GAV - Common Rigid Truck and Trailer Combinations

GAV - Common Rigid Truck and Trailer CombinationsThis combination consists of a rigid truck towing a trailer connected by a drawbar.

General access rigid truck and trailer combinations don't require a permit or notice to access road networks; these vehicles have as-of-right access to the network unless a road is signposted.

GAV Dimension Limits

Vehicle dimensions apply to all heavy vehicles. If a GAV exceeds a dimension limit, it becomes a Restricted Access Vehicle (RAV) and will require a notice or permit to access a road or network.

Dimension limits refer to the maximum size and height of a heavy vehicle. The following table summarises general dimension (size) for a rigid truck and trailer.

Width 2.5 metres
Height 4.3 metres
Length 19 metres
Rear Overhang

3.7 metres or 60% of the 'S' dimension (Wheelbase) (whichever is lesser)

 

GAV Mass Limits

The below tables provide image demonstrations of the:

  • maximum applicable mass for an axle group
  • minimum required axle spacing for the maximum axle group mass limit.   
  • maximum total combination mass limit under GML

In some cases, the rigid truck and trailer combination may need to operate at a lesser axle group mass limits (reduced mass) to comply with:

  • the maximum total combination mass limit under GML; or
  • the tow mass ratio; or
  • The heavy vehicles GCM

For more details on mass limits, refer to the General Mass Limits webpage

Note: The mass of a dog trailer or pig trailer must not be more than the towing vehicle's mass.

Rigid truck towing a dog trailer

Rigid fitted with: Illustration of heavy vehicle

Maximum Mass

GML (tonnes)

Maximum Mass CML (tonnes)

a single steer and single drive towing a dog trailer fitted with 2 single axles example image 30.0  CML does not apply to a single axle
a complying steer and single drive towing a dog trailer fitted with 2 single axles

 

30.5 CML does not apply to a single axle
a single steer and tandem drive towing a dog trailer fitted with 2 single axles

 

40.5  41.0 
a complying steer and tandem drive towing a dog trailer fitted with 2 single axles   41.0  41.5
a single steer and tandem drive towing a dog trailer fitted with a single and tandem axle groups

 

42.5  43.5 
a complying steer and tandem drive towing a dog trailer fitted with a single and tandem axle groups

 

43.0 44.0
a single steer and tandem drive towing a dog trailer fitted with 2 tandem axle groups   42.5  43.5 
a complying steer and tandem drive towing a dog trailer fitted with 2 tandem axle groups

 

43.0 44.0
non-load sharing twinsteer and tandem drive towing a dog trailer fitted with a single and tandem axle groups   42.5  43.5 
load sharing twinsteer and tandem drive towing a dog trailer fitted with a single and tandem axle groups

 

42.5 43.5
non-load sharing twinsteer and tandem drive towing a dog trailer fitted with 2 tandem axle groups   42.5  43.5 
load sharing twinsteer and tandem drive towing a dog trailer fitted with 2 tandem axle groups

 

42.5  43.5 

In the above examples, those marked with an * have been reduced or may need to be reduced to meet:

  • the maximum allowable total combination mass; or
  • 1:1 tow mass ratio.

 

Rigid truck towing a pig trailer

Note: CML does not apply to a single axle or a rigid truck towing a pig trailer
Rigid fitted with Image of heavy vehicle Maximum Mass GML (tonnes)
a single steer and single drive towing a single axle pig trailer  Rigid truck towing pig trailer 24.0
a complying steer and single drive towing a single axle pig trailer  

 

24.5
a single steer and single drive towing a tandem axle pig trailer 

 

30.0
a complying steer and single drive towing a tandem axle pig trailer

 

30.5
a single steer and tandem drive towing a single axle pig trailer 

 

31.5
a complying steer and tandem drive towing a single axle pig trailer 

 

32.0
a single steer and tandem drive towing a tandem axle pig trailer    37.5
a complying steer and tandem drive towing a tandem axle pig trailer 

