1.6. STRUCTURE AND STABILITY OF THE LIFT TRUCK 1.6. STRUCTURE AND STABILITY OF THE LIFT TRUCK To operate the lift truck safely, it is important to understand the structure and stability of the lift truck. This section will educate the operator in methods to prevent tipping-over the lift truck. STRUCTURE OF LIFT TRUCK Forklift trucks basically consist of a lifting mechanism (fork and mast) and a main body (vehicle). The front wheels act as a fulcrum and the center of gravity of the lift truck and that of the load are kept in balance. The relationship between the positions of these two centers of gravity plays a very important role for the safety of the lift truck.
CENTER OF GRAVITY OF LOAD The loads carried by forklift trucks come in various shapes from boxes to planks and long objects. To judge the stability of the lift truck, it is important to distinguish the position of the center of gravity for loads of various shapes. CENTER OF GRAVITY AND STABILITY The stability of the lift truck is determined by the position of a combined center of gravity resulting from combining the centers of gravity of the lift truck and the load. When the lift truck is carrying no load, the center of gravity of the lift truck remains unchanged.
On the other hand, when it is carrying a load, the center of gravity of the lift truck shifts to a combined center of gravity from the centers of gravity of both the lift truck and the load. The position of the center of gravity of a load changes as the mast is tilted back or forth, or it is raised or lowered. The position of the combined center of gravity also changes depending on the following factors. Size, weight, shape of load Lifting height Tilting angle of mast Inflation pressure of tires Acceleration, deceleration, turning radius Condition of road surface, angle of road Type of attachments 1-26