Spider legs

Mark, it's tied with a double clove. It is faster than working with a balancer. If the leg is short, it can be time consumimg pulling the excess rope thru the knot. We're working on another system that is faster. If we think it's worthy, I'll take some pics.
 

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Thanks! Im real comfortable with the clove.Its what i learned all my rigging with at first. I use it still quite a bit.I was thinking of making a shorter balancer for that reason butnow maybe ill try the spider legs. thanks for the post.
 
Very Nice!

Following the force of gravity as straight down: Lines that follow this straight down path to be inline/minimal/unleveraged ie.- same distance straight downward with gravity as length of supporting leg.

These angled lines then carry the same amount of load a longer distance, to get just as far downward from rigging point/joint; therefore are leveraged compared to a straight line by this theory.

So angled lines of spider leg carry more force/ lower SWL; also direction of pull on load is changed to a more compressing/potentially crushing angle. Spreader bars on top of loading dock loads (lines to supporting pallet under load, that run up the side of load and then angle to supporting crane hook at top), are to keep the angled lines/teepee at top from crushing the load's crates etc.
 
Nice pics Norm. A couple of questions.

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Here are some pics of the spider legs in use. These are 5/8" tenex, 20 feet long.

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So these are basically 20 foot long eye slings? What I'm envisioning is that the eye is placed on the hook and the end of the sling is then just tied to the limb so that the sling is taut. Is this right?

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it's tied with a double clove

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That's a clove, followed by another clove as a backup?

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It is faster than working with a balancer. If the leg is short, it can be time consumimg pulling the excess rope thru the knot.

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When you say '...thru the knot..' does 'the knot' refer to forming the clove(s) or a knot used to set a balancer?

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We're working on another system that is faster. If we think it's worthy, I'll take some pics.

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Sounds interesting. Let us know.
 
These spliced eyes were placed on the crane hook, but I would use a 17 ton shackle in the hook and put the eyes in the bow. This was a TCOT crew that chose to place the eyes in the hook after they checked the hook for burrs.

A double clove is a clove hitch locked with another clove hitch.

If 1 leg uses 12 feet of rope, then the remaining 8 feet has to pulled to tie the knot.

We don't have enough testing with the other system yet to know if it is safer, easier, more efficient. More crane time is needed.

Thanks.
 
Norm, what about using a high modulus fiber prussic cord with an eye? Choke the eye back with a rated shackle, adjust the prussic, presto! Either that, or just double the end of the line back and prussic it to itself like those old 2 in 1 lanyards. The first option would be better, except for the variable amount of excess tail flopping around.
 
Roger, that's a great idea. Sorta in line with what we're testing now, except for the high modulus fiber cordage. We don't want to spend the extra $ on high modulus fibers until we have tested the system with polyester fibers.
Keep the wheels turning!! /forum/images/graemlins/hypnodisk.gif
 
Why don't you just tie a 6 wrap prusik loop around a 5/8" double Braid Rope?

Hook the prusik loop, tie off one end of the double braid, run out enough rope to tie a bowline on a bite/alpine butterfly, clip a sling, adjust the prusik to the point of balance and fold it down into a 'U' shape - you now have a balancer without risk of slipping and a good bend radius. The tail of the rope can be used as a tag line to spin the branch/section.

If you want spliced strength, then a 50 foot length with a prusik loop in the centre to adjust to where you want? Quick and easy, no tails.
 
This is the adjuster. The white sling has a large eye spliced in so that I can tie a Klemheist for adjustment. The small eye is where the biner would go that attaches to the sling that's choked around the limb like Lazarus is talking about.

I've used this configuration in 2,3 and 4 leg setups. It seems important to use opposite legs when I use less than 4 to keep the load on the eye splice balanced. Even if it were a little off center I don't think that the eye splice that is used would have a chance to invert.
 

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Hey Tom
Thats a neat looking fig 8 eye splice you have in the end of your spider leg; cinches down on the shackle/krab to stop it rotating, right? And more fancy splicing for the four legged spider - neat.
 
Tom Dunlap said:
This is the adjuster. The white sling has a large eye spliced in so that I can tie a Klemheist for adjustment. The small eye is where the biner would go that attaches to the sling that's choked around the limb like Lazarus is talking about.

I've used this configuration in 2,3 and 4 leg setups. It seems important to use opposite legs when I use less than 4 to keep the load on the eye splice balanced. Even if it were a little off center I don't think that the eye splice that is used would have a chance to invert.
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Tom, do you have this sling anymore? It looks really complex, but interesting. I’d like to see how it is made and how it looks in use. Does it require all legs to be connected to load properly, or can you use just one leg?
 
oceans said:
do you have this sling anymore?
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I don't

a couple of clues from memory.

Two pieces of large [orange[ Tenex are used. One buried into the other to form the big eye. Then some Brummel-esque crossovers to lock all four legs in place and share the load.

I used it as a 2, 3, 4 leg spider. The orange legs were about 30-42" which was usually enough, with the length of white adjusts, to do most of the time. Once in a while I'd add a webbing round loop to extend a leg but not often.
 
Tom Dunlap said:
I don't

a couple of clues from memory.

Two pieces of large [orange[ Tenex are used. One buried into the other to form the big eye. Then some Brummel-esque crossovers to lock all four legs in place and share the load.

I used it as a 2, 3, 4 leg spider. The orange legs were about 30-42" which was usually enough, with the length of white adjusts, to do most of the time. Once in a while I'd add a webbing round loop to extend a leg but not often.
Click to expand...
That’s interesting. I may just have to play with the idea, but my brain has been going down a different rabbit hole of a sling idea For a while now.
 
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