Safe load limit for chains

Submitted: Friday, Apr 29, 2005 at 08:24
ThreadID: 22474 Views:1696 Replies:7 FollowUps:12
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What's a safe load limit to get on a chain.

And where do I go to get the chain? CHEAP!

iMusty
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Reply By: Mike Harding - Friday, Apr 29, 2005 at 08:55

Friday, Apr 29, 2005 at 08:55
I didn't realise you were into that sort of thing? :)

How big is a chain? They're used to hold ships in place - but those chains are on the large side.

Black Rat (or somebody) do a 4WD recovery chain in a plastic pot for some silly amount of money – Rays sell them – take a look at that to get an idea of size required. Supercheap sell chain by the metre and the yellow pages should turn up any number of chain suppliers.

Loading? I guess any chain you buy from a proper supplier (ie. not Supercheap et al) will be tested for an SWL but how that would apply to the sorts of loadings when trying to recover a vehicle I'm not sure. Personally I'd buy the biggest chain Supercheap (or whoever) sell about 7 or 8mm diameter links from memory. The real advantage of chain in a recovery situation is that it won't turn into a flying scythe but just goes all limp and lies on the ground glaring at you :) Buy a few small shackles too so you can join it if it breaks.

Mike Harding

PS. Have you mentioned your new "interest" to Heidi :)
AnswerID: 108757

Follow Up By: Member - iMusty (VIC) - Friday, Apr 29, 2005 at 09:13

Friday, Apr 29, 2005 at 09:13
The chain wont fling! if it breaks.

Is that what you are saying? I like the sound of that.
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Follow Up By: Patrolman Pat - Friday, Apr 29, 2005 at 11:55

Friday, Apr 29, 2005 at 11:55
"Buy a few small shackles too so you can join it if it breaks."

If i bought a chain for recovery purposes and it broke I'd throw it away ang get a stronger one. I certainly wouldn't be joining it together with a few small shackles.
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Follow Up By: Crackles - Friday, Apr 29, 2005 at 12:13

Friday, Apr 29, 2005 at 12:13
"The real advantage of chain in a recovery situation is that it won't turn into a flying scythe but just goes all limp"
"The chain wont fling! if it breaks" You've got to be kidding!!!
You obviously have never seen one break. Witnessed one let go flying through the back window of a LandRover between the driver & passenger then smashing the windscreen. No one killed but damm close.
Chain should preferably be used in a static position (anchor points) to avoid shock loads or as a drag chain to get a bit of wood. These days there are far stronger & lighter fibre slings for use in recovery.
As for what size........ What do want to use it for? What weight do you want to lift/tow. There are different grades of chain so a 12mm elcheapo chain would not neccesarily be as strong as an 8mm Herc Alloy.
Cheers Craig............
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Follow Up By: Mike Harding - Friday, Apr 29, 2005 at 15:45

Friday, Apr 29, 2005 at 15:45
>You obviously have never seen one break. Witnessed one
>let go flying through the back window of a LandRover
> between the driver & passenger then smashing the
>windscreen. No one killed but damm close.

I've seen a chain break on only one occasion and it was a non event
but if you have witnessed the above and the chain was not connected to a wire or other type of rope then I'll stand corrected and withdraw my statement.

I am having trouble understanding the physics of the situation though... I suppose if a large majority of the links decided to expend their energy in the same direction it could happen otherwise I would have thought they would have tended to counteract one another and the chain would go nowhere?

Mike Harding
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Follow Up By: Frank_Troopy - Friday, Apr 29, 2005 at 18:54

Friday, Apr 29, 2005 at 18:54
There will be a catenary effect, if the chain is off the ground. The tension in the chain will straighten it's downward curve and lift the weight of the chain. When it breaks, the chain falls and curves and the broken ends move apart.

I can't see how this could produce any dramatic effect in our likely situations. What could possibly launch a chain through a car's back window? Surely there was something stretchy there somewhere, even if it was the part of the car it was attached to.

