Thread: Army trailer chains and Perentie attachment points

Originally Posted by bacicat

.....url]https://www.vicroads.vic.gov.au/~/media/files/documents/safety-and-road-rules/vsi24.ashx?la=en[/url]

.....

That document is 16 years old. Is there a more recent one?

Originally Posted by rathgar

But when you do start searching for shackles it doesnt take long to **** documents by state authorities addressing the issue. From Queensland.

www.tmr.qld.gov.au/~/media/Safety/.../Safe_towing_guide.pdf

Safety Chain Connections (Shackles)
TMR requires that ?D? Shackles, used to connect a trailer safety chain(s) to the towing vehicle, must have
strength that is compatible with the safety chain (fit for purpose). This can be ensured in a couple of ways:
1. Use of ?D? Shackles that comply with AS 2741-2002 ?Shackles? and having the appropriate
markings is one way. TMR recommends this method.
2. Another way of ensuring that the ?D? Shackle used is of appropriate strength is to select a ?D?
Shackle of reputed brand (for example, a towbar manufacturer) so the part has its brand
name/model permanently marked on it.
?D? Shackles that do not have any markings make it difficult to identify there source and strength and may
raise questions during any roadside audit by enforcement officers.

Yep. This appeared on a caravaners forum over a year ago. It is a guide. For Queensland.
It advises rated shackles be used but does not state they must be used.
For best practice, it is advised rated shackles be used. To follow best practice, I always loop rated shackles on my pigtails.

Originally Posted by rathgar

That document is 16 years old. Is there a more recent one?

No. That is the current one as published on the Vicroads website.

Originally Posted by Mick_Marsh

Marked in accordance with the relevant Australian standard.
Doesn't mention anything about being rated.
What type of markings are required? What is the relevant Australian standard? What does that standard require?

The document states the standard. Without going to my local library and accessing the standard I can't read it.
Life is too short.

Originally Posted by Mick_Marsh

...... always loop rated shackles on my pigtails.

And at about $6 each that is money well spent.

Here's another interesting fact about chains.
Rated chains lose their rating when you modify them. Heating them up is enough to make their rating null and void.
How do you attach the chain to the trailer? Usually by welding it to the drawbar. This process then renders the rating of the chain null and void.

also

When attaching the trailer to the vehicle, the whole system must be considered. The system must conform to the ADRs applicable to the vehicle at the time of manufacture.

Originally Posted by Mick_Marsh

Here's another interesting fact about chains.
Rated chains lose their rating when you modify them. Heating them up is enough to make their rating null and void.
How do you attach the chain to the trailer? Usually by welding it to the drawbar. This process then renders the rating of the chain null and void........

The documents I quoted only warn about this for "grade T" I am not a chain expert but I assume that means there are alternatives that are suitable for welding.


One of my trailers is fitted with a rated shackle at each end. But I'm sure I previously found a document saying that this was not legal. Can't find it now.

VSB1 states how chains should be attached to the drawbar, once you get to an ATM of 2.5T I think it is the chain must NOT be welded so think hammerlock or permanent bolted connection.

The big argument is as follows.

VSB / Australian standards state that the breaking strain of the safety must exceed the ATM.
"Rated Rigging Equipment" has an applied safety factor. So a 2T WLL rated shackle actually has a breaking strain of 10T.

If your trailer is 2T ATM, you need chain and shackle capable of 2T breaking strain, which would be a "rated shackle" of 400kg.

An aluminium climbing karabiner would fulfil the breaking strain requirements of the legislation... but to keep your head above board throwing on a rated bow shackle that fits your chain links (even if the rating on the shackle is less than ATM) you will be less likely to come acropper with a zealous enforcement officer...

The take home message is a "rated bow shackle" with 8mm pin diameter has a WLL of 500kg (ie breaking strain 2.5T) this covers all small non braked trailers and a lot of braked ones too. You can fit an 8mm pin through most chains/links/attachments.

With regards to pigtails, in VSB1 they are specifically mentioned as being NOT suitable for vehicle attachment.

S