D shackells
Submitted: Saturday, Sep 08, 2012 at 16:19
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tony&bron
Gooday what size d shackle is needed on the safety chains of a 3 tonne gtm caravan
thanks in advance
tony
Reply By: Shaker - Saturday, Sep 08, 2012 at 16:31
Saturday, Sep 08, 2012 at 16:31
Generally ones the same size or rating as the safety chains.
AnswerID:
494500
Reply By: dindy - Saturday, Sep 08, 2012 at 16:42
Saturday, Sep 08, 2012 at 16:42
Hi tony&bron, without trying to sound flippant, perhaps the biggest shackles you can get through the chain link. I am a great believer in overkill. It never ceases to amaze me that people will connect their camper/caravan safety chains with the smallest unrated shackles they can find and expect that when their van separates from their tug it will be retained by a couple of mild steel loops.
I would try and find a set of load rated shackles that are at least the same cross section size as you safety chains. Load rated indicates the safe working load of the shackle.
AnswerID:
494503
Follow Up By: graham B9 - Saturday, Sep 08, 2012 at 19:28
Saturday, Sep 08, 2012 at 19:28
Dindy is right. Get the biggest one that will fit. Stainless steels even better for rusting but gal are alos OK.
There are 2 types "Buoy" is the most common but "Bowed" are stronger. Just google them and you will see the difference.
Have a look at "Grays Online" and the cheapest place I have seen for them. Do not go to a marine
shop as they are generally expensive. ie Fishing, sailing and camping stores are exoensive as
well.
http://www.graysonline.com/lot/0118-5003895/manufacturing/4-x-bow-shackles-wll-1-5t-screw-pin-type-grade-s-yellow-pin-buyers-not?spr=true
Follow the link above and it is for 4 shackles at an auction.
Check at the delivery cost as you might be a long way away. Currently they cost $9 for a set of 4. Cheap as chips.
FollowupID:
770159
Follow Up By: Skippype - Saturday, Sep 08, 2012 at 20:17
Saturday, Sep 08, 2012 at 20:17
I also agree about size. As long as they are rated.
Skippy
FollowupID:
770162
Reply By: blown4by - Saturday, Sep 08, 2012 at 21:40
Saturday, Sep 08, 2012 at 21:40
You need shackles that are the same rating as the safety chains. Don't worry about the 'biggest that will fit through the chain' or stainless steel (which are usually a lower SWL rating than steel). The biggest that will fit is useless if it is made out of crap steel (from China)
If your CVN has a GTM of 3000kg then the safety chains should be marked AS4177-35 which means they are made to an Australian Standard, will be 12mm diameter and have a SWL of 3500kg. Use shackles with a marked SWL of 3500kg and you won't go wrong. If they have no markings they are not 'rated' therefore the quality is suspect. You may need to go to a 'lifting gear' store to get them and they may cost you a few bucks but remember it is the shackles that attach the safety chains to your car and you want them to restrain your pride and joy in the unlikely event that it becomes detached.
I shudder every time I see caravans attached using padlocks or those stainless steel yacht 'spring loaded clips'. Should the van come off the hitch they will just pull apart and leave the van sailing down the road unrestrained until it hits something or somebody or the breakaway brakes pull it up (whichever occurs first)
AnswerID:
494521
Follow Up By: david s27 - Saturday, Sep 08, 2012 at 21:48
Saturday, Sep 08, 2012 at 21:48
chain dia [mm] x dia [mm] x 30 x . 4 = KG/SWL
EG 12mm x 12mm 30 x .4 = 1728 KG safe working load /SWL [1.728 tonne]
Cheers
FollowupID:
770164
Follow Up By: Member - Wamuranman - Sunday, Sep 09, 2012 at 08:38
Sunday, Sep 09, 2012 at 08:38
Thanks David that's a useful formulae to have.
I just checked
mine.....they are 12mm chains on van (x 2)
My D-shackels are 16mm WLL 3.2T F S NV30.
So it would appear my D shackles are rated at almost 2 times the chain.
(I use each chain separately crossed over to opposite side of tow-bar).
Cheers
FollowupID:
770189
Reply By: Rangiephil - Sunday, Sep 09, 2012 at 09:42
Sunday, Sep 09, 2012 at 09:42
Bullivants is a good place to buy real rated D shackles or Bow shackles.