 

38.0
a single steer and tandem drive towing a tri-axle pig trailer    40.5
a complying steer and tandem drive towing a tri-axle pig trailer 

 

41.0
non-load sharing twinsteer and tandem drive towing a pig trailer a single axle   35.5
load sharing twinsteer and tandem drive towing a pig trailer with a single axle

 

36.5
non-load sharing twinsteer and tandem drive towing a pig trailer a tandem axle group   41.5
load sharing twinsteer and tandem drive towing a pig trailer with a tandem axle group

 

42.5
non-load sharing twinsteer and tandem drive towing a pig trailer a tri-axle group

 

42.5
load sharing twinsteer and tandem drive towing a pig trailer with a tri-axle axle group   42.5

In the above examples, those marked with an * have been reduced or may need to be reduced to meet:

  • the maximum allowable total combination mass;
  • or 1:1 tow mass ratio.

 

Rigid truck towing a tag trailer

Rigid fitted with Image of heavy vehicle Max Mass GML (tonnes) Maximum Mass CML (tonnes)
a single steer and single drive towing a single axle tag trailer

rigid truck towing tag trailer

24.0 CML does not apply to a single axle,
a complying steer and single drive towing a single axle tag trailer   24.5 CML does not apply to a single axle,
a single steer and single drive towing a tandem axle tag trailer   24.5 CML does not apply to a single axle,
a complying steer and single drive towing a tandem axle tag trailer

 

31.0 CML does not apply to a single axle,
a single steer and single drive towing a tri-axle axle tag trailer

 

24.5 CML does not apply to a single axle,
a complying steer and single drive towing a tri-axle axle tag trailer

 

31.0 CML does not apply to a single axle,
a Single steer and tandem drive towing a single axle tag trailer

 

31.5 32.0t
a complying steer and tandem drive towing a single axle tag trailer

 

32.0 32.5t
a Single steer and tandem drive towing a tandem axle tag trailer  

 

39.0 40.0
a complying steer and tandem drive towing a tandem axle tag trailer   39.5 40.5
a Single steer and tandem drive towing a tri-axle tag trailer

 

42.5 44.0
a complying steer and tandem drive towing a tri-axle tag trailer   43.0 44.5
non-load sharing twinsteer and tandem drive towing a single axle tag trailer

 

35.5 36.0
a complying steer and tandem drive towing a single axle tag trailer

 

36.5 37.0
non-load sharing twinsteer and tandem drive towing a tandem axle tag trailer   42.5 43.5
a complying steer and tandem drive towing a tandem axle tag trailer

 

42.5 43.5
non-load sharing twinsteer and tandem drive towing a tri-axle tag trailer   42.5 44.5
a complying steer and tandem drive towing a tandem axle tag trailer

 

42.5 44.5

In the above examples, those marked with an * have been reduced or may need to be reduced to meet:

  • the maximum allowable total combination mass; or
  • 1:1 tow mass ratio.
Note: The mass of a dog trailer or pig trailer must not be more than the towing vehicle's mass.

 

Definitions

Trailer type

Relevant position of axle/axle group

 

Axle spacing

The spacing between axle groups determines the maximum allowable mass over those axle groups.

Figure 1 shows an example of the axle spacing requirements and mass limits for a rigid truck and dog trailer. There are six checks which all must comply with axle spacings mass limits general table. The spacing between axle groups determines the maximum allowable mass over those axle groups.

Rigid truck and trailer axle spacing

Figure 1 - axle spacing for a four-axle rigid combination

Heavy Vehicle (Mass, Dimension and Loading) National Regulation Schedule 1

Concessional mass limits (CML)

 

Concessional mass limits are mass exceptions that apply as an exception to the general mass limits. CML applies to certain heavy vehicles and the operator of the CML heavy vehicle must hold NHVAS Mass Management Accreditation and the vehicle must be nominated.

