Great wire rope trick

[Botabill]

The facts have been stated. Doubt is optional. I dont know why you expect others to tell you the facts and, as has been done, give pertinent brief explanation, and then be responsible for dispelling doubt of unstated nature. You need to satisfy your doubt by consulting reference materials. Try a key word search in Google.
larry

First Spiderlk I should say that just because my post appeared below yours doesn't mean I was referring to you in my post. I wasn't. Actually your comments throughout this series made more sense than some other opinions expressed. Knowing that may or may not influence you to rethink your comments directed at me. Second... I did the research and have the answer (I'm just that obsessed with fact) but I'm not sure anyone who has expressed an opposite view here would be interested.

I don't expect others to tell me the facts. I appreciate it when they do. But
honestly it does irk me when I see people who have no clue beat up on folks who offer us something out of good will.

I must be getting old. I have little patience with opinions. They're like belly buttons. Everyone has one but I really am not interested in anyones belly button. I appreciate the the offerings made by folks like BX24 and factual submissions by folks who back up their statements with sources that can be verified.

 

[bx24]

Well, I started off with good intentions and I was going to let sleeping dogs lie, but after watching a re-run of Mythbusters, I was curious of something. (The episode showed them banging two hammer (claw type) heads together to see if they could get them to "chip" ..... They were not able to get them to chip)

For those of you who have actually used this technique with wire rope and a tail, has it ever failed you? I am asking this not because I am trying to make a point, but rather I am curious if you have had the same "luck" that I have had. Just because you do something and nothing bad happens does not make the activity safe (I understand this). But is this a situation similar to banging hammers together or using cell phones while you are pumping gas where it was commonly known to be a bad idea, but the Mythbusters guys could not prove the theory? Or have those of you who have done this experienced failures first hand? I really am curious if my ten years of experience using this technique (before I was eduacated about the pitfalls here) was I simply lucky? I welcome all responses but I know what the text books say. I am really looking for folks who have had real world experience.

Again, using ropes of any kind under tension can be extremely dangerous so please research and take appropriate precautions for your situation!

I don't feel real bad about making this thread longer since it helps TractorByNet to sell more ads because of increased posts!

 

[sandman2234]

Having a wire rope cable fail on you or having the beforementioned spliced loops fail, would depend on just what it is your doing with it. If your pulling on a stuck skidder with a D-7 or D-9 Dozer and using 1" wire rope, then there is a good chance it is going to fail, if the skidder is really stuck and the dozer is able to get traction. If your pulling a tree limb out of the back yard with a JD 790 and you are using the same cable, I would expect the splice to hold.
What you use it for is entirely up to each of you. Use your best judgement as to what you are doing and what it should take for the splice or the cable to stay together during the task you are putting it through.
I stand by my statement, after having tested more 5' samples of rope wire (to failure) than most of you have handled in your lifetimes, except maybe for a few select persons, that the spliced loops will fail prior to the rope reaching 100 % of its capacity. For most of us, that is way more than we will ever put it thru, but as shown, it will not be able to handle the entire strength of the cable.
If it looks good enough for you, and you have had excellant results with it, great! I would probably use it also, as long as I wasn't pulling something serious with it. I think the O/P was trying to help with something that most people aren't familar with, and should be commended for his posting. As with anything on the 'net, take it with a grain of salt, do your homework, and try to be as safe as you can.
Just for an example, the one inch cable I mention probably has a breaking load of in excess of 100,000 pounds, although it's rating is considerably less than that. Snap a piece of that in a dead pull and you will have quite an mess to clean up, especially in your shorts.
David from jax

 

[barneyrb]

3/8 cable, Konig PTO winch, sticky Louisiana gumbo, 3000# CJ5, 5000# Dodge Ramcharger, Blazer, Bronco, ya get the picture. We NEVER had one fail due to lack of strength. We have had ROTTEN cable fail and when it gets to that stage the only fix is new cable. When I installed new cable I always used this method to put the hook (with about a foot of heavy chain) on. The only difference between your methods and mine is I would take galvinized heavy elecrtic fence wire and wrap the tail (and cable together). Wrapped the tail and cable the way you would wrap a guide on a fishing rod (to keep raw ends from gouging hands). Pulled bunches of trucks out and never had a clamp on the cable. Thank god for 4 wheelers and Rangers every hunting season. I knew I couldn't keep my mouth shut on this one.

 

[cityfarma]

I did not realise that disagreeing with a post would bring out so much discussion. I have read all opinions and therefore am prepared to agree with some points but have not changed my original postulation. As demonstrated with a 3 strand cable, I maintain that the strength is less than 100% but not as low as I had originally thought. With 3 strands the weakest point is the single strand side at the main cable but (as I now have had pointed out) the pull is 1/2 of the total pull or about 2/3 of breaking strain. In cables with more strands such as 4/5 the strength is closer to 100% as the split is closer to 1:1 each side. In this I have assumed a long splice so friction is high and the splice does not slip.

I also agree with Sandman that very few cables are used anywhere near their breaking strain therefore few will break even if the splice is less than 100%.

