# Improperly swaged wirerope/ aircraft cables



## Dagger (Aug 23, 2019)

For example 1/8" wire rope with 1 sleeve and 1 crimp

Or cables crimped " sideways"

I refused to use them when it was provided.

Was I too overcautious??

Does anybody have an opinion ? Could it may have been used.? The object to be hanged -It was like well within breaking strength ( weight was ~ 300lbs. )

My main concern was the improper crimping.

Using thimbles or no make a difference??


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## egilson1 (Aug 23, 2019)

I have a strong opinion on this. Your refusal to use it was correct. A single compression on a swage fitting is not going to hold even the working load limit based on a 5:1 design factor on breaking strength. This is assuming the tool you are using requires multiple compressions per fitting. It’s all about surface area and the coefficient of friction. Simply stated if it’s anything but what the manufacturer of the tool requires for number of compressions don’t use it.


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## Dagger (Aug 23, 2019)

Crimped " sideways" as in the image (2nd image)
Effect on the cable?
I see lighting safetys crimped that way. Why?


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## gafftapegreenia (Aug 23, 2019)

Dagger said:


> Crimped " sideways" as in the image (2nd image)
> Effect on the cable?
> I see lighting safetys crimped that way. Why?



A "crimp" done that way is WRONG. It is dangerous garbage and should be immediately destroyed. It is NOT appropriate for any use!

Why do cables get made that way? Because the person making them has NO IDEA what they are doing.


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## danTt (Aug 23, 2019)

I'm equally concerned with you hanging 300lbs on an 1/8" cable, unless I misunderstand your post.


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## egilson1 (Aug 23, 2019)

danTt said:


> I'm equally concerned with you hanging 300lbs on an 1/8" cable, unless I misunderstand your post.




300lbs is fine on 1/8” if it’s a static sling and not running rigging. 2000lbs MBs with a 5:1 DF for a working load limit of 400lbs.


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## josh88 (Aug 23, 2019)

danTt said:


> I'm equally concerned with you hanging 300lbs on an 1/8" cable, unless I misunderstand your post.


Well 1/8" has a breaking strength of 2,000 pounds so a 5:1 factor is 400 which, or 200 for a 10:1. Seems within the range of acceptable for some uses.


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## Dagger (Aug 24, 2019)

egilson1 said:


> 300lbs is fine on 1/8” if it’s a static sling and not running rigging. 2000lbs MBs with a 5:1 DF for a working load limit of 400lbs.




josh88 said:


> Well 1/8" has a breaking strength of 2,000 pounds so a 5:1 factor is 400 which, or 200 for a 10:1. Seems within the range of acceptable for some uses.



Does making a loop swage decreases the breaking strngth if 2000lbs? 

And the jumber of crimps also are factor? And using thimbles in the loop necessary?


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## BillConnerFASTC (Aug 24, 2019)

egilson1 said:


> a static sling and not running rigging.



Rather than suggest my interpretation could you clarify this statement?


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## egilson1 (Aug 24, 2019)

BillConnerFASTC said:


> Rather than suggest my interpretation could you clarify this statement?



Absolutely. It was late for me when I posted so I probably didn’t phrase that as well as I could have. 

By static sling I mean a wire rope assembly that is not being lengthened or shortened by being wrapped on a drum, OR is not being moved over a sheave.


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## RonHebbard (Aug 24, 2019)

egilson1 said:


> Absolutely. It was late for me when I posted so I probably didn’t phrase that as well as I could have.
> 
> By static sling I mean a wire rope assembly that is not being lengthened or shortened by being wrapped on a drum, OR is not being moved over a sheave.


* @egilson1* While we're chit-chatting; what're your thoughts if / when comparing the effects of winding aircraft cable onto spiral-cut drums versus yo-yo drums from the perspective of cable wear / cable damage / life expectancy aside from yo-yo drums inherent self-varying rates of travel which are often useful in automated vertical lift and land applications. 
Toodleoo! 
Ron Hebbard


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## BillConnerFASTC (Aug 24, 2019)

egilson1 said:


> Absolutely. It was late for me when I posted so I probably didn’t phrase that as well as I could have.
> 
> By static sling I mean a wire rope assembly that is not being lengthened or shortened by being wrapped on a drum, OR is not being moved over a sheave.


