phillyd2
Senior Member
What are they rated for?
Is "Hitch Shackle" a good idea? Also, recommendation for a tow strap.
- Thread starter jicko
- Start date
What are they rated for?
1engineer
Moderator
I know you are not and I did not mean anything derogatory or anything. What I meant is there is a lot of misinformation in this thread, not that you were spreading it lol. I was writing a big long complicated post but I virtually crumpled it up because unless people have the math then they wouldn't understand it so I took your advice. Now it's just long and not so complicated. Here is my overall response:
Vehicle Recoveries
From personal experience no recovery is the same. I'm sure you could ask [MENTION=118321]Jetboy[/MENTION] or [MENTION=66300]Intruder[/MENTION] or [MENTION=78273]Jeremy556[/MENTION] they would say it too. In some cases a gentle tug straight forward is all you need. In some cases you are pulling a guy up a 45 degree slope sideways while wedged on a rock. Those are two extremes but each could happen on the same day on the same trail. Ideally you would have specific equipment for every type of recovery but unfortunately most do not pull a trailer laden with block and tackles, different ropes and sheaves or even a variable winch. They have "X" equipment and that's it. Ingenuity is now required. I just wanted to give this background so everyone agrees that no two recoveries are the same.
Now, did anyone read my previous post? Really the most important thing about it was this: All things being equal (gvw, speed, etc) the method of recovery can cause a variance of force from 2K to 200K lbf! That is a big difference! No wonder things break! I don't care what you have in the back of the truck you don't have anything that can handle 200,000 lbf even for an instant. Yet you can generate that with a 5K vehicle going several mph and using a chain for recovery.
Now let's talk about specific things:
Shackle Pin tightness: Finger tight or cranked down?
It really does not matter AS LONG AS YOU HAVE FULL THREAD ENGAGEMENT! Why? Because depending on how you are rigged, a pin can get loose or tight in one pull. That's why, as a conscientious person, should always check your pin after each use. Failure to do so could result in failure of the pin. I have witnessed tight pins become loose and loose pins become tight. You just need to check them all the time. The big thing about the pins is thread shear. More on that later.
Shackle Orientation: Vertical or Horizontal?
In a perfect world both orientations would be used depending on the pull. In the real world either one is OK because they both have advantages and disadvantages, depending on the recovery. Example: My 4Runner is over a 20 foot 45 degree embankment. Your shackle is vertical and mine is horizontal. You are on flat ground and back just so the back bumper is over the edge. We hook the tow strap up. I am fine because my horizontal shackle swivels right up to 45 degrees. Your vertical shackle can go right to left but in this case we have to pull at a 45 degree angle. Yes, this will de-rate the working load somewhat but why? Because now instead of just having my threaded pin in double shear (very strong) I now could be just relying on the bending strength of the shackle and the shear strength of the pin threads. You are also pulling on the "weak" sides of the shackle.
Bent Pin?
Some here believe hooking up to just a pin in the hitch is OK. Some here believe that that is a terrible idea. The truth is in the middle of course. If I have to just make short easy pull to get someone off the ice then the pin is fine. If I go back to my example of pulling a guy up a 45 degree hill through rocks then I can almost guarantee you will have a bent pin and those things are hard to cut out.
Bottom Line:
Every recovery is different. Some will require a LOT of force and some will require no more than a few guys pushing on the bumper. We only have a fixed amount of equipment to make recoveries so that means you have to be smart and ingenious when using that equipment.
Many here are against using wire rope on a winch or using chain or cable to pull with. I am not in certain applications because certain applications require it. You don't see a wrecker using synthetic rope for a reason. The challenge with using cable or chain is there is no room for error. If there is an error then something or somebody could get hurt much easier than with a recovery strap for example. They all have their place and at the end of the day you end up using what you have. Every method has it's place and application. Don't ever expect to have a "one size fits all" mentality when you are putting together your recovery kit. Use what you are comfortable with knowing that you can get over your head quickly if you don't know what you are doing. If I were you guys I would listen to [MENTION=66300]Intruder[/MENTION] and [MENTION=78273]Jeremy556[/MENTION]. They are two of the more experienced guys still posting here.
Edit: [MENTION=99702]jrandom[/MENTION] I did not even answer your question! In one pull you could go from having your full working load to having only 1/2 you working load based on the position of the rope in the shackle. Make sure you never buy a component based using it at or near its limits. If you are pulling 4K lbs don't buy a 5K strap, buy a 10K strap. Same for everything else. Hope this helps.
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Jeremy556
New member
TBrock
New member
1engineer
Moderator
The key is sizing your components correctly. A swivel hoist ring is fine. A shackle is fine. The recovery rings on the truck are fine. Shoot, a rope is fine as long as it is sized correctly!
BobsTrail
Senior Member
It looks like a sling for a crane, here is a photo of mine with the two labels on it.
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wfo9
New member
I totally agreed with everything you said up to "I can almost guarantee you will have a bent pin".
I still don't see the bent pin being possible with the right equipment. The pin I have (which cost me all of $6 - the masterlock one mentioned earlier...) is 16mm stainless steel. And the strap I use on it (and what most people use) is either 2" or 2.5" at the connection point. The hitch itself will fail before this pin will bend. I'm confident of that just using common sense. This also aligns with the ARB snatch strap instruction video posted earlier (I think they know a bit about recovery)
I'll agree that it might not be the best choice in all circumstances (nothing ever is).., but I think it is the safest way to go in most common pulls and I'm sticking with it for those scenarios.
