Definitions

In this Guide you will find a wealth of technical information, handy hints and advice, which, when put into practice, will help you to tow your Recreational Vehicle with a greater degree of confidence and safety. Towing any type of trailer involves more than attaching a towbar to your vehicle and hitching up. It adds another dimension to your driving and there are a number of considerations you should take into account.

These include:

  • the towing capacity of your vehicle;
  • the type of tow bar you should fit to your vehicle and the maximum load capacity of the coupling;
  • the maximum capacity of the trailer when fully loaded to the Aggregate Trailer Mass (ATM), specified by the trailer manufacturer, must not exceed the tow vehicle manufacturer’s specified towing capacity;
  • the ATM must be specified on the trailer’s Vehicle (VIN) Plate;
  • the type of trailer you are towing and whether it complies with all the regulations governing trailers in Australia;
  • the type of equipment you may need to fit to increase the trailer’s stability when being towed;
  • whether your trailer is correctly loaded;
  • the ways in which towing can affect your driving;
  • the safety checks you should make prior to and during your trip; and
  • the type of insurance most suitable for your caravan or trailer.

 

GVM

(Gross Vehicle Mass)

The GVM is the maximum allowable total mass of
a fully loaded motor vehicle, consisting of the tare
mass (mass of the vehicle) plus the load (including
passengers).

 

Tare Mass

The unladen weight of the complete new trailer as
delivered (including any options fitted).

 

Tow Ball Mass

The weight imposed on the tow vehicle’s tow ball
by the coupling.

 

ATM

(Aggregate Trailer Mass)

The total laden weight of a trailer, which includes
the tow ball mass and whatever you add as payload
(e.g.. water, gas, luggage). The ATM is specified by
the trailer manufacturer and must not be exceeded.

 

Payload

The allowable load carrying capacity or ‘payload’
is worked out by deducting the “Tare Mass” from
the “ATM”. It must not be exceeded under any
circumstances. Safety, insurance & warranty may
be affected if the specified payload is exceeded.

 

GTM

(Gross Trailer Mass)

The total permissible mass which includes whatever
you add as payload (e.g.. water, gas and luggage)
that can be supported by the wheels of a trailer. This
does not include the mass supported by the tow ball.

 

GCM

(Gross Combination Mass)

GCM is the rating provided by the manufacturer
of the tow vehicle. The maximum laden mass of a
motor vehicle plus the maximum laden weight of an
attached trailer is not permitted to exceed the GCM
rating.