TEST: Towing Safety Chain Shackles - what do they break at?
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- Опубликовано: 30 апр 2023
- #towingshackles #shackles
If you tow, then you need at least one safety chain connecting the trailer to the towcar, or two if the trailer is more than 2000kg GTM. There are regulations around the strength of the chain, and shackles; what exactly are those regulations, what's legal and what's not, and how strong is a rated shackle compared to an unrated shackle?
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Great video and very interesting results. Thanks Dr Pepper.
Another great video Rob 👍👍👍
Thanks for the brilliant comparison , all numbers including the price difference . Noticed your assistant didn't turn the pin back approximately half a turn , when you have a 200 tonne crane in action struggling with a shifter etc is expensive. Re loose pins , a rigging term is "mousing" which is done with some fine wire , that's probably why the hole is in the pin . On bosuns chairs the shackles must be moused , also slings are moused to the hook so they are held in the cup of the hook and can't flick or bounce out .
Your presentations are much appreciated , thanks again .
Thanks, please share!
Great to have the state by state regulations on minimum WLL rating for towing shackles. Great work again, thank you!
I didn't include them all, but they agree on the SAME CONCEPT but use DIFFERENT WORDS AND EXAMPLES AND MANDATES. So, so annoying.
This is so good and drives home why you need to make sure you purchase correctly rated shackles.
For the price difference why wouldn't you.
Very interesting. Thanks for that insight.
Great video! Thank you for sharing 😊
Thanks for watching!
Been hoping you might do a test like this. Thanks for going to so much trouble 👍
You're welcome, please share!
@@L2SFBC Done
Brilliant, thank you. Very interesting difference between the two, I had always assumed the main difference to be quality control, testing and certification rather than a physical difference. Couldnt have been more wrong.
Glad it was helpful!
Great efforts thanks
Some rated ones I have are with very rough or even sharp edges, especially on markings. They are no good for connecting something like synthetic lines while being ok for metal to metal contact. In such case unrated smooth one can be actually better (assuming known specification and enough safety margin). I never buy one even for general low risk use unless it has a known manufacturer specification. I have for example some that I marked based on specification for 63kN that should be safe for eg. lifting a ton (with 6x safety margin).
In climbing I use only ones that may not be as much specified but that are all individually tested. There a failure of a single piece is a sure death. Individual testing makes sure there can be no random manufacturing issua like a hair fraction inside that one cannot see.
Interesting video and a good reminder that it is not all about if it breaks. Deformed ones are no good for later use and can be difficult or even impossible to get open.
Ripper content again mate!
Thanks James
My curiosity is more in the swivel links you attached the shackles to. Here they are referred to as Hammer links as you have to hammer the pin into them. The reason for my curiosity is that RAM and Ford trucks here in the US with factory hitch receivers have holes for the safety chain hooks that are too small for the hooks used on almost all trailers. Its very common to see the hammer links dangling from the receivers to provide a place to attach the hooks to. I see the hammer links are quite strong.
Great video - thanks. We hire out trailers regularly where I work and won’t let customer leave using unrated shackles - I’m in Vic and I get the ‘they don’t have to be rated’ argument all the time but not sure what the COR laws would say if I let them go and an unrated shackle failed if the trailer came off - I will always lend them rated shackles. I’ll be sure to send them a link to this video next time I get any lip from them. 😊👍
The ‘Oldmate66’ made me laugh out loud - there are hundreds of those keyboard warriors banging away right now with a frown on their faces. 😂
In Vic the shackles *don't* need to be rated, but for the sake of $0.50...why would you? And, then you'd need to prove the shackle is 1.5x ATM. Funnily enough the easiest way to do that is to have a rating on the shackle...
I would like to see those yellow hooks tested, that would be interesting
Get some rear cuts of 200 series, ranger bars ect... bet the attachment point on the vehicle or tow bar fails first and with less force
10:20 not the shackle, but the bolt. The shackle might deform, but the bolt is the main issue.
It's the pin that's rated, that's why they're coloured.
