why spider legs?

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...i see the need for spiders when working in very tight horizontal planes...

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I'm with you with that. There is a time and a place for certain methods.

And for those who don't think it is necessary for horizontal limbs(that are above wires, structures, or whatever) they are simply being stubborn.
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they are simply being stubborn.
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EXACTLY, but i don't know why one would be stubborn about something like that.
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One sling on each side of the fork would have caused excesssive movment.if one sling was on either side of the union, meaning to the right on the smaller wood it would have been butt heavy. If one sling was on one of the limbs to the right of the union and one on the bigger wood it would flip untill center mass was under the hook.

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The point is to have the weight under the hook so it won't flip.

Nobody understands me in this forum, maybe I should find a crane operators forum so people know what I'm talking about.
 
I understand you ctm you have to realize they are the crane operator and the climber. Whereas if you have a couple of guys that work well together you can drift these picks away from obstacle or stand them up with a hinge simultaniously as the cut is being made. Tough to run a saw and a remote at the same time. I also have never used more than two slings in any situation. It works well obviously, i just have the need yet, or the time.
 
If you don't want the piece to move left or right, whether it's two slings or spider legs, the ball has to be centered. Meaning the weight has to be centered on each side of the ball. On a forked limb, if only one side of the fork is supported, the side not supported will rotate down. Spider legs will stop this. If it were me, I would support the butt and both sides of the fork. Put a little tension on it along with a little side pull to the right and give it a snip. But what do I know.
 
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I understand you ctm you have to realize they are the crane operator and the climber. Whereas if you have a couple of guys that work well together you can drift these picks away from obstacle or stand them up with a hinge simultaniously as the cut is being made. Tough to run a saw and a remote at the same time. I also have never used more than two slings in any situation. It works well obviously, i just have the need yet, or the time.

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I'm not talking about hingeing or drifting. I am talking about placing slings on a limb cutting it and having it just sit there and not move until the crane operator is signaled, much like running a remote. My point is, is that spider legs are not the answer, proper judgement is.

Often times I am rigging and cutting out of the view of the operator so he is not able to drift anything away from me or tell me where the CofG is and that is whats important, not how many legs you use.
 
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I do not see a hook?

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One sling on each side of the fork would have caused excesssive movment.if one sling was on either side of the union, meaning to the right on the smaller wood it would have been butt heavy. If one sling was on one of the limbs to the right of the union and one on the bigger wood it would flip untill center mass was under the hook.

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I am not saying on either side of the union, I said under the hook (you have to use your imagination, he didn't get the hook in the photo) on each branch with the Center of <u>Gravity</u> already under the hook. If the pic didn't move after the cut then the CofG was perfectly under the hook.

Even with spider legs if the hook is not over the CofG then after the cut it will move.

Once again the tecnique you use is up to you. All rigging techniques require the hook to be directly over the CofG when making the pick otherwise it will move until it is, just like you said.
 

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Here is Marks photo edited, the yellow lines are where he placed his slings, the red line is the CofG where the slings could be placed and the result would be the same.

He didn't tell us how much it weighed so I made up a number to show my point.

I think He did a very good job and I don't care how he slung it, the reason it didn't move is because his judgement of where to have the hook, right over the CofG.
 

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Having the hook under the COG is standard. The point is with multiple slings you will have predictable results. Using 1 sling and hoping you are correct on placement may not be good advice if there are obsticles like utilities.If one sling was placed as you showed in the last pick the load could rotate contacting obsticles. Like others have said this technique has a place. May not be for every cut or every tree but it has it's place and Marks posting is an ideal cut for it.
 
I'm not trying to say use just one sling. What I am trying to say is that no matter how many slings you use if you do not have the hook over the Cof G there will be movement.

Yes if you only have one sling and you are off with your placement that sling acts as an axis, however so does the hook with multiple slings. If you are way off on the placement the pick may come vertical after the cut, but generally it will only move the same amount it would with multiple legs. If you were way off with spider legs it may become close to vertical too.

Since I can tell that I am coming off as critizing everybody (although I am not intending to) I'll offer some advice to hone your skills if you get a lot of crane work. Try to use the fewest number of slings in non-critical situations and all of your picks will improve even your spiderlegged ones.
 
I get your point. If the crane is not over center mass you always have movment for sure. Owning a crane we perfer to limit movment as much as possiable on every pick. Seems good work practice for the company and the employees.
 
Yes that is very good practice and like I said if you practice in non-critical situations then when you are over live power or houses your not soley relying on spider legs to minimize movement, you can remove movement completely from the equation.
 
classictruck,

just to let you know, i'm glad you are on the forum as I am happy to read most of the people on this forum, and if people think you are just attacking or critising, too bad for them. I get it all the time. Don't get too frustrated and way to go not just giving up with what you were trying to say.
 
Sorry ive been away. I agree with what you say judging end for end. but that is saying both ends are balanced the same. I guarantee if I had hooked it at the point in your illustration it would not flop end for en but it would have rolle since one side of the union was higher off the ground than the other. So end for end yes but inthat situation not side for side.
 
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Thanks, each time we talk about crane rigging on this forum it reminds me about the banter between BB and JOMOCO on chipper safety.

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Hey I resemble that comment!

One sided discussions with Ignorant (capitol I) fools sucks!

this discussion is nowhere near that failure of a topic. The people in this thread are conversating, understanding, and hopefully learning from each other.
 
ctm are ya' saying spiderlegs have no place and they're just silly? even after several experienced arb/opps have tried to get ya' to at least consider them for some situations?
 
No thats not what I'm saying, I will say that I don't use "spider legs" but you can use any technique you want as long as it works, what I am trying to show is the physics behind it and show that it isn't the spider legs that balance everything.

I have a very hard time communicating by typing, I find it pretty easy when I'm teaching crane rigging to other arborists.

And in reply to Allmark, I would use two slings. one on each branch where the red line is.
 
yeah a lot of us areguilty of miscommunication through typing. sometimes i'll be typing something thinking it's in a nice tone...then when i go back and read it i sound....but it just seemed like you've been dead set against spiderlegs from the start...at least that's how it sounded. Sorry if i misunderstood.
 
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