There is one thing you missed in your analysis. Unnecessary hardware adds to the potential for failure. Less parts = less failure, you should know that being an engineer. LOL
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1engineer
Moderator
Problem is everyone uses whatever they or someone else has in a situation. You happen to have a nice strap. People use looped wire rope, synthetic line, tow straps and chains. What happens if your recovery strap can't be used because of the situation? I agree: If you have matched equipment and If you have enough room for the pull and If it is not buried to China and If you are stuck in the right position then yes, you probably won't bend anything. Maybe it's just me but most recoveries I have been part of rarely line up with everything in perfect position.
And yes, the simpler the better. I don't have a winch. I have a heavy come along and a few sheave blocks and straps and ropes.
Curly Jefferson
New member
I find it hard to believe that you don't believe a stainless steel pin can bend when using a strap as you describe. I have a fair amount of B&W adjustable height hitches which use two (2) 5/8" stainless pins for height adjustment. We have had to replace these stainless steel pins on numerous occasions because they have bent. Its not easy getting them out after being bent either.
Tow & Stow? - Receiver Hitch | B & W Trailer Hitches
If I can find any of the bent pins, I'll post a picture.
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wfo9
New member
You are comparing apples and oranges now. I'm saying it won't bend in my application. Sure pins can bend with the right lever.... I'll bet those bent pin situations you speak of would have done some damage to our wimpy little hitches also. What diameter are the pins, what is the application?
A strap across the entire surface won't do it. These are as thick as most shackle clevis pins/bolts and the linkage is actually way stronger. The logic just does not make any sense to me. You will have a hard time convincing me.
Anything will break with enough force... I'm just not buying that these pins bend so easy and that a shackle will hold together under that same force. I would way rather have a pin bending than a shackle flying.
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Curly Jefferson
New member
They may not bend easy but most people who are trying to pull out a stuck vehicle with a strap are usually getting a running start at it. I'm not saying that's what I would do but I've seen a lot of people who were stuck and they probably wouldn't have gotten stuck if they were a bit smarter.
It would be interesting to do a few tests using a strap and a regular pin vs a stainless pin through the receiver hitch. I would think the stainless pin would bend easier.
If you want to read about this to understand it a bit better try this link:
https://www.extension.purdue.edu/extmedia/PPP/PPP-94.pdf
https://www.extension.purdue.edu/extmedia/PPP/PPP-92.pdf
The forces that a hitch pan can withstand are related to its design and size and can be measured by its tensile strength, yield strength, shear strength, and ductility.
Tensile strength is measured by pulling the ends of a pin in opposite directions to see how much force it can take until it breaks or fractures. Tensile strength is typically presented as pounds per square inch.
Yield strength measures the minimum load it takes to produce a permanent deformation (such as stretching or “necking”) to the hitch pin or bolt. Yield strength is typically presented as pounds per square inch.
Ductility measures how much a material can “bend” before it breaks. Ductile materials will bend before they break. Metals with low ductility are usually referred to as brittle. Metals that have been bent or distorted can exhaust the available ductility and become brittle from being bent or straightened. Ductility is typically presented as a percent.
Shear strength measures how much force a material can withstand before it breaks. While tensile and yield strength are important, shear stress on a hitch pin or bolt is more important in real-world transportation applications. Shear stress is a slicing action across the surface of a pin perpendicular to the axis of the pin. A hitch pin can experience shear stress across its entire length and at different angles depending how the wagon, implement, or trailer is sitting relative to the towing vehicle. The wagon or implement tongue can move forward and backward and even side-to-side.
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wfo9
New member
If you are using a regular strap and getting a running start at it you would be lucky if you just end up with the pin bent.... Running starts require a snatch strap to eliminate the shock loads. They decrease the forces dramatically. I think 1engineer posted some scenarios on this.
My entire point in all this was you have two different ways to connect. One is a pin and a strap. The other is a receiver + a pin + a shackle + strap. I feel the shackle is the weak point in a straight pull and can become airborne if it fails. This is the reason I avoid it unless it is necessary. For a side pull or some other awkward angle all bets are off and things are likely to go bad fast anyway. The other end of the pull may also require a shackle... But less is more to me.
I will try to read what you posted when I get a chance.
nevada
Senior Member
back before I had a winch/tires/properly set up truck etc, this was the GO TO method to retrieve someone. chains, straps whatever we had that was long enough. we broke lots of straps, never any vehicle parts. after so many broken straps, we started using chains, much stronger. still no broken truck parts.
then we had a chain break, and the hook flew back and broke the window of the pulling truck. we pretty much stopped using chains after that. but, still no broken vehicle parts related to the bumper/hitch etc.
still to this day, we use offroad recovery straps in a snatch type use. they are not snatch straps, but they have some/enough give. usually we aren't stuck THAT bad when we use them, so the rig starts to move, absorbing some of the shock. for bad stucks, we go straight to the winches now.
Mooney
New member
[MENTION=114439]Curly Jefferson[/MENTION], [MENTION=66316]1engineer[/MENTION], your facts are obviously getting in the way of our opinions!:tea:
I believe if the hard metal thingy hanging off the back of your receiver hitch can tear up your shin, then it's strong and should work great to pull out a stuck vehicles.
I believe if the hard metal thingy hanging off the back of your receiver hitch can tear up your shin, then it's strong and should work great to pull out a stuck vehicles.
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1engineer
Moderator
Sorry man. I understand how facts can ruin a good story lol. The older I get the better I was holds true too.
dekeman
New member
Not sure why I like that sentence so much.
And for Greg:
<iframe width="560" height="315" src="https://www.youtube.com/embed/ldQrapQ4d0Y" frameborder="0" allowfullscreen></iframe>
1engineer
Moderator
Absolutely.
