Analysis of Safety Precautions for Practical Operation of Portal Cranes

Portal cranes are core heavy lifting equipment in ports, factories, mines, and infrastructure projects. With their large operating radius, high load-bearing capacity, and flexible operation, they are widely used in cargo loading and unloading, equipment hoisting, and material transfer. This equipment is classified as special equipment due to its complex structure and high dynamic operation risks. Improper operation can easily lead to equipment damage, cargo falling, and personal injury. Therefore, operators must strictly adhere to operating procedures, control every detail of the entire operation process, standardize practical actions, and build a solid safety barrier for lifting operations. This article comprehensively reviews the core precautions for each stage of portal crane operation based on actual field conditions, providing a reference for standardized safe operation.

I. Pre-operation Preparation: Strict Pre-operation Inspection to Eliminate Initial Hazards

Adequate pre-operation preparation is the first line of defense against safety accidents. Operators must adhere to the principle of "no operation without inspection, no start of work without briefing," conducting a comprehensive check from four dimensions: personnel, equipment, site, and environment.

At the personnel level, operators must hold valid special equipment operation qualification certificates. Unlicensed personnel or those with expired certificates are strictly prohibited from operating equipment. Operating under the influence of alcohol, while fatigued, or while ill is strictly prohibited. Working under conditions of excessive emotional fluctuation or lack of concentration is also strictly prohibited. Simultaneously, safety helmets, non-slip shoes, protective gloves, and other personal protective equipment must be worn according to regulations. Throughout the operation, unauthorized departure from the post, wandering between posts, or using mobile phones is strictly prohibited; maintaining a focused state of mind is essential. When multiple people are working together, a safety briefing must be completed in advance, clearly defining the responsibilities of the driver, signalman, and slinger, and standardizing hand gestures and walkie-talkie communication commands to prevent confusion and disjointed coordination.

Equipment inspection is the core of pre-production preparation. First, verify the entire steel structure, focusing on key components such as the gantry, boom, slewing platform, and traveling mechanism, confirming no defects such as deformation, cracks, weld detachment, or loose bolts. Second, inspect the core operating mechanisms: ensure the hoisting, luffing, slewing, and traveling mechanisms operate smoothly without jamming or abnormal noise; check the brakes for sensitive and reliable braking; and ensure the foot-operated slewing brake's hydraulic circuit is clean and free of oil stains and foreign matter. Simultaneously, comprehensively verify all safety protection devices: limit switches, buffers, torque limiters, overload protectors, and emergency stop switches must be sensitive and effective; operation is strictly prohibited if any safety device malfunctions. Finally, inspect auxiliary components: ensure the wire rope is free of broken wires, broken strands, rust, and deformation, and that the rope ends are securely fixed; check the hook for cracks and excessive wear, and ensure the anti-derailment safety device is intact; and ensure that the lifting gear and rigging are of the correct specifications, securely bound, and free from damage or aging.

On-site and environmental verification is also crucial. Clear obstacles and irrelevant materials from the work radius in advance, demarcate a dedicated work warning zone, and prohibit unauthorized personnel from entering, loitering, or passing through. Accurately verify the weight and center of gravity of the hoisted goods, and strictly prohibit vague estimations of the load. At the same time, monitor the working environment in real time. Crane operations must be stopped in severe weather conditions such as level 6 or above winds, heavy rain, dense fog, sandstorms, or when lighting is dim or visibility is obstructed, and risky operations must be avoided.

II. Operational Procedures: Strictly Adhere to Standardized Procedures and Eliminate Violations

The operation process is a critical stage for risk prevention and control. Operators must adhere to the operating principles of "stable, low-speed, precise, and controllable" operation, strictly avoid all violations, and complete the entire process of lifting, transferring, and lowering in a standardized manner.

Equipment startup must be gradual. After starting, conduct a no-load test run, sequentially testing the lifting, luffing, slewing, and traveling movements. Check the operation, braking, and limit functions of each mechanism to ensure they are normal. Only after confirming that the equipment is free of abnormalities can formal lifting operations commence. Throughout the operation, strictly adhere to the "Ten No-Lifting Rules": No lifting if overloaded, unclear command, insecure binding, oblique pulling or lifting, buried objects, personnel standing on the object being lifted, malfunctioning safety devices, poor lighting, unprotected sharp edges, or excessive wind. These are core principles for preventing lifting accidents and must be strictly enforced without any slackening.

Lifting operations must adhere to the principle of stability and controllability. When lifting, raise the hook slowly, first lifting the load slightly off the ground by 10-20 cm. Pause the operation to check the load's balance, rigging tension, and equipment braking status. Only after confirming there is no tilting, loosening, or abnormality can the load be lifted smoothly. Rapid lifting and sudden acceleration are strictly prohibited. During transport, lifting, luffing, slewing, and traveling movements must be slow and uniform. Sudden starts, stops, turns, and drops are prohibited to avoid significant swaying, swinging, or rotation of the load. Goods must be lifted vertically; oblique lifting is strictly prohibited to prevent lateral stress on the equipment, which can cause boom deformation, wire rope wear, and equipment overturning.

During operations, monitor the dynamic status in real time. Keep a close eye on the load, the operating radius, and the surrounding environment. Observe the wire rope tension, equipment operation, and load stability at all times. If any abnormalities are found, such as load swaying, loose rigging, or unusual equipment noises, immediately and smoothly lower the hook, stop the machine, and investigate. It is strictly forbidden to continue operation with faults or potential hazards. When the load is suspended in the air, operators are strictly prohibited from leaving their posts and from standing, passing, or working under the load. The operating height and distance must be precisely controlled. When crossing obstacles, the bottom of the load must be at least 30 centimeters higher than the obstacle to prevent collisions and scrapes.

