Thread: Three Point Five Tons.

Hi Mogwog

I was having some issues with towing a trailer on the weekend. The trailer has an ATM of 2 tonnes and I was trying to fit the rated shackles to the D4 but couldn't get them to fit. Is their a secret method to doing this? How do you fit 3.5T shackles?

Hope you can help.

Maybe I don't have 3.5T shackles. I will have to check now.!

A dumb question maybe but do you need 3.5 ton shackles or 2 x 1.75 ton shackles?

cheers,
Terry

Attach the shackles to the rear recovery point - you may need to juggle it around a little.

Cheers,

Gordon

Originally Posted by TerryO

A dumb question maybe but do you need 3.5 ton shackles or 2 x 1.75 ton shackles?

cheers,
Terry

X2. But make sure they are rated gal bow shackles. Bullivants or any lifting equipment suppliers will stock these. I run two 2 tonne bow shackles with my van (ATM 2581kg).
Ps: My D2a does a preaty admirable job at towing our van if I don't say so myself!!
Regards
Robbo

You're not trying to lift the full weight of the trailer with the shackles, lifting is what "rated shackles" refer to.

I believe the applicable Australian Standard (AS4177.4) is lacking in not clearly stating requirement for shackles. For 3.5 tonne the chain welded to the trailer needs to be 13mm and that's for each chain. 13mm chain has a breaking load over 20 tonne! "Proof" is around half of this. Appears to be a bit of an overkill but I'll except it.

As for the shackle, unless someone can point me to a standard, ADR, state / federal road authority or legislation I would be happy with a shackle that has a material diameter equal to the chain, preferable a "rated" shackle as the material used to manufacture it is held to higher specification and tolerances.

Well that's my two cents worth.

My preference is to cross over the chains under the coupling so if it does let go the coupling / drawbar is carrier by the chains instead of hitting the road and flailing around banging into the vehicle.

Hi,

There has been a lot of debate about this on the caravan forum. The upshot seems to be that most states require a given size shackle for a van of given mass. See this thread

The clearest commentary seems to be that of QLD, who have a bulletin called "safe towing" found here

This guide defines....
Safety chain connections (shackles, pins or bolts)
A suitable shackle is where:
+the shackle is rated and complies with Australian Standard AS 2741-2002 “Shackles”
or other equivalent recognised standard; and
+the break load limit of the shackle is rated at least 1.5 times greater than the ATM of
the trailer

So it seems that you need two shackles of at least 1.5 times the ATM of the trailer (for trailers or caravans under 3.5 tonne).

Which is why the question of what size shackle fits through the eye in the tow pintle is important.

BLL if I remember correctly is 5 times the WLL.

A 1.5 tonne shackle will not fail till at least 7.5t is applied.

And SA requirements are for rated chain and rated shackles attached to rated points.