The Impact of Forklift Stability on Safe Operation and Core Control Points

Forklift stability refers to the capability of a forklift to resist longitudinal (forward and backward) and lateral (left and right) overturning during operations such as traveling, lifting, turning, loading and unloading. It serves as a core underlying indicator for safeguarding the safety of equipment, personnel, and goods. Insufficient or out-of-control stability will directly lead to major safety accidents including overturning, falling goods, and collisions. The influencing mechanisms, key factors, and control measures are elaborated as follows:

I. Core Risks and Influencing Mechanisms of Stability Failure

Most forklift overturning accidents stem from the breach of the stability critical state. The corresponding relationship between the influencing mechanisms and accident types is as follows:

Longitudinal Overturning (The Most Common Accident Type)

• Affected Scenarios: Full-load lifting, ramp operation, sudden acceleration/sudden braking, excessive forward tilting of forks
• Failure Mechanism: The longitudinal stabilizing moment (provided by the forklift's dead weight and counterweight) is less than the overturning moment generated by goods and inertia, causing the forklift to overturn around the front or rear wheel fulcrums
• Typical Consequences: Operators being thrown out, goods falling and being damaged, structural deformation of equipment

Lateral Overturning

• Affected Scenarios: Sharp turns, unilateral eccentric loading, uneven ground, side slope operation, narrow-aisle operation
• Failure Mechanism: The lateral stabilizing moment is less than the overturning moment generated by centrifugal force and eccentric load force, causing the forklift to overturn around the fulcrums of wheels on one side
• Typical Consequences: Equipment rollover, scattered goods, crushing of surrounding personnel/facilities

Combined Overturning (Superposition of High Risks)

• Affected Scenarios: Combined working conditions of full load + sharp turns + ramps + high lifting height
• Failure Mechanism: The superposition of longitudinal and lateral overturning moments leads to a sharp reduction in the stability critical value, breaking through the stability limit in an extremely short time
• Typical Consequences: Major casualties, equipment scrapping, paralysis of workshop operation order

II. Key Parameters and Factors Affecting Forklift Stability

1. Inherent Equipment Parameters (Defined ex-factory, not to be altered arbitrarily)

2. Operating Condition Parameters (Dynamically controllable, key focus of on-site safety control)

• Lifting Height: The higher the lifting height, the higher the center of gravity of goods, the smaller the stabilizing moment, and the sharp decline of both longitudinal and lateral stability. Strict speed and load limits must be imposed during high-position operations.
• Traveling Speed: The faster the speed, the larger the inertia/centrifugal force. Overspeeding is the main inducement of stability failure under working conditions such as sharp turns, ramps, and full load.
• Mast Tilt Angle: Excessive forward tilt angle is prone to shift the center of gravity of goods forward, increasing the risk of longitudinal overturning. Adjusting the tilt angle during traveling is strictly prohibited; it must be done when the forklift is stationary.
• Ground Conditions: Soft, uneven, or slippery ground will lead to uneven wheel contact with the ground and reduce the stability angle. Before operation, confirm that the ground is firm and flat, and the slope conforms to the climbing capacity of the equipment.

3. Human Operational Factors (Most prone to out-of-control, requiring constraint through training and systems)

• Illegal operations such as sudden acceleration, sudden braking, sharp turns, unilateral fork picking of goods, parking/gear shifting on ramps will break through the stability critical value in an instant.
• Operators failing to fasten seat belts in accordance with regulations and failing to observe the surrounding environment will aggravate the consequences of accidents.

III. The Full-process Impact of Stability on Safe Operation

1.Before Operation: Stability parameters determine the operation boundaries (such as rated load, maximum lifting height, aisle width, ramp slope). It is necessary to check the matching degree between equipment parameters and operating conditions in advance.

2.During Operation: Stability is a dynamic balance process. Any abnormal change in parameters (such as load, height, speed, tilt angle) will affect the balance state. Real-time monitoring is required to avoid critical operations.

3.After Operation: Stability testing is a core item of equipment maintenance (such as braking system, steering system, counterweight, mast structure). Regular testing can prevent stability failure.

IV. Core Measures to Improve Forklift Stability and Ensure Safe Operation

Equipment Level

• Select forklifts suitable for the working conditions (e.g., narrow-aisle forklifts need optimized wheelbase and track width; heavy-duty forklifts need increased counterweight).
• Modification of structures affecting stability such as counterweights, forks, and masts is strictly prohibited; stability indicators must be tested regularly.

Operation Level

• Strictly implement the load curve; reduce the load when overloading or exceeding the load center distance; the higher the lifting height, the slower the traveling speed.
• Ramp Operation: When going uphill, tilt the forks forward and face the goods towards the top of the ramp; when going downhill, tilt the forks backward and travel at low speed; gear shifting/parking on ramps is strictly prohibited.
• Decelerate in advance when turning to avoid unilateral eccentric loading; high-speed traveling on uneven ground is strictly prohibited.

Personnel Level

• Operators must hold valid certificates to take up posts and receive safety training on stability (such as overturning risk identification and emergency disposal).
• Must fasten seat belts during operation to prevent being thrown out in case of overturning.