Heavy Vehicle (Vehicle Standards) National Regulation (NSW)

The tow coupling overhang of a heavy motor vehicle, other than a prime mover, used in a road train must not be more than the greater of—

30% of the distance from the centre-line of the front axle to the centre of the axle group, or centre-line of the single axle, at the rear of the vehicle; and

2.7m.

The tow coupling overhang of a semitrailer, or a dog trailer consisting of a semitrailer and converter dolly, used in a road train must not be more than 30% of the distance from the relevant point of articulation for the trailer to the centre of the axle group, or centre-line of the single axle, at the rear of the trailer.

The tow coupling overhang of another dog trailer used in a road train must not be more than 30% of the distance from the centre of the front axle group, or centre-line of the single axle, at the front of the vehicle, to the centre of the axle group, or centre-line of the single axle, at the rear of the vehicle.

For subsections (1) to (3), a distance between 2 parallel lines must be measured at right angles between the lines.

Example—

For the purposes of deciding whether a heavy motor vehicle used in a road train complies with subsection (1), the distance between the centre-line of the vehicle’s front axle and the centre of the axle group, or the centre-line of the single axle, at the rear of the vehicle (both of which are vertical lines) must be measured at right angles.

In this section—

relevant point of articulation, in relation to a heavy trailer used in a road train, means the relevant point of articulation for the heavy trailer having regard to how the road train is configured, which may be any of the following—

the vertical axis of a kingpin used with a fifth wheel coupling;

the vertical axis of rotation of a fifth wheel coupling;

the vertical axis of rotation of a turntable;

for a heavy trailer that is a dog trailer, the vertical axis of rotation of the front axle group or axle of the trailer;

for a heavy trailer that is a semitrailer, the imaginary vertical line passing through the pivot point for a coupling fitted to the semitrailer.

Examples—

Point of articulation—fifth wheel coupling on a converter dolly (forming the front axle group of a dog trailer)

Point of articulation—fifth wheel on a prime mover

Point of articulation—kingpin fitted to a fifth wheel coupling

tow coupling overhang, of a heavy vehicle, means the distance from the centre of the axle group, or the centre-line of the single axle, at the rear of the vehicle to the imaginary vertical line passing through the pivot point of the coupling near the rear of the vehicle.