Stability Assurance Plan for Forklift Operations on Slopes of Different Gradients (Classified Operation Standards + Risk Control)
Forklift operations on slopes are high-risk scenarios for stability accidents, with the core risks being longitudinal tipping (caused by center-of-gravity shift when ascending or descending slopes) and lateral tipping (caused by lateral forces on cross slopes). Classified operation standards must be formulated based on slope gradient, operation direction (ascending/descending/cross-slope), and load status, supplemented by vehicle, personnel, and environmental control measures. The following is an actionable implementation plan.
1. Slope Classification and Operation Permission Definition
First, clarify the slope threshold (based on industrial vehicle safety standards). Different slopes correspond to different operation rules, and operations beyond the limits are strictly prohibited.
| Slope Class | Slope Range (°) | Permitted Operation Types | Core Restriction Requirements |
| Gentle Slope | ≤3° | Heavy-load ascending/ descending, no-load traveling | Normal speed limit applies; no special modification required |
| Moderate Slope | 3°~5° | Heavy-load ascending, no-load descending | Anti-slip mode must be activated; load weight must be restricted |
| Steep Slope | 5°~8° | No-load ascending /descending only | Heavy-load operations are prohibited; anti-tipping devices must be installed |
| Excessive Slope | ＞8° | Operation prohibited | Road surface must be leveled before operation |
Note: For some warehouse forklifts (e.g., electric stackers), the maximum climbing capacity specified by the manufacturer is ≤5°, which shall prevail according to the equipment manual.
2. Stability Operation Specifications for Slopes of Different Gradients
(1) Longitudinal Slope Operations (Forklift Parallel to the Slope, Divided into Ascending and Descending)
1.1 Heavy-load Ascending Operations (Center of Gravity Shifts Rearward; Prevent Rear-wheel Slippage/Longitudinal Forward Tipping)
Operation Steps | Execution Standards | Stability Control Key Points |
|---|---|---|
Pre-operation Preparation | 1.Check tire pressure (increase pneumatic tire pressure by 5%~10% to enhance grip); 2. Verify that the braking system has no partial braking and responds sensitively; 3. Place the load centrally, tilt the mast backward to the limit, and keep the forks 10~15cm off the ground | Prevent center-of-gravity s hift forward caused by load tilting forward; ensure tire tread depth ≥3mm, otherwise ｒｅｐｌａｃｅ with anti-slip tires |
Driving Operation | 1.Shift to low gear (for internal combustion forklifts) /activate climbing mode (for electric forklifts) and drive at a constant speed; 2. Keep the steering wheel straight; strictly prohibit steering or gear shifting; 3. Control speed at ≤3km/h; avoid sudden acceleration | Sudden acceleration may cause rear-wheel slippage and vehicle loss of control; steering will disrupt longitudinal balance |
Stopping on Slope | 1.If stopping is required, gently step on the brake to decelerate first, then engage the parking brake; 2. Lower the forks to the ground and keep the mast tilted backward; 3. Strictly prohibit long-term idling and parking on the slope | Failure to engage the parking brake may cause the vehicle to roll; a suspended load will exacerbate center-of-gravity shift |
1.2 Heavy-load Descending Operations (Center of Gravity Shifts Forward; Prevent Longitudinal Forward Tipping/Brake Failure)
Core Principle: Heavy-load descending must be performed in reverse gear (load at the rear, counterweight at the front to balance the center of gravity); forward driving is strictly prohibited.
| Operation Steps | Execution Standards | Stability Control Key Points |
Pre-operation Preparation | 1.Check the braking system (brake pad thickness ≥5mm, sufficient brake fluid); 2. Tilt the mast backward, keep the forks 10~15cm off the ground, and face the load toward the driver; 3. Turn off the high-speed gear and activate the speed-limiting mode | Forward driving with the load at the front will cause the center of gravity to shift forward due to downhill inertia, leading to a high risk of longitudinal forward tipping |
| Driving Operation | 1.Drive in reverse at a constant speed with the speed ≤2km/h; 2. Use the foot brake to control speed; strictly prohibit coasting in neutral; 3. Hold the steering wheel firmly with both hands and keep eyes on the road behind | Coasting in neutral may cause brake failure; a dedicated person must direct the operation during reverse driving to avoid collisions |
| At Slope Termination | 1.Decelerate slowly and smoothly drive onto flat ground; 2. Adjust the mast tilt angle only after the vehicle is completely stable | The junction between the slope and flat ground is prone to jolting; sudden braking must be avoided |
1.3 No-load Slope Operations
- No-load ascending: Drive forward, tilt the mast forward to the limit (to lower the center of gravity), and pass at a low constant speed.