Cityfarma

 

[bx24]

I did not realise that disagreeing with a post would bring out so much discussion. I have read all opinions and therefore am prepared to agree with some points but have not changed my original postulation. As demonstrated with a 3 strand cable, I maintain that the strength is less than 100% but not as low as I had originally thought. With 3 strands the weakest point is the single strand side at the main cable but (as I now have had pointed out) the pull is 1/2 of the total pull or about 2/3 of breaking strain. In cables with more strands such as 4/5 the strength is closer to 100% as the split is closer to 1:1 each side. In this I have assumed a long splice so friction is high and the splice does not slip.

I also agree with Sandman that very few cables are used anywhere near their breaking strain therefore few will break even if the splice is less than 100%.

Cityfarma

OK, so unless I am reading these wrong so far, this method has never failed anyone ..... Right?

Cityfarma- I cannot argue with your logic other than to say the raw straight cable ALWAYS failed before the eye.

Again, it is very stupid to say "it will never happen" but so far, no one has ever witnessed one fail.

One of the other pieces of equipment we ran was a $200K "fish tape" with a 20,000 pull capacity. We would argue with the engineers who built it all the time about one thing or another. While we wrong on many occasions with our assumptions because of something we did not take into account, we ended up stumping the pros more often than not because while they built it and tested it a couple of times, we used it almost more than 2000 hours per year (we were OT sluts) and we knew how it performed in reality vs. how it was designed to perform.

Again, I welcome all input and to be safe is to stay alive, but I am waiting to hear from someone that this failed them.

 

[SPYDERLK]

I stand by my statement, after having tested more 5' samples of rope wire (to failure) than most of you have handled in your lifetimes, except maybe for a few select persons, that the spliced loops will fail prior to the rope reaching 100 % of its capacity. For most of us, that is way more than we will ever put it thru, but as shown, it will not be able to handle the entire strength of the cable.

5' may be an accepted length for testing some splices on some cable sizes. I would never test this splice on a 5' sample on anything larger than 1/4' cable. The reason is that this type of splice has to bed in such that strands share the load without intense loading of isolated strands. Some small amount of interstrand slip must happen while this bedding in occurs. If the cable is short relative to its diameter then there is not enuf length in the strands so that they can stretch elastically by an amount sufficient to ease the imperfections inherent in the 'green' splice. The cable sample should be many multiples of its diameter and the pull end must be captured/consolidated well. The splice should be loaded cyclicly several times at increasing levels in order to realize the full strength. The splice will be stronger than the parent cable if the tail is tied in well and the loop is allowed to season briefly in light to medium duty use. It will be stronger because there are 2X the strands carrying the load in the loop.
larry

 

[sandman2234]

Correctly preformed wire rope should already be "bedded", but I understand your reasoning. However, for Modulus of Elasticity measurements, you can't load and unload the sample without messing with the final results. A piece of 5' cable will probably stretch about a foot before reaching maximum load and failing. A properly designed test machine should have the proper grips to hold the cable without pinching, or allowing the cable to load in an unbalanced method. However, these are lab tests, and the O/P was suggesting anything but that.
David from jax

 

[SPYDERLK]

Correctly preformed wire rope should already be "bedded", but I understand your reasoning. However, for Modulus of Elasticity measurements, you can't load and unload the sample without messing with the final results. A piece of 5' cable will probably stretch about a foot before reaching maximum load and failing. A properly designed test machine should have the proper grips to hold the cable without pinching, or allowing the cable to load in an unbalanced method. However, these are lab tests, and the O/P was suggesting anything but that.
David from jax

I understand yours too, but lets work with that a minute. I would say your modulus will be higher with a cyclicly seasoned cable because the load will be more evenly shared. Yes, some cable strands will be unavoidable strained during bed in but the plastic stretch this entails will be small to non existent if the sample has real world length. This much more ideal [and real] situation would have little corrupting influence on the modulus measurement.

I know that cables stretch a bit as they tighten on themselves during loading, but Im guessing that 20% is stretching it a bit. Id go for 5% in the line and the apparency of more in the loop because it flattens.

Yes, the original post did not suggest lab tests. That use was real world - real world length, repeated use/cycling, flexing of the relaxed cable. Not well controlled, but a situation that is serendipitously better suited, for this splice, to converting a sows ear to a silk purse. The lab test may start with a better done splice, but as I see your description, it immediately abuses it to destruction by making lab choices that allow testing to be expedited.

I guess my point is that when you do them right and treat them well during their formative years, each leg of the loop will support close to the breaking strength of the parent cable. That gives a large safety margin.
larry

 

[exiled]

Paul. Us hands know what you was saying. Brother there will always be a "Right" way to do things. Look at 75% of osha regalations. You have a good bit of over kill, then you have rules that really should never be said. But there will always be that chance that something will fail.
To my horror yesterday on my home I came up on 2 young guys 1 was still in late teens the other in his early 20's. ! had gotten his 4wheeler barried in mud. The teenager was at the back of the 4wheeler right beside the cable ran to a winch mounted on the front bumber of a pickup and the other guy was working the winch. I stopped and asked the young man to move out of the way. He quickly told me how many times he has done this. I guess when I asked him what he was going to do when whatever he had that cable hooked off to broke a bad picture displayed in his mind cause he quickly got out of the way. This afternoon the guys pullled in my driveway and thanked me. They had never thought about something the cable tied to breaking off and destroying everthing in its recoiling path.
What is my point? Real simple. The best laid ropes, cables, and chains come apart. A run is only as strong as it's weakest link. You do not get in the load path for any reason, so the danger is taken out of the picture. Sometimes you just have to do what you got to do to get it done.