So you would accept the 5:1 if it were attached to a counterweight batten for instance? My criteria is impact load, so a load attached to a batten that will fly requires an 8:1 design factor.


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## josh88 (Aug 24, 2019)

BillConnerFASTC said:


> So you would accept the 5:1 if it were attached to a counterweight batten for instance? My criteria is impact load, so a load attached to a batten that will fly requires an 8:1 design factor.


I would think Ethan's stipulation of not being run over a sheave would include a headblock and then for that matter the loft blocks holding the batten. Those lines would want a higher design factor.

But I believe you're saying using wire rope statically to "dead hang" something from a batten. In which case because it stays hung the way it is and isn't the bit that is moving, it would be acceptable.


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## BillConnerFASTC (Aug 24, 2019)

Still subject to impact load, even if it doesn't bend while going up and down. Just like a trim chain - 8:1. It's in the load path of a moving object. While manual impact load may be only 1.25 or so, motorized can be much more. I've seen bent head block beams - that was 400 fpm and around 3.5. to suggest the load could be hung from that at 5:1 seems to close


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## Dagger (Aug 25, 2019)

Any difference in using wire rope clips or using crimped sleeves?

What it is static but the wire rope gets wrapped around once ( or more ) around an object ( like pipes) ?


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## BillConnerFASTC (Aug 25, 2019)

Yes. Besides the obvious properly installed swaged fittings are as strong as the wire rope. Clips automatically rexuces thestrength to 80 percent. Also from my experience is easier to properly use swages than clips. Just not easy to actually torque the nuts on a clip, but it can be done. Also easier to check a swage witha a go no go guage. Torque wrench is not as easy.

If you have not done this, do not do it for the first time without a trained rigger to oversee and check your work. If youhave not done it, you don't know what you dont know.

I dont see many reasons to wrap the wire rope around a pipe. First, to remove or change you have to cut it. Almost all connections are made between a thimble and a clip, clamp, chain, or other device.

If overheads, this is not work to do your first time without eyes on supervision.


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## RonHebbard (Aug 25, 2019)

egilson1 said:


> Absolutely. It was late for me when I posted so I probably didn’t phrase that as well as I could have.
> 
> By static sling I mean a wire rope assembly that is not being lengthened or shortened by being wrapped on a drum, OR is not being moved over a sheave.


 *@egilson1 * and/ or *@What Rigger?* 
While we're veering along; if / when you pass a single length of aircraft cable over the ~1.875" O.D. of one horizontal length of 1.5" I.D. schedule 40 iron / steel (or aluminum for that matter) pipe and properly anchor BOTH ends of this single run of cable to two rated attachment points on one, common, load; does this qualify as two supporting runs of cable and double the cable's capacity or would this be incorrect since the cable is not secured to the supporting pipe and support would be totally lost were the single run of cable to break, or either of its two terminations fail*??* 
Toodleoo! 
Ron Hebbard


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## BillConnerFASTC (Aug 25, 2019)

Like a trim chain, it is a double load path and does split the load between both legs.


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## RonHebbard (Aug 25, 2019)

BillConnerFASTC said:


> Like a trim chain, it is a double load path and does split the load between both legs.


The first trim chains I met were lengths of welded link chain with a rated snap hook on only one end which was intended to snap back into the chain. 
The next trim chains I met were lengths of welded link chain with a rated snap hook on one end and a ~2" diameter welded steel ring on the other. In this theatre they passed their trim chains over their system pipes and passed the end with the rated snap hook through the approximately 2" diameter welded steel ring choking the trim chain on the system pipe with the rated hook dangling down for attachment to their load. 
Sometimes they'd wrap the trim chain around a system pipe twice prior to choking it to effectively shorten its length. 
Sometimes they'd pass the rated snap hook through a crimped or swaged loop in an aircraft cable attached to a load and clip it back into itself as a method of varying the trim chain's length by, effectively, half link increments. 
*@egilson1* and *@What Rigger?* Comments*? *Thoughts*??* Peals of laughter*???* Screams of horror / terror*???? *
Toodleoo! 
Ron Hebbard


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## BillConnerFASTC (Aug 25, 2019)

Typically today it's a 30" or so length of grade 30 or for those that agree with the chain manufactures, like I do "Grade 63 hardened alloy chain meeting OSHA requirements for sling usage OSHA 1910.184(e)(5)" with one end captive on the thimble at end of lift line and other end anchored to the thimble with a shackle. Double load path.


