A guide to the most common trailer terms
Buying a trailer for the first time can be a challenging experience, mainly because the specific terminology is not known. This is a guide with the most common terms.
Aggregate trailer mass (ATM) refers to the total weight of the trailer, composed of the weight of the trailer that is not coupled to a towing vehicle and the total weight of the load. Otherwise, the gross trailer mass (GTM) is the total weight of a fully loaded trailer, which is coupled to a tow vehicle. This means that GTM will always be less than ATM because part of the weight of the towed vehicle is transferred to the tow vehicle.
Coupling It is the connection between the trailer and the towing vehicle. There are many types of couplings, depending on the weight of the load to be towed and the conditions of the trailer.
Gross Combined Mass (GCM) As the name implies it is the maximum combined weight of a vehicle, the passengers, the weight of the trailer and the weight of the load. The maximum allowed rate is set by the vehicle manufacturer. Also known by the following terms: Gross Combined Weight Rating (GCWR), Gross Train Weight (GTW), or Gross Combined Weight (GCW).
Gross vehicle mass (GVM) is the maximum weight of a vehicle, including the vehicle’s chassis, body and engine, all passengers and cargo. It is obvious that the weight of the trailer is not included in the GVM.
Single axle trailer It has an attached axle, with two connected wheels. Specifically for this type is that it can drag a certain load weight. On the other hand, Tandem Axle Trailer has two axles. Total number of wheels is 4. More wheels mean more stability, making these trailers great for pulling heavier loads. It is also known as a double shaft or double shaft.
Safety chains They are attached to the trailer, allowing it to remain connected to the towing vehicle in the event of its disconnection. They should be checked every time a trailer is towed.
Tare mass refers to the empty weight of a trailer. This weight is usually stamped on the trailer itself, by the manufacturer.
FOR Useful load is the maximum allowable weight of the load for which a trailer is designed. It is the difference between your Tara Mass and your ATM.
CAME is a vehicle information number, containing 17 characters. A trailer is identified with that unique number. Some states in Australia require the VIN to be stamped on the trailer.
Weight distribution system is a system that increases the towing capacity of a trailer, improving handling and braking. The system is located around the couplings, including additional equipment.