Heavy Vehicle (Mass, Dimension and Loading) National Regulation Schedule 2

Complying steer vehicle is otherwise known as FUPS

 

Allowable steer axle mass increase on all Heavy Vehicles greater than 15tonnes.Compliant vehicles may operate with up to an additional 0.5tonnes on the front steer axle (single only). The allowable GVM or GCM can be increased by the additional mass carried on the front steer only.

Where no additional mass is carried on the front steer axle, no GVM or GCM increase is allowed.

FUPS is conditional on the manufacture's ratings for the axles, GVM & GCM

Heavy Vehicle (Mass, Dimension and Loading) National Definitions

Dog trailer

A typical dog trailer has an axle or axle group at the front that is steered by connection to a towing vehicle by a drawbar and an axle or axle group at the rear of its load carrying surface.

Heavy Vehicle (Vehicle Standards) National Regulation Section 4

Drawbar

That part of a trailer (other than a semitrailer) that connects the trailer body to a coupling for towing purposes.

Drawbar diagram

Heavy Vehicle (Vehicle Standards) National Regulation  

Gross Combination Mass (GCM)

  • the total maximum loaded mass of the motor vehicle and any
  • vehicles it may tow in a combination

Heavy vehicle National Law (HVNL) Definitions

Gross Vehicle Mass (GVM)

The maximum loaded mass the vehicle

Heavy vehicle National Law (HVNL) Definitions

General Mass Limits (GML)

The heavy vehicle general axle mass limits prescribed in the HVNL that apply to public roads in Australia unless otherwise limited by load restriction signs. 

Heavy Vehicle (Mass, Dimension and Loading) National Regulation Schedule 1

Higher mass limits (HML)

A mass exception under the HVNL which allows higher mass limits on approved routes for particular vehicles or vehicle combinations dependent on other conditions being met (e.g. IAP and/or road friendly suspension may need to be fitted to the vehicle).

Heavy Vehicle (Mass, Dimension and Loading) National Regulation Schedule 5

load-sharing suspension system (of an axle group)

means a suspension system:

  1. (a) built to divide the load between the tyres on the group so no tyre carries a mass more than 10% above the mass it would carry if the load were divided equally; and
  2. (b) with effective damping characteristics on all axles of the group

Heavy Vehicle (Mass, Dimension and Loading) National Regulation

Pig trailer

A trailer that has:

  • 1 axle group or a single axle near the middle of its load carrying surface; and
  • connected to the towing vehicle by a drawbar

Heavy vehicle National Law (HVNL) Definitions

Rigid Truck

A rigid motor vehicle built mainly as a load carrying vehicle.

Heavy vehicle National Law (HVNL) Definitions

Rear overhang

 

 

Semitrailer

A trailer that has:

  • one axle group or a single axle towards the rear; and
  • a means of attachment to a prime mover that results in some of the mass of the trailer’s load being imposed on the prime mover.

 

tag trailer

A typical tag trailer is a type of semitrailer that has a single axle or axle group towards the rear of its load carrying surface and is connected to the towing vehicle by a rigid drawbar.

 

Twinsteer

a hauling that is fitted with a tandem steering axle group.  

The tandem steer axle group is equipped with single tyres to both axles and connected to the same steering column. The axles are spaced at least 1m apart but no more than 2m apart. 

Figure 1 demonstrates the minimum axle spacing requirements of a prime mover fitted with a twinsteer axle group, required to obtain the maximum GML as 11t for load sharing .

Rigid twinsteer max mass limit spacing

Heavy vehicle National Law (HVNL) Definitions

 

Total combination mass

The maximum allowable mass limit for a heavy or combination.

 

Tow mass ratio

The ratio of the mass of the rigid vehicle to the combined mass of the towed trailer, when all are connected as part of a combination.

 

 

Note: Combinations operating at Higher Mass Limits (HML) are considered a Restricted Access Vehicle (RAV) and must comply with the relevant state notice or permit conditions.