Light fixture safety cables

Yoke have two bolts holding the body. My understanding is that that built in redundancy relieves us of body safeties.
Sorry, not buying that argument.
My EC Parellisphere has a non-forged eye-bolt just behind the top shutter, 'course it weighs about 30 lbs. It may have been the first theatrical fixture to have an attachment point. Film/TV fixtures (Mole-Richardson, Bardwell-McCallister, et al.) had them for years before that.
 
Bill:

This was extremely informative. Despite what I thought was good training in college, I’ve been doing a number of things wrong. Not as wrong as some of the rigging I’ve seen over the years, but enough.

Thanks for the link!
 
I'm sure @What Rigger? @egilson1 @Ted jones et al will correct me if I'm wrong, but I believe best practice when swaging is to leave a minimum length of wire rope, equal to the cable's diameter, sticking out of the swage upon completion of crimping. Another good reason for not making one's own cables.
When I worked for (major flying company) and was trained to make compressions, I was told "If there's enough tail sticking out that you bleed when you press your thumb down on it and twist, that's too much." And I was literally made to do this. I got really good, really fast.

My current employer documents that the tail shall equal the diameter of the wire rope being pressed.

"Opinions vary"-Dalton, Road House
 
I was always told that the ends should be just visible outside the crimp because you could see that the cable went all the way through the ferrule. This is for rigging slings and not necessarily the safety cables.
Regards
Geoff
 
The NicoPress guide says the tail should protrude by 2x the wire rope diameter. I agree that heat shrink would be preferable to gaff tape or vinyl tape to prevent handling injuries.
 
The NicoPress guide says the tail should protrude by 2x the wire rope diameter. I agree that heat shrink would be preferable to gaff tape or vinyl tape to prevent handling injuries.
Can you link that since the Nico instructions I linked above don't say that? Thanks.

There is an electrical tape - 3m 88 maybe - thick and really sticky and stretchy - that works ok. And some have coated with epoxy - pretty easy and efficient with the syringe systems.
 
Can you link that since the Nico instructions I linked above don't say that? Thanks.

There is an electrical tape - 3m 88 maybe - thick and really sticky and stretchy - that works ok. And some have coated with epoxy - pretty easy and efficient with the syringe systems.

IIRC I have the printed document at the office, I'll look for it tomorrow.
 
I have seen ona gig where a motor chain fall out of a bag while it was being raised .

The motor was hung invert 100ft up with gac in a basket configuration. When the chain was being raised approximately 80ft up in the air the chain fell out of the bag. ( wrong size chainbag ).

What is the shockload?

This isn't a simple calculation. As the whole pile of chain is falling, its getting lighter and lighter, as link by link is stopped by. The free falling mass is continuously changing. So if you've got 80 feet of chain that gets dumped and starts to fall, in one second its only 48 feet of chain falling. Your GAC basket is taking more load the whole time the chain is in free fall, not just when it "hits" the bottom
 
IIRC I have the printed document at the office, I'll look for it tomorrow.
Of course now that I'm looking for it, I can't find it. In the mean time I'll defer to the PDF that was posted.
 
Also remember that the “shock load” equation is for an object in free fall. A chain running out of a bag is not in free fall, but rather at a changing velocity as the load changes, and as the length changes.
 
Just to show how training can vary;
I was taught 2 sleeves, the 2nd to contain the stabby ends.
:legalstuff:
As was I. Is there any issue with this way?
That is you have the 'first' (at thimble/loop) crimp for function and another farther down (away so you can see that the cable went all the way through and so there's no deformity) crimped afterwards right at the end so it doesn't stab anyone.
 
I have heard two sleeves weakens they eye but could be folk lore. Of course two are usually required for a splice.
 

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