Do a follow-up test on trailer chains. Where is the weakest link?
I bet it's the point of attachment to the vehicle...
A 200 for example with 3.5t which many do a gcm upgrade and van can be 4t...
Have a look at the attachment point... 😂 that would not hold 4t or even 3.5t...
Hopefully can do on the sling hooks that some use and some trailer and 4wd shops sell as trailer connectors, are legal or safe fit for purpose
I would like to see this too. I don't see how they could be considered safe to use as the latch is a weak point if the trailer bounces around in an emergency situation!
I understand the reason for the small sized shackle was needed for the testing machine, but wouldn’t a larger shackle, which would have a higher working load and max load limit, would that not mean the percentage of the two increase quite a bit more? Say it’s rated for 5 ton. Then to keep that safety margin factor of 6, that’s a max load of 30 ton.
Then factor in shock loading…
just doesn’t seem like there is a good reason to not go bigger on shackles.
Also straight from Wikipedia, “a safety factor, usually ranging from 4 to 6 on lifting equipment. The factor can be as high as 10:1 or 10 to 1, if the equipment poses a risk to a person's life”.
Well you can go bigger on shackles but what's the point? The 1t rated shackle didn't break at 6.5t, and there's two of them for a 3500kg trailer. I'd suggest that if you had forces such that a combined total of at least 13t of shackle, probably 15t, were broken then the strength of the shackle would be the least of your concerns. I did a shock load calculation in the video.
16:30 that shifter went in the wrong way. Like a pipe wrench, there's just one way.
My only thought about the Australian common shackle design is that you can't see if it's actually tight just by looking at it from a distance. I've seen others where the threaded end extends and an R clip on the end to prevent the pin from working loose. The common D shackle is a cheap and effective design but there are downsides. With corrugated roads, maybe the safety pin shackles might be the way to go?
Yes, provided they're rated, they work. In the video I noted that shackles should be oriented so they don't work loose, which mostly means thread down.
Could you explain again how you stop the pin from working loose with vibration? I watched the video but can't see where the explanation is.
It's not explicit but I show my shackles are thread-down in a closeup. This means that gravity helps keep them done up. Mentioned in the summary too.
If you are worried about the pin working loose mouse it with wire or a cable tie
@@ianmoore4327 Exactly! I was just thinking safety wire.
Also, @paulsorrentino5475 they do make shackles with a straight pin and cotter pin, but don’t use those, the threads allow the pin to deform quite a bit before failure.
Unrated shackles are manufactured in factories with limited quality control and for a market that doesn’t care about buying a quality product. Manufacturing to a standard is more expensive and the product is more expensive. Buy whatever suits you but don’t winge when the product fails to perform.
Great video!
I'd love to know your thoughts on "hooks" for towing. So many people giving different theories. It's hard to even find an answer from the appropriate authorities.
No need for theories. The state authority has stated what the requirements are - meet them, and you're good.
My reading is the hooks pass static load testing but are not 'rated' for shock loading.
My theory is, any bit of kit that doesn’t meet regulations gives insurers leverage to deny claims arising from an incident
Pins appeared fully tight before 100% load rating test. Usual guidance is that they should be left slightly loose to allow easy untightening. There should be no need for spannering up to rated loads
Barely finger tight. The reason the spannering was needed was because of slight deformation.
@L2SFBC Yes, that is the idea of leaving some slack when assembling. You could see the test operative not undoing slightly after fully screwing in the pin.
What does the yellow mean? Mine have a blue bolt but are rated and stamped.
It appears that the unrated shackles have a smaller diameter pin, no? It seems to me that this wouldn't exactly be an "apples to apples" comparison if so. That said, I still wouldn't use a shackle of which I didn't know it's limits.
yes, smaller diameter. But same overall size, so fair.
Great video 👍
Would you happen to have the link to the NSW regulations or be able to tell me what they are?
nowhere on the Internet that I could see, sorry
Let me re type that. For your demo it probably makes no difference. But the pulling load should be on the U part & not the bolt part. If you know what I mean.
