Shackles ain’t shackles: The legalities on different shackles for towing and their ratings

ByUnsealed 4X4August 24, 2020
Shackles ain’t shackles: The legalities on different shackles for towing and their ratings

Words and photos by Tim Scott

While all shackles are not created equal, they’re not all yellow either – what difference does it make? And do my caravan or camper shackles have to be yellow?

You’d be forgiven for thinking the sky was about to fall in. Your shackles aren’t yellow and you’re being called out for it – ‘it’s illegal to not have yellow shackles between your car and trailer!’ you’ll hear cried from soapboxes across social media.

Well, rest assured, it’s not mandatory to have yellow shackles. In fact, it’s become a bit of a social media tease-fest and the mischievous trolls love a good rev-up. Still, some people have adopted this mantra, and the yellow shackle crew accept no alternative. You have alternatives; some are blue, and some are red, and some are just plain old galvanised.

The only opinion to trust in this discussion is the official one, and that’s the Australian Standard, excitingly called AS 2741-2002. However, you could be forgiven for still scratching your head, because it’s slightly vague, in that the official discussion paper about shackles relates to lifting not towing. So it’s not entirely useful unless you’re looking to attack Gunshot Creek up The Cape, hole first, in which case you will be lifting your camper or caravan.

Bow Shackle (3)

So that’s the overarching legislation, such as it is, and as you can imagine it might be open to interpretation by whoever is asking the questions about your shackles as to whether you’ve broken any rules.

Circular 0-1-3 from the Department of Infrastructure gives this statement below in its attempt to give some clarity about shackle use, under the heading: Safety chain connection devices for road trailers which are up to 3.5 tonnes (3500kg) Aggregate Trailer Mass (ATM)

We quote: “Since there is no legal obligation to comply with this guidance material if an individual or a company chooses not to follow this material, it is the responsibility of the person or the company to demonstrate to state or territory road authorities that a particular safety chain connection device is appropriate for the combination vehicle.”

No mention about colour. Although we do learn of two shackle types: Bow and D shackles, which also come up for examination in their use for caravans. These terms merely relate to the shape of the bent component, as in, one shackle is bow-shaped and one is D-shaped. The only technical difference is that the bow shackle gives what’s termed greater angular displacement (click here). As in, the bow shape allows more freedom of movement for your chain and shackle.

The official definition:

Bow shackle: O-shaped body that is enclosed at the end by either a threaded clevis or cotter pin and used to connect a safety chain between a road motor vehicle and road trailer.
D-shackle: U-shaped body that is enclosed at the end by either a threaded clevis or cotter pin and used to connect a safety chain between a road motor vehicle and road trailer.

As we keep banging on about in this area of caravan technicalities, the vital links are all weight-related, and all you need to know about a shackle should be stamped upon it. Things like its working load limit, or WLL. Also, your shackle must carry other stamps – the manufacturer’s name or trademark – and have a break limit that is 1.5 times the ATM of your trailer. For example, if your ATM is 750kg, the break load limit rating must be 1125kg and with an ATM of 1000kg, the shackle must have a break load limit of 1500kg. Generally, the break load limit of a rated shackle will be six times greater than its WLL. The shackle should also have identification marking in order to correlate shackle to test certificate.

The shackle will carry its diameter in mm and a grade stamp, for instance, 10mm and be graded S, and, say, a 6mm will be graded M, and have a lesser WLL than the S grade. The shackle’s pin (sometimes painted yellow) must have a greater diameter than the bow, or D section. Stainless steel is not recommended for shackle construction. It is quoted in most interpretations of the official policy that since the loading on these shackles is different when used to attach a safety chain to a road vehicle, as compared to when used in a lifting application, a road trailer may be towed that is heavier than the shackle’s WLL.

Caravan shackle selection chart

Essentially, popping out and buying a shackle without checking any of these stamps are on it, means you’re buying an unknown quantity and trusting that to secure your trailer in the event of a hitch/ball separation. Plus, it has to endure the rigours that towing exerts on components, with huge forces involved. It might do the job once, twice, but the third time might not be a charm.

There has been a recommendation in place from the Caravan Industry Association and it’s a safe bet to say that the S (or 6) graded, 10mm shackle stamped at WLL 1.25T will suffice for trailers up to 3500kg.

No one will mind you opting for over-engineered options, but remember before you arrive home with your massive shackles that they have to accommodate the chain links and the eyes on the towbar arrangement you have on your tow vehicle. The hammerlock device (also comes in yellow) can only be used to lengthen a safety chain, not replace a shackle, plus only one shackle per chain is allowed.

Bow Shackle (2)

So, no, your caravan shackles do not have to be yellow, but they do need to be rated for the job. That’s common sense, even if it’s not absolutely carved in law.

For a light reading session see the whole VSB1 via this link!