hoyle (OSHA) you're supposed to timberhitch your guylines up in the tree but if I just wanted to make sure the tree didn't pull for insurance I took the bight and shackled it to a strap or choker with a passblock. I anchored one leg to a stump and used a come along to tighten up the other end at another stump before hitching it. I know it maybe a shortcut but it allowed the tree to move laterally a little bit and balance out the pull on both back quarter guys. These trees were also conifers and were alot more forgiving than hardwoods. We never hung on maples or alders unless to pull a bigger line out.
As far as what the trees could handle, Alot. I was running 2000' more or less of 1" cable just for a haulback/tensioning line connected to a ton of butt rigging connected to a turn of saw logs that were being pulled in by 1000 ft more or less 1 1/4 mainline to a tower that was held up by 6 or 7 1 1/4" guys. The blocks we hung with were 15 or 17" sheave Young blocks and hung in the tree by 3/4 to 1" cable straps (roundturn) and run back through two or three more 17" blocks to complete the circuit. This is just an everyday type highlead system and depending on the job the equipment and lines/loads can be much more.
The old timers set up was much bigger and more complicated and they added "Buckle guys" about halfway up the spar to keep it from bowing and breaking under load. I guess the only reason I mentioned this on an arborist forum is to say that I've seen rigged trees take one heckuvalot of load and do no more than quiver. I wondered if on a smaller applications using arborist rope, small rigging, and portable tailholds (anchors), with or without the aid of friction devices it would work. I think that you guys answered my question and gave me more to think about besides. BTW, anybody ever beat car axles into the ground in strategic locations for use as anchor points? They work great for light treework, pulling out stuck trucks etc.

 

[rbtree]

Yo hemlock,

Welcome to ASite..How's the snow where you are? which is where?

Nice to hear some of your logging exploits.

We'ved had innumerable discussions about speedlining, the major side loading which occurs, and the need for guying--if the part being rigged is large enough in relation to the spar to warrant it. Many similarities to high lead logging, but a lot simpler.

 

[Lumberjack]

Originally posted by rbtree
Yo hemlock,

Welcome to ASite..How's the snow where you are? which is where?

Nice to hear some of your logging exploits.

We'ved had innumerable discussions about speedlining, the major side loading which occurs, and the need for guying--if the part being rigged is large enough in relation to the spar to warrant it. Many similarities to high lead logging, but a lot simpler.

He's in Seattle with you amd others from AS.

Carl