Gross combination mass
Encyclopedia
A Gross Combination Mass (GCM, also maximum authorised mass, MAM) is the maximum allowable total mass
of a fully loaded motor vehicle
together with all of its trailers. It is the sum of the maximum Gross Vehicle Mass
(GVM) and the Gross Trailer Masses of all of the trailers is allowed to be.
The GCM is a function of the torque
output of the engine, the capacity and ratios of the transmission
, the capacity of the driving axle
s and tyres
, and the ability of the chassis
to withstand that powertrain
torque.
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
of a fully loaded motor vehicle
Motor vehicle
A motor vehicle or road vehicle is a self-propelled wheeled vehicle that does not operate on rails, such as trains or trolleys. The vehicle propulsion is provided by an engine or motor, usually by an internal combustion engine, or an electric motor, or some combination of the two, such as hybrid...
together with all of its trailers. It is the sum of the maximum Gross Vehicle Mass
Gross vehicle mass
A Gross Vehicle Mass is the maximum allowable total mass of a fully loaded motor vehicle, consisting of the tare mass plus the load...
(GVM) and the Gross Trailer Masses of all of the trailers is allowed to be.
The GCM is a function of the torque
Torque
Torque, moment or moment of force , is the tendency of a force to rotate an object about an axis, fulcrum, or pivot. Just as a force is a push or a pull, a torque can be thought of as a twist....
output of the engine, the capacity and ratios of the transmission
Transmission (mechanics)
A machine consists of a power source and a power transmission system, which provides controlled application of the power. Merriam-Webster defines transmission as: an assembly of parts including the speed-changing gears and the propeller shaft by which the power is transmitted from an engine to a...
, the capacity of the driving axle
Axle
An axle is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to its surroundings, with the wheels rotating around the axle. In the former case, bearings or bushings are provided at the mounting points where the axle...
s and tyres
Tire
A tire or tyre is a ring-shaped covering that fits around a wheel rim to protect it and enable better vehicle performance by providing a flexible cushion that absorbs shock while keeping the wheel in close contact with the ground...
, and the ability of the chassis
Chassis
A chassis consists of an internal framework that supports a man-made object. It is analogous to an animal's skeleton. An example of a chassis is the underpart of a motor vehicle, consisting of the frame with the wheels and machinery.- Vehicles :In the case of vehicles, the term chassis means the...
to withstand that powertrain
Powertrain
In a motor vehicle, the term powertrain or powerplant refers to the group of components that generate power and deliver it to the road surface, water, or air. This includes the engine, transmission, drive shafts, differentials, and the final drive...
torque.
See also
- Aggregate Trailer Mass