I am often surprised to see unrated /unstamped shackles provided by caravan manufacturers with new vans! Although I suppose I shouldn't be,considering the many atrocities I hear talking to van owners in parks , like towball weight being 180KG rather than the stated 140Kg, forcing the new van owner to have to buy a new car as
well!
Regards Philip A
AnswerID:
494547
Follow Up By: Shaker - Tuesday, Sep 11, 2012 at 09:46
Tuesday, Sep 11, 2012 at 09:46
Most manufacturers don't use rated chain, so not much point in using rated shackles.
FollowupID:
770326
Reply By: Hairy (WA) - Sunday, Sep 09, 2012 at 10:58
Sunday, Sep 09, 2012 at 10:58
Gday,
Some of the info your getting might be a bit misleading I think?
Im not sure how you can use any sort of formula to work out SWL without knowing exactly what sort a steel it is?
And the biggest shackle that fits through isnt much help either I would have thought...........you could have high tensile 4 ton chain that will only take a 1 tonne cheapie shackle?
Find something like this on the web, taken from the State its registered in........
•trailers over 2.5 tonnes and not exceed 3.5 tonnes ATM must have two safety chains of designation of 3500 kg complying with Australian Standard AS 4177.4-1994 or Australian Standard AS 4177.42004;
Dont confuse ATM with GVM..........
If your in WA, this might help......
LINK
Cheers
AnswerID:
494555
Follow Up By: Member - Wamuranman - Sunday, Sep 09, 2012 at 13:16
Sunday, Sep 09, 2012 at 13:16
Hi,
I just had another look at my chains (near new caravan)- the inscription appears to be "BR4177-35". It is 12mm thick links.
Does anyone know if that is compliant with the 3500kg standard?
The problem I had was finding D-shackles of 3500kg where the lug or centre pin would go through the chain.
I found it impossible to find a 3.5 t one that would.'But I found a 3.2t one that just did fit with a little help.
I bought them from a truck accessories place (Diesel Spares) and were I recall $17 each so I am assuming they are good quality.
Cheers
FollowupID:
770212
Follow Up By: david s27 - Sunday, Sep 09, 2012 at 13:20
Sunday, Sep 09, 2012 at 13:20
the formula is for mild steel lifting chain which should be the min that is used for safety chains . if it is a higher grade then you substitute the 30 for the grade [30-100] and the then apply the right dec point being either .3 / . 4 depending on the grade..... if you use bunnnnny specials then there is no formula as they are only made out of "crap iron "..I can put all the formulars on sit if needed , but that would be little over the top!!!!
Cheers
FollowupID:
770213
Follow Up By: blown4by - Sunday, Sep 09, 2012 at 15:08
Sunday, Sep 09, 2012 at 15:08
Just stick with VSB1 which is the national standard applicable in all jurisdictions throughout AUS and you won't have any problems.
AS4177-35 chain is 12mm diameter and 3500kg SWL
AS4177-25 chain is 10mm dia and 2500kg SWL
AS4177-16 chain is 8mm and 1600kg SWL
AS4177-8 chain is6mm dia and 800kg SWL
Don't forget if you have two chains each must be rated at the trailer full GVM (not 1/2 each)
Chains with BS4177 do not comply as AS4177 atr the only marking accepted under VSB1. I would
hazard a guess that the BS4177 chains are from China as they are very adept at marking things with the marks the authorities want to see but it does not mean the item complies with that standard. 3.2t shackles are no use on 3500kg chain unless your trailer is less than 3200kg. If the 3500kg SWL shackles won't fit through the 3500kg chain then I would consider the chain suspect. All these items when made to meet AS4177 WILL fit together as that it the way they are designed. Price has little to do with quality.
FollowupID:
770218
Follow Up By: Crackles - Sunday, Sep 09, 2012 at 19:23
Sunday, Sep 09, 2012 at 19:23
"3.2t shackles are no use on 3500kg chain unless your trailer is less than 3200kg"
I wouldn't say that. 3.2 Tonne is the safe working load but the actual breaking point of a quality D can often be 8 times that. In one NATA
test I read, a 3.2 tonne D distorted at 28 tonne! More than enough I'd suggest to control a 3.5 tonne van & far stronger than the weld holding the chain to the drawbar ;-)
Cheers Craig.............
