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