spider legs

[treewhisperer1]

We've seen examples of spider legs in crane work, how about in normal rigging operations.
When do you use them?
What type of material and what size?
Should they be a certain size in relation to the rigging line they are being attached to?
How do you normally set them up?-pics!

I have been playing around with them a little and wanted to see what others are doing.

 

[Norm_Hall]

We've used them. The nice thing about a crane is the floating anchor (hook). Using them in rigging scenario's is a little different, but can be of value. Here is a sequence of pics where we used them on a weeping willow removal. The lowering line is a 3 strand 1/2" diameter NE Ropes Safety Blue. There is a locking ladder snap spliced on the end using a stainless steel teardrop thimble. The spider legs are 5/8" tenex.

 

[Norm_Hall]

View of the rigging system.

 

[treewhisperer1]

So Norm you dont attach the spider legs to the rigging line , by means of klemheist or prusssic knots?

 

[treewhisperer1]

I just saw your second pic and must say you system is really nice. Seems easier/faster to rig!

 

[Norm_Hall]

In this pic, the cutter is not leaving enough weight after the butt tie off. There should be close to the same weight after each tie off to balance/or keep the limb from tipping.

 

[Norm_Hall]

End result; the tip end dropped and the butt end raised up and into the bucket. You can also see the top of the GRCS mounted on the trunk near the base.

 

[Norm_Hall]

[ QUOTE ]
I just saw your second pic and must say you system is really nice. Seems easier/faster to rig!

[/ QUOTE ]

That's our knotless rigging system. The ladder snap is quik and locking, so nothing will come out of it. On removals, we use 3/8" spliced loops for hitching to the limb and then on the snap. We use this for lite rigging only (500 lbs. max). This system is sweet on conifers as we can choke up to 4 or 5 limbs in 1 set up.
We do use single spider legs anchored with a klemheist when the rigging calls for it.
I forgot to mention that we have 3/8" X 15', and longer, Validator 12 spider legs for hitching onto the 1/2" and 9/16" lowering lines. Size does matter.

 

[Colin]

I'm trying to cypher why it was done like that in the first place, and then to defeat the purpose by cutting it at the wrong place.
I woulda done it sans spider leg. KISS

 

[treebear]

Nice setup but it seemed a bit risky with the bucket into the risk zone of the setup. What if the rigging point failed. Part from that static loads are always better than dynamic.
Svein

 

[Jamin_Mayer]

I create "balancers" (I call'em balancers) when I forsee the need. But, ever since I got the GRCS I can lift/lower limbs without worrying about something below getting hit. Balancing is a good trick to have in the bag, but not always practical.

And like Butch pointed out: In that example it was a great intention, but poor execution. Those balancing situations are difficult to judge and take some effort to get good at them.

Again, the GRCS (I'm so glad I bought one)

eliminates 99% of the need to use a "balancer" because of the lift, then lower technique. At least, that is what I have discovered.

 

[Reg]

Norm

Looks and sounds a good system. I'm a also curious to know why it was used in this instance. Can't see what is underneath, so don't understand the need to take of and balance such a proportionately large section in its entirety. Please explain

 

[Norm_Hall]

It was a training moment. Nothing to worry about beneath. I asked if they wanted to try a new technique (to them) and explained how to set it up. They were up for a new option. In the process of taking pictures, I neglected to tell them where to cut it. My fault. The operator and the bucket were OK. I was fortunate to get pictures of it to show the rest of the Team what NOT to do. That was back in the winter of 2005. This crew has continued to use spider legs in the removal of all the diseased Amer. elms this past summer & fall. It's a great tool, but has limitations.

The rigging anchors are at least 8" diameter. There was absolutely no doubt about this rigging set up being able to hold the limb being removed. The top of the right side was stone dead, but was no more than 1 year ago. We have been doing winter work at this complex for over 10 years.

 

[RogerM]

[ QUOTE ]
Part from that static loads are always better than dynamic.
Svein

[/ QUOTE ]
For my own understanding...
If the cut was made at the proper place (closer to the trunk) and the spider legs "balanced" the load, and the lowering line was tensioned enough...wouldn't that load be
considered static? (forgive the run on sentence)

 

[Jamin_Mayer]

[ QUOTE ]
It was a training moment.

[/ QUOTE ]

Ahhh. That clarifys things.

 

[Norm_Hall]

[/ QUOTE ]If the cut was made at the proper place (closer to the trunk) and the spider legs "balanced" the load, and the lowering line was tensioned enough...wouldn't that load be
considered static?

[/ QUOTE ]

Absolutely!

 

[Zac]

We don't use spiderlegs all that often. When it works, it's awesome to have the added control and stability. Tie a klem to the rigging line and you're off...

 

[Stumper]

Balancers are just the right tool for removing a low limb over a fragile patio cover. Get a rope in the tips place a balancer near the butt (or vice- versa) cut part way and rotate thta stinker on th ehinga nd never ever touch that aluminium (paper mache?) bit of roofing.

 

[Colin]

Taglines go a long way, too. Even a polesaw.

 

[Colin]

[ QUOTE ]
I neglected to tell them where to cut it. My fault. The operator and the bucket were OK.

[/ QUOTE ]

Norm

Accidents occur in this industry all the time, we pay exuberant prices for insurance and when I see pictures like that I cringe knowing what will come. Norm, you are way above that and you cannot be there every minute of the day holding hands with incompetence and blaming yourself.

To help in selecting people for the job I often ask them to do an aptitude test. I wait while they complete it. There are many to choose from and search the net you will find them. Here is a link to a good one. I test their aptitudes not their IQ, there is a difference, you need people with a brain that can figure things out ... see trouble coming their way. Mechanical aptitude and spacial reasoning are key components to good tree work.

Recently I read that a ground worker was killed when lowering a branch cut from a bucket, again I assure you that he was in the swing zone or under the load, no escape path, no foresight. It's time for us to raise the bar and start using some logical process to select the right people over the ones who simply show or cop the conditions.

Run the test by some of your better guys and yourself, you'll soon see a pattern emerge. You need great people to build a greater business, like a resistograph and tomograph to the tree we need tests to see inside peoples heads.

http://www.psychometric-success.com/faq/faq-mechanical-reasoning-tests.htm

I apologies' for derailing the thread but do believe that it's important to cover this point.

Thank you for being brave enough to show that picture, and thank you for not being hostile toward me for speaking my mind. (fingers crossed)