If I'm to change my mind about chains, I'd like to hear some more details about the circumstances and just what propelled the chain.

Cheers Frank.
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Follow Up By: Crackles - Saturday, Apr 30, 2005 at 17:17

Saturday, Apr 30, 2005 at 17:17
The chain in question that broke was a non rated drag chain hooked directly between 2 4bys with no other strap or cable. The plan was to tow a bogged G60 out slowly without gerking it but after it was recovered about a metre of slack developed in the chain. When the G60 stopped the Landy kept going at about 10 kph (didn't hear the stop signal over the CB) & the resulting recoil snapped the chain at the bull bar flinging it through the back window. A sobering moment for all.
The only other chain I saw snap was at work & like Mikes example was a non event.
Cheers Craig........
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Follow Up By: Frank_Troopy - Saturday, Apr 30, 2005 at 18:32

Saturday, Apr 30, 2005 at 18:32
Thanks Craig.

I'm going to be more careful in future.

Cheers Frank.
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Follow Up By: Crackles - Saturday, Apr 30, 2005 at 18:51

Saturday, Apr 30, 2005 at 18:51
& I thought our group were the only ones silly enough to snap a chain like we did but after reading the thread below it sounds all too common.
Cheers Craig......
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Follow Up By: Mike Harding - Saturday, Apr 30, 2005 at 19:00

Saturday, Apr 30, 2005 at 19:00
I think it was the gerk that caused the problem Craig :)

Thanks for the info. - I don't understand why this should happen with a chain being stressed between two items with minute elasticity but I accept what you say and will heed your warning - perhaps someone with a better grasp of physics than me can explain?

Mike Harding
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Reply By: BenSpoon - Friday, Apr 29, 2005 at 10:23

Friday, Apr 29, 2005 at 10:23
go visit your local slingrig or rigging/safety store.

The chain I have is 8mm, and whilst I couldnt get an SWL rating for it, nor could anyone at the slinging shops tell us. Apparently drag chain is different to any other standarad chains SWL. I was told it would be good for 4 tonne by a bloke at a safety store- and I havent found anyone that has said otherwise yet.

I found the pre-packaged chains were significantly more expensive than steel/rigging suppliers. Check your local one steel or fab shop too-
Its also worth getting one of each of the attachments- lug links, grab hooks and standard hooks- they all come in handy at some stage. I got an 8m and 10m and find the 8m is sufficient for almost everything.

Another option in the chain is getting calibrated stuff- more expensive, but you can grab hand winches for them that are dead easy to setup and you dont have half the hassles of a wire rope.

AnswerID: 108769

Follow Up By: BenSpoon - Friday, Apr 29, 2005 at 14:20

Friday, Apr 29, 2005 at 14:20
Stumbled across this: (specific to the type of chain advertised, obviously)

Chain Size mm Lashing Capacity Tonnes
7.1 3.0
8 3.8
10 6.0
13 9.0

* NOTE: The use of some grab hooks or systems incorporating grab hooks cause bending to occur on the link of lashing chain to which the grab hook is engaged. The bending and shearing effect of the hook reduces the strength of the chain by 25% and as such, the lashing capacity (LC) of this type of system must be reduced by 25%.
NOT TO BE USED FOR LIFTING PURPOSES
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Reply By: Exploder - Friday, Apr 29, 2005 at 12:15

Friday, Apr 29, 2005 at 12:15
Gday iMusty

Your standard quality 8mm chain should be good for around 2.5 ton.

I wouldn’t be using it for minor recovery or towing by itself though as chain has no give and you will probably damage something. If using it to tow id put some largish gauge rope in-between 2 lengths of chain so you get a smooth pull and not a jolt.

