Overheadcraneoperators must undergo training and pass an examination, and only those who hold an operation certificate are allowed to operate independently. Without special training and passing the relevant examination, one shall not operate alone. This is a fundamental requirement to ensure that operators have the necessary professional knowledge and skills to handle the equipment safely. Adequate training covers various aspects such as the structure and principle of the crane, operation procedures, and emergency response measures. By obtaining an operation certificate, it proves that the operator has met the required standards and is competent for the job.
Before starting thecrane, a thorough inspection should be carried out on the mechanical, electrical parts, and protective insurance devices of the equipment to ensure they are in good condition and reliable. If the main accessories such as the controller, brake, limit switch, electric bell, and emergency switch are malfunctioning, hoisting is strictly prohibited. The mechanical parts, including the lifting mechanism, running mechanism, and slewing mechanism, need to be checked for any signs of wear, looseness, or damage. The electrical system should be inspected for proper wiring, insulation, and functionality. The protective insurance devices, such as limit switches and emergency stop buttons, play a crucial role in preventing accidents and ensuring the safety of the operation.
Operators must follow the instructions of the hook and lifting personnel. However, for any emergency stop signal issued by anyone, thecraneshould be stopped immediately. This emphasizes the importance of clear communication and the operator’s responsiveness to potential safety threats. The hook and lifting personnel are responsible for guiding the crane operation based on the specific requirements of the lifting task. The operator should maintain close communication with them to ensure the smooth and safe execution of the operation. At the same time, the ability to respond promptly to emergency stop signals is essential to prevent accidents in case of unexpected situations.
Overhead crane operators must start the operation only after receiving the command signal. When starting the crane, the bell should be rung first. This is to notify people in the vicinity of the crane’s operation and to ensure that they are aware of the upcoming movement. The command signal serves as a clear indication for the operator to start the operation, and it helps to coordinate the activities between the operator and other personnel involved in the lifting process. Ringing the bell before starting the crane is a simple but effective safety measure to prevent collisions and ensure the safety of people and property in the surrounding area.
When operating the controller handle, it should first be shifted from the “0” position to the first gear, and then the speed should be increased or decreased gradually. When changing the direction, it must be shifted back to the “0” position first. This step-by-step operation method helps to control the speed and direction of the crane smoothly and prevents sudden changes in speed or direction that could cause instability or accidents. By starting from the “0” position and gradually increasing or decreasing the speed, the operator can have better control over the crane’s movement and ensure the safety of the load being lifted.
When approaching the hoisting limiter, when the trolley or the main crane is near the terminal, or when encountering a neighboring crane, the speed should be slowed down. It is not allowed to use reverse operation instead of braking, use the limit switch instead of stopping the crane, or use the emergency switch instead of the normal switch. These restrictions are in place to prevent overtravel, collisions, and other accidents. The hoisting limiter and terminal limit switches are safety devices designed to prevent the crane from exceeding its safe operating range. Using them properly is crucial for ensuring the safety of the crane and the surrounding environment.
Operators should walk and go up and down on the specified safety walkways, special platforms, or ladders. Walking on both sides of the main crane track is not allowed except for maintenance purposes, and walking on the trolley track is strictly prohibited. It is also not allowed to cross from one crane to another. These safety regulations are designed to prevent operators from falling or being involved in accidents caused by improper movement on the crane. The specified safety walkways, platforms, and ladders provide a safe route for operators to move around the crane, and following these regulations helps to ensure their personal safety.
During work breaks, the lifted load should not be left suspended in the air. When running, if there are people on the ground or when lowering the lifted load, the bell should be rung to give a warning. It is strictly prohibited for the lifted load to pass over people’s heads. The lifted load should not be lifted more than 2 meters above the ground. These measures are to protect the safety of people on the ground and prevent potential hazards caused by the suspended load. Leaving the load suspended in the air during breaks can pose a risk of accidental falling, and warning signals are necessary to alert people in the vicinity of the crane’s operation.
