Shackles???

banjo

banjo

Location
rhode island
Why are shackles on saddles legal? It seems to me that the same logic which outlaws screw gate biners would also apply to shackles. I'm really curious to know how the safe-makers rationalize this.
 
THE SHACKLEs on the Treeflex have a nylon sleeve on the threads to lock the pin from unscrewing. The shackles were developed for yachting and yacht racing. The shackles have proven themselves in those conditions where the rigging is snapped and popped a heck of a lot more than on a tree climber's harness.

Nothing is fool proof of course. If a person doesn't follow the instructions for using anything that they buy whether it's a toaster or life support there is a chance that they could die.

I'm not familiar with the shackles on the new Komet harness. The instructions for the BFII say that a thread locking compound needs to be used. YOu would be surprised how many things in common use are locked together using thread lockers. Many parts of your car engine have them to keep things from flying apart. If you're not confident in the thread lockers you should go to the Lock Tite homepage to see the applications.
 
I think he's saying you can slip a thimble through there, then tie (splice) the bridge straight to the thimbles/harness. Take the shackle out of the equation.

Someone had some pics of that setup up here a while ago.

love
nick
 
Yachts have redundancies built into their systems. If one of these shackles was to fail, all would not be lost. Of course there is always potential for injury but if you lose the main sail you have options. If you lose the bridge on a saddle you don't have options. The issue of using threadlockers seems like a band-aid approach that doesn't address the inherent dangers of using these shackles in primary life support systems. I spoke to technical support at Henkel(the company who makes loctite) and they would not provide any guarantee that loctite is acceptable in this application.
Another question: Where can I find the results from the independent testing of the shackles in tree care applications. They are on the BF2 so Komet must have tested them in this application. Right? Same goes for Treeflex.
Does somebody actually have to fall out of a tree for this to be taken seriously.

(edited for spelling)
 
This may seem like I'm becoming the defender of Safety Technology and Komet. That isn't the case.

Of course Henkel isn't going to give any sort of guarantee about the applicability of threadlockers. That would be a huge liability issue.

This story has been told before, it emphasizes my confidence in LT technology.

The bearing that supported the drum on my chuck and duck chipper spun on it's shaft. A friend of mine who is a millwright helped me fix the machine. We pulled the bearing off and found that there was about 3/32" of shaft that hadn't been damaged. We had a 'center' for the new bearing. After cleaning up the shaft, test fitting, using primer and then 'gluing' the new bearing in place the machine was put back in service. The chipper didn't miss a beat. It ate up logs and brush as well with the 'bandaid'. I used the chipper for several months before selling it. I never heard from the guy who bought it from me. I would guess that I might have if it would have failed.

My millwright buddy said that many of the LT products are found in the toolboxes of mechanics/millwrights and are accepted and proven when used according to directions.

Using solid rings may make harnesses more 'fool' proof. But, what do the manufacturers/trade guidelines say about inspections?

I've been using screw links/maillon rapides and shackles for many years. If the application warrants anything more than finger tightening I do that. In a harness application either threadlocker or a bit of wrench tightening is warranted. so far the only loosening that I've ever found was on a hand tightened screwlink that loosened about 1/6 of a turn from finger tight. Before that setup would have been compromised it would have taken about 6-8 full turns.

Inspecting gear every time it's used is prudent, and required. Daily inspection of a harness isn't enough, every time mine slides onto my waist it gets an inspection.
 
Banjo, Tom is right: rated shackles are definitely safe, that is why they are ubiquitous in rigging across a wide range of industries.

As for the security of the threads holding them together, seeing is believing. Get a shackle and assemble it with thread-locking compound. After it cures for the suggested time, remove the pin and note the effort it takes. I think you'll find it very reassuring!

(Tom, you can add machinists to the list of those who have Loctite products in their toolbox!)
 
Shackles, unlike krabs(which are more akin to a well moused open hook); are a real 2 leg support device, thus need less diameter/size for the same krab strength. There are many industrial uses as noted, that wouldn't okay a krab's weaknesses. Partially becasue of 2 legs stabilizing the system's strength where a krab wouldn't. If the leg of a krab gets leveraged, weak etc.; it has no other support. A shackles lenght is the same strength inline, but altering the width alters strength inline.

Locktite does present some frictions/ not lubrications. It is advisable i believe to tighten higher than recommeded to seat properly(because some of the input force is going to fight the locktite frictions, not the seating).
 
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