- No-load descending: Forward driving is allowed; gently step on the brake to control speed, and strictly prohibit coasting.
(2) Cross-slope Operations (Forklift Perpendicular to the Slope; Extremely High Risk)
During cross-slope operations, gravity generates lateral forces, which may easily cause lateral tipping and thus require strict control:
- Prohibited Behaviors: Heavy-load traveling, turning, loading, and unloading on cross slopes are strictly prohibited; no-load traveling on gentle slopes (≤3°) must be conducted with extreme caution.
- Permitted Operations: Only no-load slow traveling is allowed, subject to the following requirements:
- Speed ≤1km/h; keep the vehicle moving straight; strictly prohibit steering.
- Tires must have good grip; the road surface must be free of oil stains and water accumulation.
- A dedicated person must supervise from the side and immediately stop the vehicle if it tilts laterally.
- Emergency Handling: If the vehicle tilts laterally, stop immediately, slowly adjust the direction to drive away from the slope, and strictly prohibit braking or accelerating.
3. Supporting Assurance Measures for Slope Operation Stability
3.1 Vehicle Technical Assurance
- Install Auxiliary Devices: For steep slope operations, install anti-roll devices (e.g., parking brake boosters), anti-slip chains (for icy and snowy slopes), and tipping warning systems (for real-time monitoring of center-of-gravity shift).
- Regular Calibration: Inspect the sensitivity of the braking system and tire adhesion monthly; calibrate the mast tilt limit device quarterly to ensure the backward tilt angle complies with the manufacturer’s requirements.
- Counterweight Inspection: Ensure electric forklifts have sufficient battery power (when power is below 30%, the equivalent counterweight effect weakens, and slope operations are prohibited); inspect the fixing bolts of the rear counterweight of internal combustion forklifts to ensure no loosening or loss.
3.2 Environmental Control Measures
- Road Surface Treatment: The slope surface must be anti-slip treated (e.g., laying anti-slip steel plates, grooving); remove oil stains, water accumulation, and debris; install guardrails on both sides of the slope to prevent the vehicle from sliding off.
- Slope Signage: Mark the slope gradient, maximum allowable load, and operation direction at the slope entrance (e.g., "5° slope; reverse driving required for heavy-load descending") and post speed limit signs.
- Lighting and Command: Install explosion-proof lighting in dim environments; assign a dedicated person to direct steep slope operations using standard hand signals (e.g., stop, decelerate, reverse).
3.3 Personnel Training and Assessment
- Specialized Training: Incorporate slope operation into the certification assessment for operators, focusing on reverse driving skills for heavy-load descending and emergency handling of tipping incidents.
- Emergency Drills: Organize slope tipping emergency drills quarterly to train operators on the correct response actions: "do not jump off the vehicle, hold the steering wheel firmly, and lower the load slowly".
- Qualification Control: Unauthorized personnel and new employees are strictly prohibited from independently conducting steep slope operations; they must operate under the supervision of senior employees.
4. Slope Operation Stability Hidden Hazard Inspection Checklist
Inspection Item | Inspection Content | Acceptance Standard | Rectification Time Limit |
Slope Compliance | Measure the actual slope gradient | Complies with operation permission definition; no excessive slopes | Immediate rectification |
Vehicle Condition | Braking system, tires, counterweight | No partial braking; tire tread depth ≥3mm; counterweight is firm | Rectification within the shift |
Operation Behavior | Whether reverse driving is adopted for heavy-load descending; whether speed exceeds the limit | Strictly implement reverse driving; speed ≤ standard value | Immediate correction |
Environmental Conditions | Road surface anti-slip performance, lighting, on-site command | Road surface free of oil stains; sufficient lighting; dedicated command | Rectification within the shift |
