Drawbar to be securely attached to a ‘substantial portion’ of the trailer.  Longitudinal tension and compression (Newtons) 1.5 x 9.81 x ATM (kg).  That would suggest to me that it needs to be able to withstand the towing vehicle accelerating at 1.5 gravities.  Having owned a ZZR1100, and knowing that it was only JUST able to reach 1G of acceleration, I know that that’s quite a bit of force 

Transverse thrust, and vertical tension/compression is (N) 0.5 x 9.81 x ATM (kg).  Tranverse thrust, what’s that?  Vertical tension/compression? that’d be up and down on the towbar as you go over bumps?

Well, basically what those two are saying, is the drawbar needs to be REALLY WELL ATTACHED..    I’ll likely have mine very securely welded below the floor frame and front and back (and any other cross-braces I put in the floor..)

Chains.. Well, under 2.5 tonne ATM, must have one safety chain complying with AS 4177.4-1994 or AS 4177.4-2004-Part4  The attachment point for the chain should not come into contact with the road when the trailer is disconnected.   ‘Safety chains, which ave the mechanical T grade property, are not suitable for welding’.  Do we HAVE to weld? Or is a shackle between trailer and chain ok?  Find out!

Coupling – Must have  quick release coupling which is designed to be used without tools.  It must be positive locking with provision for a second independant type.  Coupling to be mounted so that the height of the center of the body of the coupling is 350-420mm above the ground when loaded.   Hmm, check the height of my motorcycle’s tow-ball!.  Coupling to be marked in accordance with ADR62/01 and ADR62/02.  This is:

• The manufacturers name or trademark.
• The mark ‘50’ (50mm ball)
• Maximum rating for the coupling (750kg)
• a code to indicated serial, batch, production date, or similar
• ‘DO NOT WELD’, if made from non-weldable material
• ‘WELD ONLY’ if the coupling is to be attached by welding only.