So here is a thought (may be stupid, may not, you tell me), I get the 3/4" shackle is way over kill, but assuming (yeah I know, an ass out of you and me) the mounting is equally as strong as the shackle then something else (winch rope?) would be the weak link. If the rope breaks and the shackle is retained by it's equally strong mounting point then it would seem to be less dangerous having just rope fly through the air as opposed to rope with a piece of metal (ie cheap or undersized shackle) flying through the air...... In other words, know your gear and know what is, or may be, the weak link?......
Synthetic rope failure: Does it drop or recoil?
- Thread starter jjvw
- Start date
I have a very similar discussion with my rescue lieutenants at work. They insist on having the drum as full as possible on the 15,000 pound Warn industrial winches we have on the front of our heavy rescue companies. Then, when it is all spooled on neat or otherwise, it is within a 1/2" of contacting all kinds of stationary stuff........
OP
What is a good length to have on the drum? 75 feet? I have to pull this apart again soon, so it's easy enough to cut some more off.
Good question, I know what I like but mrblaine will be the best one to answer this. For me it depends on the winch and the size of the drum and rope. At work we use 1/2" rope and there is somewhere around 100' on the winch, I recommended 60' so if we pull a side load we have much more room to play with. Typically we try and do things in a single pull due to the nature of our business.....on my own jeep I need to remove some, I am thinking about cutting it down to 70' or so from the 90+ it is now. I have an XD9000 with 3/8" masterpull XD Line.
The problem with these discussions is one can never intuit someone else's perceptions well enough to clarify all the points needed. The issue is not the overkill use of the shackle rated 5 times as high as it needs to be, the issue is demanding that winches should be used with something that has a 5-1 safety factor while fully ignoring that the winch has no safety factor. It is the mixing and matching of the rules that I take issue with. There is nothing wrong with using a 3/4" quality bow shackle as a connection point or in your rigging. It just isn't required and the only reason it ever started is because it says 4.75 Ton WLL on it which is 9500 lbs. or the equivalent of most winches rated capacity.
What happens is they look at the standard shackle with its 5-1 safety factor and then start trying to make every other piece of gear slot into that standard and that fucks everything up. Then they want overhead lifting weight ratings and safety factors on thimbles and even Crosby explains why thimbles are not rated. They are not considered a connection because they aren't.
I don't know the length. I like a bit of room under the full spool of line equal to at least two diameters of line if at all possible to give it room to stack up on one side if needed before you reset and move the stack over.
OP
Sounds like there would be some variation between models. I'll take a closer look when the time comes.
Point well taken, I see your point on mixing the rules and creating more BS and marketing as well as just overall confusion. I teach a good bit of rope rescue stuff for my fire dept. as well as the state and one of the things NFPA has instilled is a 15:1 safety factor, this, on the surface sounds a bit extreme until one starts to look at ignorance in action. A person who has a little knowledge sets up a rope rescue system but has no knowledge about critical angles and ends up pulling a steel ballard out of the ground, dropping a 200 lb. mannikin in the process (luckily it was a training event and not a live rescue). Point being know your equipment and get training in the use of the equipment you carry. But sometimes your equipment may need to be placed at less than optimal angles, extra strength is not a bad thing, but lack of knowing what you are truly doing is.....
Look at the reason this thread was started. The owner is clearly not an idiot and is in fact one of the more knowledgeable folks when it comes to taking care of business. He is pragmatic and pays attention to the details that matter. Even then, he still did not believe that his fairlead would be the ultimate point of failure. If someone that sharp ignores the obvious, how do we teach those who are far less receptive? I'm just thankful that his rig wasn't hanging off the side of a shelf road when the line parted.
OP
One reason I thought I liked this particular fairlead was because the radius was so large compared to the aluminum hawses I have seen. I was focusing on one specific detail and not paying attention to the others.
When the new fairlead arrives, I'll be studying each to see what the differences are. Both at the time of install and later on as I put some wear on the replacement.
OP
I forget the reason it came up, but that was when it was suggested I should not be using it.
I have the same recollection; I also have idea what the overall subject was, or what else was being discussed, but I know the nature of that fairlead surfaced...along with talking about the weight, and how people didn't even notice it on the front of the rig.
So, as I understand it, the real issue is not so much the steel vs. aluminum it is the surface texture. If one was to have some burning desire to have a steel hawse fairlead and spent a ridiculous amount of time smoothing it all out from the sand cast texture to something resembling a finely machined and polished surface then there would be no issue..... of course who has that kind of time to do such a thing.......
That's only about an hour's actual work for someone that has the tools to do it. Throw it in the mill and machine the radius to be approximately smooth and of the correct size, and then go at it with the polishing equipment. I saw the guys at the local machine shop build a similar widget awhile back, and that's about all there was to it... although I do recall a stint in a tumbler, but since that was unattended I'm not counting those hours. It's still retarded to do it unless you actually need such a piece, but it's possible.
One thing to be aware of is a straight line pull is going to have more strength than a side or angled pull.
OP
Side or angled pulls all depend on the degree of angle the rope is being forced to run through. In rope rescue we have a term, critical angle. This refers to the multiplying of forces caused by the angle, on an anchor system you want the angle higher, ie. 0° will share the load equally on a multi point anchor where an angle of 120° will multiply the load to 150% on each anchor. The opposite is true for change of direction anchors, if the rope is running straight through (or 180°) then there is no load on the anchor, but reduce that to 150° and the load is multiplied up to 4 times.... depending on the application. So as the rope on the winch runs through the fairlead if it is "bending" only a few degrees, the load is higher than if it was straight but not significantly. On the other hand, if the rope is "bending" 90° coming through the fairlead then the load will be many times higher than if it were straight. Measured at the bend is where the increase would be, obviously the load itself is the same weight, but some of the increase is carried through the bend to the winch as well, the rope (or cable or wire rope) is seeing that higher load right at the apex of the "bend".......
There isn't a good answer really. It depends on the situation, whether you can reset to unstack the wraps, what the normal pull lengths are, etc. If you can't reset and you need to do long enough pulls often enough that the stacking is a problem, then you are using the wrong winch. What are you using the winch for?
If one were inclined, that overlooks the rust issue. This is better.
https://www.devon4x4.com/Dana 44-stainless-fairlead-for-lowline-winch.html