Length of Safety Chains.

Haji-Baba · Senior Member

Length of Safety Chains.

spinjohn · Member

Jeff, the normal way is to just cross the chains under the hitch and I have them as short as possible but still enough length to not become tight while on full lock.

This way if you should by any chance become unhitched they should catch the hitch and stop it nose diving into the road surface.

New Wanderers · Veteran Member

I think I'd rather have the safety chains a little long rather than little short. Thanks Jeff for confirming the correct way to have the chains, I once hired trailer and I was about to cross the chains and was told not to, I thought its your trailer that i'm trying to protect and I'll connect it your way. Recently we hired a caravan and they confirmed the correct way is to cross them just incase the van does come unhitched to help prevent nose of the caravan coming in contact with the road and it turning pretty ugly.

Olley46 · Guru

I have done a mok de tachment with my van and 4wd ,there is no way in the world that I can put my chains to catch the a frame if it comes off to stopping it from hitting the ground, the reason is when your van de hitches as the a frame is falling to the ground ,so are the chains that are on the a frame, IF you shorten the chains to catch the a frame you have bugger all turning angle ,so in actual fact it cant be done on my vehicle, maybe it will work on a vehicle with higher towing height.i still cross my chains I guess it's habbit.

Lance C

-- Edited by Olley46 on Monday 2nd of June 2014 08:10:19 PM

ozjohn · Guru

Lance the same would be true for most vanners especially those using heavy duty WDH's where long chain lengths are required.
But for those who have vans registered in NSW or WA there is no choice as it's a legal requirement. This may also apply to other states, but I've never been able to find any specific regulation.
Even though I'm in VIC I still cross chains as I was taught to do as a young bloke and had hair on by head and not of my face. biggrin
Ozjohn.

spinjohn · Member

All, lets be realistic, it would be a bonus if after your van becoming detached from some failure the safety chains were set up and cradled your A frame, but they are I believe intended to stop your van becoming totally detached and careering across into oncoming traffic or pedestrians etc.

Yes there probably is going to be some rear damage to the tug and hitch, but not any where near as much as a loose van would cause, sustain.

Just my 2 cents worth.

Baz421 · Guru

ozjohn wrote:
Lance the same would be true for most vanners especially those using heavy duty WDH's where long chain lengths are required.

Agree John,, we have the heavy duty American Reece and no way can chains prevent aframe hitting the ground in case of ball or hitch failure.

Aus-Kiwi · Guru

In NSW chains must be crossed.. There is weight where 2 chains are required..
I've built a few car carrying trailers . The chains MUST be welded where
bind is limited.. Which I assume is near the hitching point..
The anchoring point on tow vehicle the same.
I see chains on some trailers that wouldn't hold a dog on a windy day..

Yes crossed and NOT able to hit the ground.. If there's binding ?? Then the chains are defective!!

-- Edited by Aus-Kiwi on Monday 2nd of June 2014 10:11:07 PM

PeterD · Guru

HR have safety chain extension kits. I have seen those at caravan shows and the demo display looked like they would stop the coupling hitting the ground if the van detached from the van. Download this catalogue. Then look at page 69.

Friar Park · Senior Member

The laws of two states say cross 'em so i cross 'em in all states. I refuse to make additional contributions to undeserving pollies superfund.

Friar

ozjohn · Guru

Drawbar Safety Chains

All pig trailers with rigid drawbars (with or without breakaway brakes but excluding converter dollies) and, any other trailer without breakaway brakes, must be fitted with safety chains that are marked in accordance with the relevant Australian Standard and (or cables as applicable) complying with the following:

trailers that do not exceed 2.5 tonnes ATM must have at least one safety chain complying with Australian Standard AS 4177.4-1994 or Australian Standard AS 4177.4-2004 'Caravan and light trailer towing components Part 4: Safety chains up to 3500kg capacity', or be a safety cable with a certified load capacity of the same;
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;
trailers over 3.5 tonnes ATM must have two safety chains made from steel of a minimum 800 MPa breaking stress that conforms to the mechanical properties of Grade T chain as specified in Australian Standard AS 2321-1979 'Short Link Chain for Lifting Purposes (non calibrated)' or Australian Standard AS 2321-2006 'Short Link Chain for Lifting Purposes.' Each chain must be sized such that the minimum breaking load exceeds the ATM.

Caution
Safety chains, which have the mechanical T grade property, are not suitable for welding.