The only time I have used chain (logging drag chain) is for pulling out stumps and moving fallen trees with a Ferguson tractor at the hobby farm, and I would not recommend chain for 4WD recovery if that is what you r intending to do.
AnswerID: 108779

Reply By: Barnray - Friday, Apr 29, 2005 at 22:08

Friday, Apr 29, 2005 at 22:08
I was 3m away from a chain that let go one night, I saw the sparks when it broke and the imprint in a Hilux tailgate after. I was lucky that I had moved away,it could have done some real damage to my ribs. Don't make a mistake they can be deadly Barnray
AnswerID: 108868

Reply By: Matt (W.A.) - Saturday, Apr 30, 2005 at 00:18

Saturday, Apr 30, 2005 at 00:18
iMusty,
Is there any real need to use Chain? I’ve been in the offshore Industry for 13 years and there was a Total recall of all the Grade T Chain that we used for Lifting and Rigging Purposes due to Hairline fractures in a higher than average percent of chain slings, they require Re-certification if there dropped a lot and abused its a lot of hassle if you ask me. I know from Personal experience that chains don’t withstand the rigors of Dynamic load all that well compared to Synthetic Endless round Slings. there is a big weight Difference as well that you have to conceder! I have also seen the Sparks before the Break and the chain became one deadly weapon in my opinion! Would a tow strap suit your purpose or do you require a longer one they come in all sorts of lengths aswell I have seen them atleast 20m long but I would definitely speak to a Rigging Company like Sling Rig (If there Still Around!) or Aker Unirig or Bullavaunts.

All this is my own personal opinion!

HTH
AnswerID: 108881

Reply By: Member - Frank - Saturday, Apr 30, 2005 at 00:50

Saturday, Apr 30, 2005 at 00:50
chain will not only break it will kill I assisted a farmer remove a stump from a washout on a road I was on the tractor lowest posible gear a real crawl it was a large link at least 80cm it took the strain then snaped came back over the fuel tank leaving eight of an inch groove in the quarter plate steel, smashed my colar bone and through me over the bonnet, and we never even jerked on it

it parted on weld, any chain is only as good as the weld and it makes no diference if it has been tested because that very test may have weaked the weld

if you intend to take the darwin award just make sure everyone else is clear because it will break eventualy given the right circumstant, the car your pulling stalls and doubles the strain, the car your pulling surges forward then drops back this will do it everytime

cable will shred and lose some momentem but will still whip

nylon will whip but is at least light

I found the best was a snach strap but dont snatch just rock the vechical

or my favourite set up camp and dig or raise it up but then I do not go near the alps, desert forever

frank

ps this is no joke 3 months. shoulder reconstruction. concusion all for doing something I would have never done normaly just trying to help

AnswerID: 108885

Follow Up By: gqpat - Sunday, May 01, 2005 at 20:48

Sunday, May 01, 2005 at 20:48
TRY going to the Bullivants or pwb? web sites they should have calculations for chain swl you will need to know dia and grade if the chain is of any decent manufactor its grading should be marked if not i wouldnt use it
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Reply By: hoyks - Sunday, May 01, 2005 at 21:41

Sunday, May 01, 2005 at 21:41
I got a 5m length of 3/8" truckie tiedown chain with some rated hooks. I got it from a feed store near where I worked in Townsville, and it was quite cheap compared to the pre made ones in the 4x4 shops.
I only occasionally use it as a load equaliser when winching as I prefer nylon for every thing else. It is lighter, easier to work with, easier to spot damage in and kinder to the delicate hands.

But you can't beet a chain when it comes to skull dragging a log back to camp for a good fire.
AnswerID: 109137

Follow Up By: hoyks - Sunday, May 01, 2005 at 22:02

Sunday, May 01, 2005 at 22:02
As Frank was saying, I saw a video of a chain letting go in similar circumstances. Some clown was trying to pull a stump using the family car and the chain let go and flicked up in a nice arc, straight through the back window.
I think it was on Funniest home videos, but like most things on that show, not real funny.
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FollowupID: 365849

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