It's in tension so doesn't matter
💪💪💪
At 6:13 the underrated shackle was tighten up too much, resulting a tool was need to be undone.
Certain loads placed on the pin of the shackle on certain angles will cause the pin to roll and tighten every time
Isn't that realistic though?
@L2SFBC for testing purposes/ no vibrations etc a loose pin may have given you a better indication if the thread binding part of the test, but yes you're correct, we are all guilty of doing up the pin so it doesn't vibrate out at some stage, which might I say is far better having a fractionally over tightened pin than having the pin fall out during travel and end up have no shackle at all..
I see a few shackle pins lying around on the roads at times, especially near speed humps
Yes and I also noted in the video to mount shackles in a way such that the pin doesn't fall out. In normal operation there would be no stress on the shackle so it should undo fine even if tightened hard...if there has been tonnes of stress on it, then I submit getting it undone is not the biggest concern one would have at that time :-)
Interesting test. I would have guessed the screw threads deforming would be the biggest issue.
The pin bending and still be removeable, shows a large tolerance in the screw threads. Didn't think of it before, but perhaps shackle designs with the R-clip aren't a bad idea if used on rougher roads. Oldmate66 probably has been shouting this from the digital rooftops for years.
My tow vehicle, in Australia, is rated to tow 3.1T, but I cannot get a D shackle greater than 1.0T to fit through the holes/mounting points on my factory fitted tow bar. If I'm towing a caravan greater than 2T ATM, am I legal coupling it to my vehicle with 2 x 1.0T D shackles? I'm confused. I assume that I need 2 x 1.5T D shackles, minimum, to my tow vehicle to be legal. But then I may travel to ALL states in Australia, so where do I stand??
Unrelated to this video, but I'd be interested to hear your thoughts on the new offset recovery ring that Yankum ropes came out with. Casey Ladelle did a video on it recently. Some people have criticized that it or the soft shackle will be overloaded and damage the winch line when doing multi-line pulls.
I don't like the design. It shifts stress from the shackle to the rope. Reason given i to reduce heat in the rope which was never a problem anyway.,
@@L2SFBC Seems to me that it would add a lot more resistance, lowering your mechanical advantage too. Thanks for your input.
thanks , this was very interesting. can you clarify. when you say 1.5x atm, how does this relate to having 2 chains ( clearly one shackle per chain) ?
The regulations do not differentiate between 1 and 2 chains. I would play safe and say each shackle should be 1.5x ATM.
I’m about to purchase my first camper trailer and it’s approximately 1.5T ATM. What would be the shackle requirement be for that load? It has 2 chains
Stand by for a video on this specifically
How does this translate to a galvanised boat trailer
Rated shackle vs unrated is a no brainer...the results are hardly surprising
Galvanising compromises the union between the drawbar and the chain as well as the chain itself.
This test should be redone with a more real world test, eg, Mocked up trailer drawbar and tow hitch eyelets
&
Your applying a constant load not shock load
Love to see that test !
Sadly there are no machines that will shock-load, least none I can find and afford. I did however calculate a shock load, and note that there would be two shackles so say about 60% of the load on each. I don't see why the trailer drawbar or tow hitch eyelets would need to be mocked up?
The eyelets are plate steel with holes on a large percentage of towbars so they concentrate the force to quite a small contact patch eg the thickness of the plate
I purchased a new boat trailer this year that came with 1 only chain and non rated shackle
This is a 1000kg ATM so not huge but still surprising
It was from one if the largest boat trailer manufacturers in Aust
I question the shock load as it would be interesting to see if the rated shackles were more "brittle" but can appreciate testing this would be difficult
Thanks for the videos
Shackle bolt - twist finger tight then undo an eighth of a turn? That's what I was taught. That said, I only use rated recovery equipment.
You don't want trailer shackles to come undone, and there should normally be no force on them so do them up tight. If there is significant force, then, well, undoing them isn't probably your biggest worry at that point :-)
Yeah, I'm going to get rated shackles.
What would 6 tons "jerk" do to a towbar and chassis?
Mate66 is really nice.
