Getting ready for HVNL mass changes

By: Andrew Hobbs

A series of NHVR factsheets will help operators prepare for law changes set to come into effect on July 1

Getting ready for HVNL mass changes
Laws governing trailers such as this one of Hopper Trailers are set to change.


Changes to the Heavy Vehicle National Law (HVNL) and its associated regulations will see the maximum weight of some heavy vehicle combinations lift to 46.5 tonnes from July 1, up four tonnes from the current mass limit.

The National Heavy Vehicle Regulator (NVHR) has released a series of fact sheets about what the law changes in a bid to help heavy vehicle operators prepare for the start of the new system.

NVHR CEO Sal Petroccitto says the changes will help provide more flexibility for operators of twin steer tri-axle semitrailer combinations.

Under the new laws, the sum of all axle groups on such a truck must not exceed the new 46.5 tonne limit, with a trailer tri-axle group limited to 20t, a tandem drive axle group to 16.5t and a twinsteer axle group limited to 11t when fitted with a load-sharing suspension system.

However, the NHVR notes, some combinations with a twinsteer prime mover and tri-axle group semitrailer may be eligible for increased mass limits under mass exceptions provided by concessional mass limits or higher mass limits applicable in different states.

Further information on the new mass limits for twinsteer prime movers is available here.

Another change will require heavy vehicles to operate under a maximum towed mass ratio of 1:1 when using tag trailers, a type of semitrailer which is connected to the towing vehicle by a rigid drawbar and which has a single axle or axle group towards the end of its load carrying surface.

This means that when in combination, the operating axle mass of a tag trailer must not be more than the total axle mass of the towing vehicle or the lowest rated component in the combination.

These requirements also apply to dog and pig trailers, but not to other types of semitrailer.

Another fact sheet summarises some of the minor changes to the Heavy Vehicle Safety Standards which will come into effect from July 1.

The NHVR says the changes are "relatively minor", mainly aligning new and in-service safety standards including allowing warning signs on long vehicles and road trains to be made from flexible material and requiring a manual condensate drain valve be fitted alongside automatic condensate drain valves.

They will all be introduced alongside a new national heavy vehicle plate to be issued in New South Wales, Queensland, South Australia, Tasmania and the Australian Capital Territory from July 1 – with Victoria to join the scheme in October.


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