You may need to comply with this standard if you intend to operate a B-double or road train. You must ensure that any kingpin in your vehicle has dimensions, a D value and markings that comply with this standard. You must also ensure it is attached in accordance with this standard.
This standard sets out the attachment design forces for fifth wheel assembly and equations to determine the required D-value of components for various combinations. This standard applies to fifth wheel assemblies used with 50 mm, 75 mm and 90 mm kingpins, and associated equipment for articulated vehicle combination, used in heavy road vehicles, B-doubles and road trains, in normal use on both sealed and unsealed roads.
The specific version of this standard you need to comply with is AS 2175-1990 Articulated Vehicles - Kingpins.