When two cranes are lifting an object simultaneously, they should follow the command and move in unison. This requires good coordination and communication between the operators of the two cranes. Each crane should bear an appropriate share of the load, and the lifting speed and direction should be synchronized to ensure the stability of the lifted object. Special attention should be paid to the balance of the load to prevent it from tilting or falling during the lifting process.
When running, a certain distance should be maintained between cranes, and crashing into other cranes is strictly prohibited. When two cranes running on the same wall crane need to pass each other, the crane should move the trolley to take the initiative to avoid collision. Maintaining a safe distance between cranes is essential to prevent collisions and ensure the normal operation of multiple cranes in the same area. The ability to take the initiative to avoid collisions when necessary demonstrates the operator’s awareness of safety and the importance of following safety regulations.
When repairing the crane, it should be parked at a safe location. The power supply should be cut off, and a “No Closing” warning sign should be hung. A fence should be set up on the ground, and a “No Passage” sign should be hung. These safety measures are to prevent accidental start-up of the crane during the repair process and to ensure the safety of the repair personnel. Cutting off the power supply and hanging warning signs are basic safety precautions to prevent unauthorized access to the crane and to ensure that the repair work is carried out in a safe environment.
When lifting a heavy object, it should be slightly lifted off the ground first for a trial lift. After confirming that the suspension is stable and the braking is good, then it can be lifted higher and run slowly. It is not allowed to operate three control handles simultaneously. The trial lift is an important step to check the stability of the load and the effectiveness of the crane’s braking system. By lifting the load slightly off the ground, the operator can observe any signs of instability or abnormal movement. Operating multiple control handles simultaneously can make it difficult to control the crane’s movement accurately and increases the risk of accidents.
When the crane is running, it is strictly prohibited for anyone to get on or off. It is also not allowed to carry out maintenance and adjustment of the machine parts during operation. This is to prevent people from falling or being injured by the moving parts of the crane. The crane’s operation is a complex and potentially dangerous process, and any unauthorized access or maintenance during operation can pose a serious threat to the safety of personnel.
In case of a sudden power outage during operation, the switch handle must be placed in the “0” position. If the lifted object has not been lowered or the rigging has not been unhooked, the operator is not allowed to leave the cab. Placing the switch handle in the “0” position in case of a power outage helps to prevent the crane from restarting unexpectedly when the power is restored. And the operator’s presence in the cab is necessary to ensure that they can take appropriate measures to deal with the situation and ensure the safety of the lifted object.
Before casting, the height of the molten steel ladle should be checked first. Then ring the bell and run at a slow speed; when casting steel, the lowering speed should be slow and stable. This is to ensure the safety of the casting process and prevent molten steel from splashing or overflowing. Checking the height of the molten steel ladle helps to determine the appropriate lifting and lowering operations, and running at a slow speed and maintaining a stable lowering speed are important for ensuring the quality and safety of the casting.
When a sudden failure during operation causes molten steel leakage or the lifted object to slide down, emergency measures must be taken to lower it to an area where there are no people. This requires the operator to have quick judgment and the ability to respond appropriately in case of an emergency. The safety of people is the top priority, and taking immediate action to move the dangerous object to a safe area can minimize the potential harm caused by the accident.
In case of a violent storm, lightning strike, or wind force of level 6 or above for an outdoor crane, the work should be stopped, the power supply should be cut off, and the wheels should be blocked with pads in front and behind. These safety measures are to prevent the crane from being damaged by strong winds or lightning and to ensure the safety of the equipment and personnel. Outdoor cranes are more vulnerable to adverse weather conditions, and taking appropriate preventive measures can reduce the risk of accidents.
Sufficient lighting should be provided for night operations. Good lighting is essential for ensuring the visibility of the crane’s operation and the safety of the operator. It helps the operator to clearly see the surrounding environment, the lifted object, and any potential obstacles. Without sufficient lighting, the risk of accidents increases significantly, especially in complex working environments.
