Basic Vehicle Definitions

 

Turning Circle

Bumper to Bumper clearance needed to make a U Turn. An important number when considering that in a high risk environment – driving an armored vehicle with a high center of gravity the distance required to turn the vehicle around must be known before the driver has to turn the vehicle around during an attack scenario.

Center of Gravity

The point on the vehicle that where all the weight is balanced. It is measured from the ground to a point in the vehicle height and width. It is the balance point of the car, all forces acting on a vehicle act through the CG of that vehicle.

Height of the center of gravity

The height of the CG relative to the wheelbase determines load transfer between front and rear. The car’s momentum acts at its center of gravity to tilt the car forward or backward, respectively during braking and acceleration. A high CG and stop and go traffic has been known to cause motion sickness.

Weight above center of gravity

The weight above the CG determines the vehicles tendency to roll over. In an armored vehicle, most of the additional weight is in the windshield, which is above the CG of the vehicle, hence easier to create a rollover scenario.

The Statics Stability Factor (SSF)

The SSF is a number the US safety agency, the National Highway Traffic Safety Administration, determines a vehicles rollover probability; it is the vehicles at-rest calculation of its rollover resistance. The number is based on the vehicles geometric properties. SSF is a measure of how top-heavy a vehicle is.

Tire Pressure vs. Payload

SUV’S are much more sensitive to loading and tire pressure. Consult the vehicle manual for correct tire pressure and for the payload capacity. You will more than likely find that the tire pressure will vary in accordance to the load being carried.     The payload is defined as- the combined, maximum allowable weight of cargo, occupants that the vehicle is designed to carry.