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## RonHebbard (Aug 25, 2019)

BillConnerFASTC said:


> Typically today it's a 30" or so length of grade 30 or for those that agree with the chain manufactures, like I do "Grade 63 hardened alloy chain meeting OSHA requirements for sling usage OSHA 1910.184(e)(5)" with one end captive on the thimble at end of lift line and other end anchored to the thimble with a shackle. Double load path.


*Appreciated and understood in the case of finessing and securing system pipes to their supporting cables. * 
In the two theatres I spoke of previously, their trim chains were supplied and stored loose and used for attaching loads other than soft goods to system pipes. 
Toodleoo! 
Ron Hebbard


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## BillConnerFASTC (Aug 25, 2019)

From the ANSI standard for rigging:

2.63 Trim chain: A system employing a length of chain and fittings used to connect a lift line to a batten (or other load) and adjust its level relative to the other lift lines along the batten.


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## josh88 (Aug 26, 2019)

RonHebbard said:


> The first trim chains I met were lengths of welded link chain with a rated snap hook on only one end which was intended to snap back into the chain.


We had Tiffin Scenic in and redid a bunch of our rigging this summer, they (including one of their inspectors) were still fine with the rated snap hooks on trim chains and a safety bolt connecting the two legs of the chains. Wenger's engineers however didn't like them and replaced the snap hook with another shackle into the thimble (which matches the other end of the chain), and removed the safety bolt entirely. It was an interesting conversation.


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## gafftapegreenia (Aug 26, 2019)

josh88 said:


> We had Tiffin Scenic in and redid a bunch of our rigging this summer, they (including one of their inspectors) were still fine with the rated snap hooks on trim chains and a safety bolt connecting the two legs of the chains. Wenger's engineers however didn't like them and replaced the snap hook with another shackle into the thimble (which matches the other end of the chain), and removed the safety bolt entirely. It was an interesting conversation.



I don't think I've seen a "rated snap hook". Got a link?


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## BillConnerFASTC (Aug 26, 2019)

The safety bolts add no safety and can only cause problems.

Rated snap hooks are available but I find ones rated equal to the chain are large and expensive. 

But the debate will continue with strong opinions both ways. Like grade 30 or 63 - depends if you want to comply with OSHS.


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## josh88 (Aug 26, 2019)

gafftapegreenia said:


> I don't think I've seen a "rated snap hook". Got a link?


I dont, ours are 20 years old and I believe are brass, but are stamped with a rating. 


BillConnerFASTC said:


> The safety bolts add no safety and can only cause problems.
> Rated snap hooks are available but I find ones rated equal to the chain are large and expensive.
> But the debate will continue with strong opinions both ways. Like grade 30 or 63 - depends if you want to comply with OSHS.



Tiffin still specs the snap hooks and bolts in current installs apparently. Wenger's stance is that they don't spec the safety bolts anymore because its not worth it but feel there is still a minimal benefit as long as they are rated bolts. It was interesting because we had them in a week apart and the Wenger installer was surprised to see them and they wanted them changed before we hung any of their pieces from them. But then also just shackled up to the thimble on both sides which negated any leveling or trimming we had done and raised everything by 3-5 chain links.


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## Tom Strong (Aug 28, 2019)

Dagger said:


> For example 1/8" wire rope with 1 sleeve and 1 crimp



Several years ago I took a rigging class that involved making up some small slings and then taking them to a machine to have them broken. Most of the ones made correctly seemed to break around +/- 10% or so of the rated breaking strength, but I was curious what would happen if one wasn't done correctly. Going by memory, a single crimp on a single sleeve came in around 60-70% of the rated breaking strength of the cable, and it failed by slipping out of the sleeve. This was a very non-scientific test (we didn't repeat it, and I didn't even think to write down the results at the time) but it seems like the majority of the strength comes from the first crimp. It's not enough to be safe, and obviously you should never use it that way, but I'd be interested in seeing some real numbers on what happens when you don't terminate cables correctly. I would guess that the percentage of the strength you'd get from a single crimp would decrease as the cable gets larger too. 

Does anyone have access to a more scientific study of it?


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