The safety operation of the gantry crane should be carried out in accordance with these regulations. When driving, pay attention to whether there are any obstacles on the track; when lifting a large object that obstructs the line of sight, special personnel should be assigned on both sides to monitor and command. The gantry crane has its own characteristics and operating requirements, and following the relevant regulations is crucial for ensuring its safe operation. Monitoring and commanding by special personnel can help the operator to better handle the situation when the line of sight is obstructed and ensure the safety of the lifting operation.
Overhead crane operators must earnestly implement the “Ten No Hoisting” principles: (1) Do not hoist if the load exceeds the rated load. Overloading the crane can cause serious damage to the equipment and pose a great risk of accidents. Each crane has a specified rated load, and operating within this limit is essential for ensuring the safety and reliability of the crane. (2) Do not hoist if the command signal is unclear, the weight is unknown, or the lighting is dim. Clear communication and accurate information about the load are necessary for a safe lifting operation. Unclear signals or unknown weights can lead to misoperation, and dim lighting can affect the operator’s visibility and judgment. (3) Do not hoist if the lifting rope and accessories are not securely tied and do not meet the safety requirements. The lifting rope and accessories are crucial for supporting the load, and their proper installation and safety are essential. Insecure ties or non-compliance with safety requirements can cause the load to fall off during the lifting process. (4) Do not hoist if the crane is directly processing the suspended heavy object. The crane is designed for lifting and moving objects, not for processing them. Directly processing the suspended object can cause damage to the crane and pose a risk to the operator and the surrounding environment. (5) Do not hoist if the object is pulled obliquely. Oblique pulling can cause uneven stress on the lifting rope and the object, increasing the risk of the rope breaking or the object falling. It is important to ensure that the object is lifted vertically to maintain its stability. (6) Do not hoist if there are people standing on the workpiece or there are moving objects on the workpiece. The presence of people or moving objects on the workpiece can pose a serious threat to their safety. The operator should ensure that the workpiece is clear of any people or objects before lifting. (7) Do not hoist explosive objects such as oxygen cylinders and acetylene generators. These objects are highly dangerous and require special handling procedures. Hoisting them with a crane without proper precautions can lead to serious accidents. (8) Do not hoist if the sharp edges and corners of the object are not padded. Padding the sharp edges and corners can prevent the lifting rope from being damaged and ensure the safety of the lifting operation. Without proper padding, the rope may be cut or worn, increasing the risk of the load falling. (9) Do not hoist objects buried in the ground. Objects buried in the ground may be tightly fixed or have unknown conditions, and hoisting them without proper assessment can cause damage to the crane and the object itself. (10) Do not hoist if the molten steel is too full and the fixing clips have not been installed. Molten steel is a high-temperature and dangerous substance, and ensuring its stability during lifting is crucial. The fixing clips are used to prevent the molten steel from overflowing, and their absence can pose a great risk of accidents.
After the work is completed, the crane should be parked in the specified position, the hook should be raised, the trolley should be driven to both ends of the track, and the control handle should be placed in the “0” position, and the power supply should be cut off. This is to ensure the safety of the crane during the idle state and to prepare it for the next operation. Parking the crane in the specified position and properly storing the trolley and the hook can prevent damage to the crane and ensure the safety of the surrounding environment. Placing the control handle in the “0” position and cutting off the power supply are important safety measures to prevent accidental start-up of the crane.
In conclusion, the safety operation of overhead cranes requires strict compliance with these requirements by operators. Each requirement is designed to prevent accidents and ensure the safety of personnel and equipment. By following these regulations, we can minimize the risks associated with crane operations and create a safe working environment. At the same time, continuous training and education for operators are also necessary to improve their safety awareness and operational skills, further enhancing the safety of crane operations.
