There are 5 important steps to ensuring safety is a top priority. The initial step is completing a Walk-Around Inspection to be able to insure that the unit is visually safe. After that assess if the work location is safe to use with a Worksite Assessment. The Function Test is the third step so as to determine whether or not the model is safely working. The 4th thing to consider is Proper Operation, in order to know whether or not the model is working safely. Last of all, Proper Shutdown must be checked so as to make sure the model is capable of shutting down correctly and is in a safe place.
At the center of the 5 steps and this regulation, there is a machinery that lifts heavy weights to impressive heights and stands on a triangular footprint. The main goal is to be able to keep the telehandler upright, but surely there are risks.
The telehandler's triangular base consists of the two front wheels and the rear-axle pivot point. The rear axles usually oscillates, hence the rear wheels are not considered part of the base. The telehandler remains upright as long as the equipment's center of gravity, that is defined as the point in 3 dimensions around which the machine's weight is balanced, stays oriented in the stability triangle.
When the boom is down, adding a load to the forks at that time changes the center of gravity down and forward. Lifting the load will move the center of gravity upwards and to the rear. At the same time, the stability triangle shrinks when this happens. Thus, the higher you lift a load, the less of a margin for error you have because the stability triangle lessens.
When the stability triangle is small, it leaves less room for the center of gravity to move right or left. It is this wandering action that could change the stability triangle and leave less room for the frame to remain balanced if it is not completely level. For instance, imagine the center of gravity resembling a plumb bob hanging from the boom. You can always find the center of gravity someplace on a totally vertical line between a point on the boom and the center of the ground. If the frame is not level, the center of gravity would not be oriented over the equipment's centerline. The stability triangle is continuously aligned with the equipment's centerline.