FollowupID:
770239
Follow Up By: Member - Wamuranman - Sunday, Sep 09, 2012 at 19:57
Sunday, Sep 09, 2012 at 19:57
Here is the Safety Chain Shackle Matrix...it would appear there is no such thing as a 3500kg compliant shackle anyhow. Probably why the truck people sold me the 3200kg one (
mine is 16mm, has "S" on it, and WLL of 3.2T). Anyhow as stated above they are designed to withstand 6 times their rated capacity before deforming.
Safety Chain Shackle Matrix
Quality Grade
Diameter WLL Marking
(mm) (kg)
6 250 M or 4
500 S or 6
8 750 S or 6
10 500 M or 4
1000 S or 6
11 1500 S or 6
13 750 M or 4
2000 S or 6
16 1500 M or 4
3200 S or 6
19 2000 M or 4
4700 S or 6
22 3000 M or 4
6500 S or 6
25 3800 M or 4
8500 S or 6
29 5000 M or 4
9500 S or 6
FollowupID:
770241
Follow Up By: Hairy (WA) - Sunday, Sep 09, 2012 at 21:40
Sunday, Sep 09, 2012 at 21:40
What a load of snot..........LOL
Just get a rated shacklle to the recomended SWL as advised by your transport authority, and ignore all the trumpet blowing bleep .
Hahahahahaha................
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Follow Up By: blown4by - Monday, Sep 10, 2012 at 21:29
Monday, Sep 10, 2012 at 21:29
Here, here:-)
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770305
Reply By: ozjohn0 - Sunday, Sep 09, 2012 at 15:05
Sunday, Sep 09, 2012 at 15:05
The SWL of the shackle must be at least 1.5 times the ATM of the trailer.
State registration authorities may specify GVM in Lieu of ATM. For trailers they're both the same.
Do not confuse with with GTM.
Ref: VSB1- ADR 62/01 & 62/02
Ozjohn.
AnswerID:
494572
Follow Up By: blown4by - Sunday, Sep 09, 2012 at 15:12
Sunday, Sep 09, 2012 at 15:12
Sorry but you are incorrect. The SWL of the shackles must equal the SWL of the chain. Why should the shackle be 'at least 1.5 times ATM of the trailer'? If that were true you would never get the shackle pin to go through the links in the chain.
FollowupID:
770220
Follow Up By: ozjohn0 - Monday, Sep 10, 2012 at 09:43
Monday, Sep 10, 2012 at 09:43
Have a read of the references I've given in my post.
OJ
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770262
Follow Up By: blown4by - Monday, Sep 10, 2012 at 21:53
Monday, Sep 10, 2012 at 21:53
OJ, I am familiar with all three of those documents. Can you give me clause number because I am unable to find any reference that states: "The SWL of the shackle must be at least 1.5 times the ATM of the trailer"
Happy to stand corrected if I am mistaken but I cannot find those words. Thanks.
FollowupID:
770307
Follow Up By: ozjohn0 - Tuesday, Sep 11, 2012 at 09:44
Tuesday, Sep 11, 2012 at 09:44
Mate, I'm the first to agree that when it comes to chains and shackles it's a minefield of confusion and myth.
As the attachment shackles form part of the tow bar and not the chain (As detirmined by Department of
Infrastructure and Transport) they are covered my AS4177.1
AS4177-1 section 5.5 stipulates attachment point strength requirements of 1x"D" value and 0.5x"V" rating of the tow assembly
Having regard to the above points the shackle should be rated equal to or greater than this rating.
Cheers OJ
FollowupID:
770325
Reply By: Daniel W2 - Sunday, Sep 09, 2012 at 19:04
Sunday, Sep 09, 2012 at 19:04
Good evening T&B,
Hows your head......Spinning?
Simple answer, I would go 3.2T Grade s Bow shackle.
There is some good info and bad info mentioned so i wont get into it.
If you are near Sydney/
Newcastle give me a ring 0438886120 and i can fix you up with some.
Cheers Daniel
AnswerID:
494593