(For further information, refer to ADR 62/01 clause 14)

Drawbar Safety Chain Attachment Points

Safety chain attachment points are the means by which the safety chains are attached to the drawbar. These points must be located as near as practicable to the tow coupling. Where two points of attachment are required, they must be mounted one on either side of the centreline of the drawbar.
Each safety chain attachment point must be capable of withstanding the following minimum forces without incurring either any residual deformation that would interfere or degrade the function of the assembly, or any breaks, cracks or separation of components:

Longitudinal tension and compression (N) 1.5 x 9.81 x ATM (in kg)

Vertical tension and compression (N) 0.5 x 9.81 x ATM (in kg).

(For further information, refer to ADR 62/01 clause 14)

Caution
Load levelling bars should only be used with towbars designed for load levelling. Very high forces can be generated when the vehicle and trailer combination travels through dips in the roadway. These high forces may exceed the design limits of the towbar and or its mountings.

Caution
Drawbar safety chain attachment points should not come into contact with the road surface when the trailer is disconnected.

Haji-Baba · Senior Member

Let's face a few facts lads.

The usual chains provided by the van manufacturers show no strength ratings at all. The average shackel would be suspect as well.

By the way my chains are welded to the "A" frame so I assume non high tensile.???

The majority of all trailers will hit the ground if they become detached with or with out the chains crossed.

Unhitch your trailer and check, most will hit the ground.

The biggest advantage of a W.D.H. is two fold, one, it helps to distribute loading on the tow vehicle and secondly keeps the yoke loaded onto the tow ball. Have you ever tried to detach a trailer before removing the Hitch. Impossible in most cases.

In the case of off road usage of a trailer removing the Hitch is absolutely essential to eliminate excessive strain on the tow bar and
"A" frame.

Any requirement to cross deep gullies or creek crossings will exert enough pressure on the towing components to break something.

As far as legal requirements are concerned some one show me a road safety gazetted rule that requires safetry chains to be crossed. I am in educational mode.

Ozjohn came up with a "rule" that states, Quote, "if the trailer comes adrift the attachment points must not hit the road way"
un quote.

Now that makes a lot of sense as the trailer may still stay attached and the chain anchor points won't be worn away on the road surface.

In my case my van has two chains but I could get away with one so crossing them would make no difference at all.

Just as an exercise why don't we all just go out to our vans/trailers and do a practical physical test?????

And don't forget to note the strength ratings on the chains and shackles.

I am interested.

Have fun Haji-Baba.

rockylizard · Guru

Haji-Baba wrote:
Let's face a few facts lads.

The usual chains provided by the van manufacturers show no strength ratings at all. ~~~ The chains on my van are STAMPED PWB 4177-35 (See Photo below, and attached website for rating)

As far as legal requirements are concerned some one show me a road safety gazetted rule that requires safety chains to be crossed. I am in educational mode.

Ozjohn came up with a "rule" that states, Quote, "if the trailer comes adrift the attachment points must not hit the road way"
un quote.

Now that makes a lot of sense as the trailer may still stay attached and the chain anchor points won't be worn away on the road surface.

In my case my van has two chains but I could get away with one so crossing them would make no difference at all. Perhaps ????
Quoting Ozjohn's Post -
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;
trailers over 3.5 tonnes ATM must have two safety chains made from steel of a minimum 800 MPa breaking stress that conforms to the mechanical properties of Grade T chain as specified in Australian Standard AS 2321-1979 'Short Link Chain for Lifting Purposes (non calibrated)' or Australian Standard AS 2321-2006 'Short Link Chain for Lifting Purposes.' Each chain must be sized such that the minimum breaking load exceeds the ATM.

Just as an exercise why don't we all just go out to our vans/trailers and do a practical physical test?????

And don't forget to note the strength ratings on the chains and shackles. The chains on my van are STAMPED PWB 4177-35 (See Photo below, and attached website for rating)

I am interested.

Have fun Haji-Baba.

Gday...

The chains on my van are stamped PWB 4177-35 on EACH link.

This is snipped from website - http://www.pwbanchor.com.au/chain-fittings/pwb-chain/trailer-safety/trailer-safety-chain-galvanised-/product-detail.aspx

cheers - John

Haji-Baba · Senior Member

Hi! R.L. take your point re; chain sizes and markings. My chains show nothing but the shackles are rarted.

Ozjohn stated that the attachment point for chains had to be, as I read his notes, on the side of the "A" frame or draw bar to prevent damage from the road way. Very good idea. I think that is the usual method of fixing "safety chains".

Peter D introduced a H.R. document that shows a fitting to keep the chains elevated, a very good idea, and easily fitted or adapted to suit.

But if you used the H.R. attachment as per catalogue I am of the opinion that it would preclude crossing chains.

Anyway my initial post has partially been answered by Peter D. and I already have my chains elevated by my own devices.

Have fun Haji-Baba