Commonwealth Consolidated Regulations

INTERSTATE ROAD TRANSPORT REGULATIONS 1986 - REG 12B

         (1)   For the purposes of paragraphs 12B (2) (a) and 13 (1) (aa) of the Act, the maximum permitted gross mass on an axle group of a vehicle is the least of:

                (a)    the sum of the mass limits on the tyres on the axle group calculated in accordance with subregulation (2); and

               (b)    the gross axle load rating specified by the manufacturer of the axle group in respect of that axle group; and

                (c)    for an axle group of a kind mentioned in an item in Schedule 4:

                          (i)    if it does not have road friendly suspension -- the axle load limit mentioned in column 3 of the item; and

                         (ii)    if it has road friendly suspension -- the axle load limit mentioned in column 5 of the item.

Note    Regulation 12BAA deals with the maximum permitted gross mass for a single steer axle for vehicles with a gross vehicle mass of 15 tonnes or more.

         (2)   For the purposes of paragraph (1) (a), the mass limit on a tyre is the greatest load capacity determined for the tyre by the manufacturer at a cold inflation pressure that does not exceed:

                (a)    for a radial ply tyre -- 825 kilopascals; or

               (b)    for any other tyre -- 700 kilopascals.

         (3)   For the purposes of paragraph (1) (c), if an axle group of a kind specified in Schedule 4 includes a retractable axle, the axle load limit for that group must be determined as if that axle did not exist, unless subregulation (4) applies.

         (4)   A retractable axle is part of an axle group for the purposes of Schedule 4 if, when the mass on the group exceeds:

                (a)    in the case of a tandem axle group -- 6 tonnes; or

               (b)    in the case of a triaxle group -- 11 tonnes;

the tyres on the axle touch the ground and there is load sharing on each axle (including the retractable axle) and tyre in the group.