Furthermore, it is strictly forbidden to alter operating procedures without authorization, to overload the equipment, to use cranes to pull or drag fixed objects on the ground, or to use limit devices to replace conventional braking operations. When multiple machines are working together or in close proximity, sufficient safety distance must be maintained, and the operating rhythm must be unified to avoid interference and collision between equipment and suspended loads.

III. Emergency Failure Handling: Respond calmly and according to procedures to avoid secondary risks.

In the event of a sudden power outage, brake failure, mechanism jamming, or wire rope malfunction during the operation of a gantry crane, operators must remain calm and avoid panicked or reckless actions. Emergency procedures must adhere to the principle of "protecting personnel, controlling the load, and stabilizing the equipment."

In the event of a sudden power outage, immediately reset all operating handles to zero, disconnect the equipment control power, remain at your post, and strictly prohibit unauthorized climbing of the equipment or unauthorized repairs. After power is restored, first test the equipment performance under no-load conditions, and only resume operation after confirming there are no abnormalities. If the load is suspended in mid-air during a power outage, wait for qualified personnel to use emergency devices to safely lower the load; unauthorized operation is strictly prohibited.

In the event of brake failure, such as a failure of the hoisting mechanism brake, immediately switch to a low speed gear and slowly operate the luffing and slewing mechanisms to move the load to an open, safe, and uninhabited area. Use auxiliary braking devices to control the load, and after a smooth landing, stop the crane for inspection. If the slewing or traveling brakes fail, immediately stop all operations and use the surrounding environment and emergency devices to slow down the equipment and prevent drifting or collisions.

If you discover severe shaking, abnormal noise, or excessive broken wires in the wire rope, or abnormal deformation of the boom or steel structure, immediately stop all operations, slowly unload and lower the hook, shut down the machine, disconnect the power, set up warning signs, and report to management for inspection. Do not restart the machine until the fault has been completely resolved and accepted.

In case of sudden strong winds, heavy rain, or other severe weather, immediately stop hoisting operations, gently lower the load to the ground, retract the boom to a safe range, lock the traveling mechanism and anchoring equipment, disconnect the main power, and ensure the equipment is protected against wind and rain to avoid the risk of equipment overturning or structural damage.

IV. Post-Operation Cleanup: Standardized Shutdown and Reset, Closed-Loop Management After each operation, standardized cleanup procedures are crucial for ensuring long-term equipment safety and extending its service life. Strict implementation of four steps is required: equipment reset, site cleanup, record keeping and reporting, and equipment protection.

After resetting the equipment according to specifications, move and park the crane to the designated safe position, retract the boom to the standard safe range, raise the unloaded hook to the upper limit safe position, tighten the wire rope, return all operating handles to the zero position, turn off the equipment operating power and main power, and lock the equipment.

Thoroughly clean the work site, remove warning signs, clear debris, tools, and remaining materials from the work area, and organize rigging and lifting equipment, storing them in designated locations to maintain a clean and orderly work area.

Complete work records, accurately filling out the equipment operation log, recording work duration, lifting load, equipment operating status, any malfunctions or anomalies, and their handling, ensuring traceability of operations and documentation of potential hazards. Report any potential equipment defects or minor malfunctions to the equipment management department promptly to prevent the accumulation of hazards.

Perform basic equipment maintenance, cleaning dust and debris from key components such as wire ropes, pulleys, guide rails, and axles; inspecting component wear; and promptly adding lubricating grease to lubrication points to prevent rust and jamming, ensuring normal start-up and shutdown operations next time. Simultaneously, close the doors and windows of the control room and take measures to prevent dust, rain, and theft.

V. Routine Maintenance and Skill Enhancement: Strengthening the Foundation for Long-Term Safety

In addition to comprehensive control over the entire process of each single operation, routine maintenance and personnel skill enhancement are fundamental guarantees for reducing operational failures and mitigating safety risks. Daily maintenance must be strictly carried out according to the equipment manual, with regular comprehensive inspections and maintenance. Simultaneous maintenance and repairs are strictly prohibited, and maintenance work must be performed while the equipment is running. During maintenance work, a stop-work sign must be displayed, and safety precautions must be implemented.

Operators must routinely study special equipment safety regulations and equipment operating procedures, be familiar with the equipment's structure, performance, fault characteristics, and emergency response methods, and regularly participate in safety training and practical drills to accumulate operational experience and avoid habitual violations and a sense of complacency. At the same time, careless operating habits must be abandoned, and attention to detail must be paid to ensure that every operation is standardized and regulated, reducing operational risks from the source.

Safety in the operation of gantry cranes is of paramount importance. The safety and standardization of lifting operations directly affect personnel safety, equipment condition, and production efficiency. During actual operations, operators must firmly establish the principles of "safety first, prevention foremost, and full control," strictly implementing comprehensive management throughout the entire process: meticulous pre-operation checks, standardized operation during operation, scientific handling of malfunctions, and closed-loop post-operation follow-up. Strict adherence to operating procedures, prevention of violations, and attention to detail and potential hazards are crucial. Only by consistently standardizing operational practices, implementing safety responsibilities, and ensuring proper equipment maintenance can we effectively prevent various lifting accidents, guarantee the safe, stable, and efficient operation of portal cranes, and build a solid safety barrier for production operations.