The following definitions apply the principle of stability of Powered Industrial Trucks Center of gravity is the point on an object at which all of the object's weight is concentrated. For symmetrical loads, the center of gravity is at the middle of the load. Counterweight is the weight that is built into the truck's basic structure and is used to offset the load's weight and to maximize the vehicle's resistance to tipping over. Fulcrum is the truck' s axis of rotation when it tips over. Lateral stability is a truck's resistance to overturning sideways.
Line of action is an imaginary vertical line through an object's center of gravity.
Longitudinal stability is the truck's resistance to overturning forward or rearward. In the case of a powered industrial truck, the distance is measured from the point at which the truck will tip over to the object's line of action. The distance is always measured perpendicular to the line of action. Track is the distance between the wheels on the same axle of the truck. Wheelbase is the distance between the centerline of the vehicle's front and rear wheels.