New to me way of chocking a log

[No_Bivy]

I used to that.....and it's impossible to keep pics from flipping. Spider legs save time since you can balance much larger picks.
Our set up is a 17ton bow shackle with 5 legs from 12 to 40. Climber a rides and rigs the lowers off. 3/4 double braid . Usually a clove hitch or cow hitch to tie.

I hear the single choker thing all the time......but when a skeptic sees it in action....they quickly turn to believer. Many off my comp now use them because crane spilled the beans about it.....not like its a secret anyway, but it sure is a lot safer and faster

That sycamore required three hours of flight time

 

[woodworkingboy]

Spider legs in use here, but a different setup. Three long lengths spliced into an eye that goes over the hook. No adjustment capability on the lengths, that gets done on each leg by pulling tight against the hook and taking a turn around the pick where you want then looping the loose end over the standing part and using a shackle attached to a spliced eye on the end to tie off. Every leg gets pulled up tight that way and tied off. Probably takes a llittle longer than the adjustable lengths type, but it is giving six points of attachment really, and works very well to balance the load.

 

[No_Bivy]

Got a pic of that?

 

[woodworkingboy]

I'll try to draw one, John, or rig something up and take a photo.

 

[PCTREE]

I would like to see it too

 

[SouthSoundTree-]

Me three

 

[woodworkingboy]

I scabbed this photo together today to try and show the spider leg method I wanted to describe, ha, don't laugh. I only used one rope in the photo, but picture two or three of these lengths of 5/8" three strand, all spliced into an eye on each end, the larger eye over the hook and the smaller for the shackle. The loop over the standing part at the upper connection is how the length gets pulled tight against the hook, then fastened below. Obviously you can fasten the lower end anywhere that you like, it doesn't have to be on the main part of the pick, though often it seems like a good spot. I wouldn't insult you guys by trying to offer techniques, but this method seems simple and effective and has worked very well for a number of years that I have seen it used and used it myself. The upper turn around the limb is ideally done under a branch union if possible, but slip has never seemed to be a problem. Some guys like to tie off the lower end rather than use a shackle, giving some more leeway in eliminating slack between the upper connection and the lower tie off point. Also, some guys like to have one leg made longer in a two or three rope system. My current ones are around twelve feet long per rope. I've never used chains with this method, but why not?

Just to add, when running the climbing line through the hook as well, I hang an oval steel ring off of it before putting on the 3 strand, running the climbing line through the ring prevents interference from the rigging lines.

I'd call it a proven method, but I'm interested in seeing what you make of it.

 

[FireFighterZero]

Thats pretty cool Jay.

It does pain me somewhat that I have been here about a year and I dont have the foggiest what you are on about.

Not your fault for sure! I did file a chain the other day that turned out pretty well.

 

[SouthSoundTree-]

Seems like the a variation on the theme. Seems like you could just tie the sling to the right length and skip the big shackle and trying to use up the excess rope, or tie-in lower than you want. If the upper redirect breaks, you lose your tension, shocking the other legs, but it helps to keep it upright with a high redirect, with a low final anchor point. If the rope is pretty straight, rather than strongly bent at the upper half-hitch, it would be less likely to break. A marl would hold the piece if it broke.

 

[GrappleYarder]

Seems like you could just tie the sling to the right length...

I imagine the issue is, as with us here in Canada, that knots are not allowed in crane work. That's why the chains, with the adjusters, are an attractive option for having an adjustable sling length. People here also work around this by having a main static sling and then use a spider-leg as a supplementary balancing line. But not all crane ops will go for this.

 

[MasterBlaster]

I have no idea what's going on in Jay's pic.

?

 

[SouthSoundTree-]

Sounds like its basically a spider leg set up with a half hitch above the main rigging attachment point, where you have to use a clevis and eye, over being able to tie the anchor point termination.

Seems like you could cow hitch it at the desired main termination point, like you're tying a more 'standard' spider leg set-up, then snug the clevis up below that, if that's legal.




I use a small crane and have small landing zones typically, so (along with too many irons in the fire) I haven't explored SLs, yet.

 

[woodworkingboy]

Sean, I wouldn't over think it. In the set up that I showed, the lower connection helps to cary the load when the hook snugs up tight, breakage at the half hitch point has not at all proven to be a concern. I think that's the beauty of it. With chains, I just wonder if you can pul up tight at the half hitch all the way down to the lower connection, or would it bite at the hitch?

MB, where the upper eye goes over my drill press handle, is where the hook would be. With two or three of those ropes being used at different points in the same way, it is spreading and balancing the load. The pole sticking out sideways is meant to be a limb. It's the principle behind spider leg use.

 

[No_Bivy]

If you clove or cow hitch straight to the rigging point they are infinitely adjustable.

 

[woodworkingboy]

John, you see no advantage to having two points of attachment per leg, like I tried to illustrate?

 

[cory]

I think a small but key point is that is a marl, not a half hitch.

 

[No_Bivy]

Not really. Am I missing something?
Seems like only one is gonna take the load. If five legs are used...all five would be independent.

Also seems like shackle defeats pulse of being adjustable.

 

[SouthSoundTree-]

Jay, is the loading meant to be at the half hitch, below a crotch, with the choking shackle/eye used to eat up the tail? Is the choking shackle termination required to be legally compliant?

 

[Reddog]

For folks using all spider legs in a lift.

How are you getting past this requirement?

1926.251(d)(7)

Employers must use natural- and synthetic-fiber rope slings that have permanently affixed and legible identification markings that state the rated capacity for the type(s) of hitch(es) used and the angle upon which it is based, type of fiber material, and the number of legs if more than one.

Source: https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10686

 

[No_Bivy]

Because it is not a sling.....you have to clearly state that. It is rope.......since it is rope you need to know tensile strength and working load. 3/4 double braid is 20000.... So 2000 per leg... 5 legs - 10000 in theroy I guess.

If OSHA rolls up and you call it a sling you might be in trouble.

Sling...girthed..choked ,shackled

Rope...tied

I could be wrong

 

[Jake Andrews]

So all 5 spider legs are from the same piece of rope, or 5 different ropes?

 

[woodworkingboy]

Cory, yes a marl, and a key point, as you say. Thanks for the correction.

Sean, there is no legality issue one way or another in these parts, to my knowledge.

To my mind, the upper marl acts as a positioning/balance connection, but the reliance on weight carrying security for the most part, is the shackle connection below, or a knot as a tie off for those that prefer that method. The two connections per rope work in unison in that regard. With a cow hitch above, the additional connection below become superfluous. Two connections per with the lower one on larger wood if thought to be a plus, seems like a very secure way to go.

Jake, talking about two or three ropes.

 

[cory]

Its rare a TH vet needs correction

 

[woodworkingboy]

I'm an exception, I guess. It was a half hitch by default, i couldn't think of the word, "marl".

 

[cory]

As the TreeSpyder (I think that was his sn) said back in the day, if you remove what they are tied on and pull the rope, a marl disappears, a half hitch becomes an overhand knot.