Caravan Chains

Mr Red · Veteran Member

Caravan Chains

oldbobsbus · Guru

So long as this is the type of joiner you had inmind there shouldn't be any problems.. smile

Baz421 · Guru

I think from memory it was illegal to join chains,,, they must be one continuous link,,, however it may have changed.

I will look further.

Baz421 · Guru

Baz421 wrote:
I think from memory it was illegal to join chains,,, they must be one continuous link,,, however it may have changed.
I will look further.

Ah checked my references VSB1 and 3 states legislation - can't find anything that says you can't join the chain.

KFT · Guru

I think Bobs pic is of a hammerlock which is designed to join chains and if rated the same as the chain should be no problem

frank

SnowT · Guru

The Hammer Lock is only way you can join chain's that take a Load.. They must be Rated higher/the same as the chain..

The 3 formula's for working out chain load's..

1.
Grade (G)
80 Lifting Chain
D²x32=SWL

2.
Grade (G) 30 to 75 Lifting Chain
D²xGx0.3=SWL

3.
Flexible Steel Wire Rope
D²x8=SWL

For example Standard chain of 10mm has a safe load of 800kg..

The chain on a Camper/caravan is there to help control the trailer if it come's off the coupling.. Not as a mean's of towing the trailer, it protection only..

Juergen

rockylizard · Guru

Gday...

Thanks for the formulas Juergen.

However, it means absolutely nothing to me (I am not too bright obviously)

The 3 formula's for working out chain load's..
1.
Grade (G)
80 Lifting Chain
D²x32=SWL
2.
Grade (G) 30 to 75 Lifting Chain
D²xGx0.3=SWL
3.
Flexible Steel Wire Rope
D²x8=SWL

What does D² stand for? where did the numbers 32 & 8 come from? what does G stand for? How do I identify a "80 lifting chain" or a "30 to 75 Lifting Chain"? What 'size' chain is usual on a caravan? Will that chain have some visible 'rating' stamped on it?

I assume SWL stands for Stated Working Load?

And given those formulas, against what do I apply them? Will the answer (SWL) be readily visible on any shackle/joiner/hammer lock? Where can I buy the required 'joiner'? Would Bunnings be a supplier?

Cheers - John

SnowT · Guru

hey John..

Ok I had a Look your figure's are correct.. For a Hammerlock I would go higher in rating.. so that the chain is the weakest link..
Make sure that the there is no wearing on the link's of the chain.. [No dragging on the ground] if it has lost 10% of it diameter it should be replaced..

J
--------------------------------------------

http://www.nobles.com.au/Home

The very best Website for any information on chain's sling's or any form or lifting/restraint gear..

--------------------------------------------

If there are NO marking's on the Chain NEVER assume that the chain is Rated any higher rating..

So for example.. a 10mm chain you buy from bunning's.. with no marking's..

10x10 x 8 = 800kg..

------------------------------------------
Now say the chain has a G3 on it..

10mm G3 = G30

So the formula is
[10x 10] x30] x.3 = SWL
so 900kg..
-----------------------------------------
Now the chain is 10mm with a G8 or G80 or G10[100] or just a "T" on it..

[10x10] x 32 = SWL
So 3200kg..

Hope that help's.. you..

SO NEVER EVER ASSUME that any chain is a G8 or "T" rated chain..

You are far better of taking it as the lowest rating..

Juergen

-- Edited by SnowT on Tuesday 26th of November 2013 10:04:33 PM

MaryJane · Senior Member

What about a chain supplier? Or industrial supply outlet? To do the maths for you?

Or in my case, my trusty rv fixer, then I run it by another one, to see if I get the same advice....

Just a thought, cos I'm not real flash on the techno stuff.

SnowT · Guru

Sorry.. I have a Little bit of knowledge of chain's and sling's as such from the courses I have done rigging/dogging and The Trusck driver Course..

SWL - Safe working Load..
D = Diameter of the chain.. ie 10mm cross section..