6 tonne jerk would be a little...damaging :-(
@@L2SFBC So perhaps we want some flex and deformation in the shackles?
yes, an argument can be made that way.
@@L2SFBC So I'm thinking for my setup - a 1.9T camper..what I will do is get the rated shackles to replace the current un rated shackles and use the un rated shackles to bypass a link or two on the chains...a little like the idea of a crumble zones.
I note too that you spelt metric ton as tonne...I had better pay attention next time- thanks!
The should be on the body of the shackle not the bolt
What was the load rating for the hamerlocks?
Didn't test them. However, they should have a breaking strength as per the regulations shown. Easiest way to prove that is AS2741. certification.
@@L2SFBC Is it legal to use Hamerlocks?
And the hooks I now see everywhere attached to the hammerlocks. Would love to see them tested
Excuse me Mr Pepper. I went to Bunnings a few months ago to get a rated shackle and they had a fairly large section of Shackles, and EVERY SINGLE ONE had a tag saying that they are not rated. Even the ones with a coloured bolt, including Yellow. I would NOT suggest Bunnings and in fact Bunnings needs to be CALLED OUT for selling unsafe shackles to customers who don't know better.
www.bunnings.com.au/pinnacle-10mm-galvanised-d-shackle_p2260235
The unrated shackle, which size was it?
Same as the others
@@L2SFBC
Thanks, so a cheap shackle will hold about half the load of a rated shackle.
Is the press pulling up or down?
up
That is well & good, but you are using the shackles the wrong way round
Why so?
I am a tad concerned the gear used to test to a standard, is still using Windows 95/98.
It's very common - the software tends not be updated and therefore reliant on old operating systems. Another good example is old tech-heavy sports cars which need old laptops to operate them.
@@L2SFBC Given i work in the industry, i do see some rare examples of this, i could understand maybe Windows XP. Windows 95/98/NT is just absurd. Begs the question for me, does the company not want to spend the money to update to the latest tech? Can we rely on the results given the legacy hardware, and software that most likely hasn't been updated in maybe 20 years? Yes that machine/hardware may only run on that platform, i cant see any good reason to still use it in 2023 for any reputable organization. There are no doubt industry standard hardware and software platforms that meet current requirements, why not use them ?
OK so you'd know that test rigs like this have specialised interfaces and therefore specialised drivers. And that drivers written for Windows 9x won't work on XP as one has a DOS-based underpinning and the other is Windows NT. That's my guess as to why it's an old OS. Can we rely on it? Well, if the same software has been in use for 20 years, my guess it's been used a lot and nobody has noticed any errors so I'd say yes, reliable. I'm only speculating though.
The operating system etc is irrelevant. The only thing that matters is the accuracy of the equipment. These systems are tested to ensure accuracy and certified compliant 1-4 times per year. Plus they do their own calibration tests as well. Better to have an old solid version of an OS that you know works than a flash new buggy version.
The rated shackles are of a larger diameter than the unrated shackles so you are not making a fair comparison. Weight of material is key. If diameter is the same and weight is different, the heavier will most definitely be stronger. Your test was not accurate or conclusive. I do not like posting negatively, but this test was not done accurately.
Heavier is stronger - not necessarily. Strength also depends on construction as well as material strength. I think the test was fair as the two shackles were very close to the same size and people do use unrated of that size, which is why I chose them. Even the rated shackle is slightly larger diameter on the pin, say 5%...it outperformed the unrated by way more than 5%.
If they were the same size, weight etc they'd probably both be rated.
Type of material will effect the WLL, for example a grade M shackle (mild steel) will be approx. twice the size for the same WLL “S” grade shackle (alloy, and most common type of material)
At least get 2 shackles that have the same size pins. What a waste of time.
Why is a total waste of time?
@@L2SFBC So i have an 8mm bolt and a 10mm bolt, guess which one is stronger. Measure the shackles pins and let us know the sizes.
Are the 8mm and 10mm the same construction and type of material? Can the body be the same size too, or just the pin...because it's different rated to unrated.