Check to see if there are any marking's on the chain's They should gave a marking of some kind..

8 = the Best.. [ Use the top Formula 1]

3-7 lesser grade.. [Use Formula 2]

nothing.. Normal chain [Use Formula 3]

Hope this help's and that I have not left any More info out..

Juergen

rockylizard · Guru

SnowT wrote:
Sorry.. I have a Little bit of knowledge of chain's and sling's as such from the courses I have done rigging/dogging and The Trusck driver Course..

SWL - Safe working Load.. Thanks - gotcha
D = Diameter of the chain.. ie 10mm cross section.. So in the formula you supplied is Diameter is squared?

Check to see if there are any marking's on the chain's They should gave a marking of some kind. On my chains (that came with the van when new) it says PWR 4177-75 and is 12mm diameter. So in my case does the formula go as - 12X12=144X75=10,800X0.3=3,240Kg? My Van's ATM is 2,600Kg (over the scales)
8 = the Best.. [ Use the top Formula 1] So 8 = 80 in your formula?

3-7 lesser grade.. [Use Formula 2] and 3-7 = 30 to 75 in your formula?

nothing.. Normal chain [Use Formula 3] Confused here. So diameter squared X 8 (where does 8 come from?) produces "nothing"?

Hope this help's and that I have not left any More info out.. So help me here - how do these formulas help me decide on which size/rating of "hammerlock" joiner to buy/use. Does it mean I need one rated to 3,240Kg? Are these hammerlock joiners generally widely available and at which suppliers?

Juergen
Cheers - John

oldbobsbus · Guru

Hi John,
Like you I have NFI about all the tech jargon being thrown at us by those that have to sound as though they know everything...LOL..

IF I had to buy a joiner to suit a particular chain I would buy a hammerlock one with the same diameter as my chain from our local Skipper Aust store.. or any other good industrial bearing shop should have it in stock..

D and D · Guru

I reckon there's a fair bit tied up in the van and the safety chains maybe the last resort in keeping it so I get it all checked out by a reputable supplier of industrial slings such as Nobles. It's not just the weight of the rig but also the safety margins and if saving a couple of hundred dollars is more important than loosing your rig then go for the cheap option and guess. Otherwise take Juergen's advice and take the time to learn or get someone who does know how to do it do it for you.

ozjohn · Guru

VSB1 states chain, not chain, joiner, shackle, or piece of fencing wire. Just chain.
However correct size Hammerlocks are approved within the engineering, rigging, maritime and construction industries as a recognised method of of joining chains for lifting and towing purposes, but not however approved for use with chain blocks etc.

I don't know any engineer that would not pass a trailer being inspected where a hammerlock has been used to join the chain(s), but they wouldn't pass inspection where shackles had been used to join a chain.

Cheers, ozjohn.

-- Edited by ozjohn on Wednesday 27th of November 2013 12:46:30 PM

littledick · Senior Member

I have a Hammerlock joined to a rated D shackle x2. Does the job.

Dick.

BruDi · Senior Member

We have 2 hammerlocks joining extensions for our two chains. These were done by a recognised caravan repairer/maker and gave us the extra length we needed on our Vista RV Crossover. We had to get the towbar lengthened for the Prado and so the chains were then too short. All absolutely legal.

Di

EkyLea · Newbie

Hi Forum, I measured the chain on our van @ 13mm, the Hammerlock upper rating for this chain is 13mm it also comes with specs and A/S https://www.ebay.com.au/itm/2-Pack-13mm-Chain-Link-Connector-Hammerlock-Joiner-4X4-Chain-Link-Coupler/302099052395?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D20160908110712%26meid%3D33184b6e96364a77945e4c39006921bc%26pid%3D100677%26rk%3D14%26rkt%3D30%26sd%3D302195820789%26itm%3D302099052395&_trksid=p2385738.c100677.m4598

EkyLea · Newbie

Edit chain is 12mm