The technical parameters of agrúarepresent its working capacity and serve as the fundamental basis for designing the crane. The main technical parameters of a crane include: lifting capacity, lifting height, amplitude, operating speed of the mechanism, productivity, slewing radius, and lifting torque.
(I) Lifting Capacity
The maximum mass that agrúais allowed to lift at one time during normal operation is called the rated lifting capacity. The unit is tons (t) or kilograms (kg). The rated lifting capacity is a crucial parameter that determines the scope of work the crane can undertake. It is carefully calculated and specified during the design and manufacturing process of thegrúato ensure the safety and reliability of the crane’s operation. Exceeding the rated lifting capacity can lead to serious consequences, such as damage to the crane structure, failure of the lifting mechanism, or even accidents.
(II) Lifting Height
The lifting height refers to the vertical distance that the crane can lift the load from the lowest position to the highest position. It is an important parameter that affects the crane’s ability to operate in different working scenarios. Por ejemplo, in some shipyard operations, a sufficient lifting height is required to handle large ship components or equipment at different heights. In marine crane operations, the lifting height needs to be carefully considered according to the specific requirements of the work, such as the height of the ship’s deck, the depth of the cargo hold, and the height of the storage area.
II. Correct and Standardized Operation
First, the lifting machinery must be operated by a specially assigned person. It is strictly prohibited for non-operators to operate the crane. This is to ensure that the crane is operated by personnel who have received professional training and are familiar with the operation procedures and safety regulations of the crane. Only a specially assigned operator can handle the crane in a timely and accurate manner in case of emergencies, reducing the risk of accidents.
Second, the crane driver must hold a special type of work operation certificate to operate independently. The special type of work operation certificate is a proof that the driver has the necessary skills and knowledge to operate the crane safely. It is issued after the driver has passed strict training and assessment. The training covers various aspects, including the structure and principle of the crane, operation skills, safety regulations, and emergency response measures.
Third, the lifting machinery is prohibited from being used in any of the following situations:
The wire rope reaches the scrapping standard. The wire rope is a key component of the crane for lifting the load. Once it reaches the scrapping standard, its strength and reliability are greatly reduced, and there is a high risk of breakage during operation, which may lead to the falling of the load and cause serious accidents.
The hook, pulley, and drum reach the scrapping standard. These components are also crucial for the normal operation of the crane. When they reach the scrapping standard, they may not be able to perform their functions properly, such as the hook may not be able to securely hold the load, and the pulley and drum may have problems with smooth rotation, all of which pose potential safety hazards.
The braking torque of the brake cannot hold the rated load. The brake is an important safety device of the crane. If the braking torque is insufficient, the crane may not be able to stop the load in time during operation, which may lead to collisions or other accidents.
The limit switch fails. The limit switch is used to prevent the crane from exceeding its safe operating range. When it fails, the crane may continue to operate beyond the limit, resulting in damage to the crane or the surrounding environment.
The main stressed components have cracks or open welds. Cracks and open welds in the main stressed components will seriously affect the structural strength of the crane. Under the action of loads, these defects may expand rapidly, leading to the collapse of the crane structure.
The elastic deformation or permanent deformation of the main beam exceeds the repair limit. The main beam is the main load-bearing component of the crane. Excessive deformation will affect the stability and safety of the crane. If the deformation exceeds the repair limit, the crane needs to be repaired or replaced in time.
The electrical zero connection protection fails or the insulation does not reach the specified value. Electrical safety is an important part of crane operation. If the electrical zero connection protection fails or the insulation is insufficient, there is a risk of electric shock or electrical fire, endangering the safety of personnel and equipment.
The motor temperature rise exceeds the specified value. The motor is the power source of the crane. Excessive temperature rise indicates that the motor may be overloaded or there are problems with its cooling system. Continuing to operate the crane in this situation may damage the motor and affect the normal operation of the crane.
The wind force reaches level six or above. Strong winds can have a significant impact on the stability of the crane. When the wind force reaches level six or above, the crane may be blown out of balance, resulting in accidents such as tipping over. Therefore, it is necessary to stop the operation of the crane in strong winds.
The newly installed, modified, or overhauled crane has not passed the inspection and acceptance. Newly installed, modified, or overhauled cranes need to go through strict inspection and acceptance procedures to ensure that they meet the safety and performance requirements. Only after passing the inspection and acceptance can the crane be put into use.
Fourth, the operator should do the following:
It is strictly prohibited to drink alcohol before work. Alcohol can affect the operator’s judgment, reaction speed, and coordination ability, increasing the risk of accidents. Therefore, the operator must stay sober and focused during work.
Do not allow irrelevant personnel to get on the crane. The crane operation area is a high-risk area, and the presence of irrelevant personnel may interfere with the operator’s work or cause unexpected situations. Keeping the crane operation area free of unnecessary people can ensure the safety of both the operator and the equipment.
Before starting the crane, first check whether the mechanical, electrical, and safety devices are in good condition; check whether there are any objects that can be bumped, stuck, or hung on the crane; confirm that everything is normal, ring the bell to give a warning, and then power on for a test run. This pre-operation inspection is an important step to ensure the normal operation of the crane. By carefully checking all aspects of the crane, potential problems can be detected and resolved in a timely manner, reducing the risk of accidents during operation.
If any of the situations specified in the third point is found during the inspection and test run, the crane should be stopped immediately. Timely stopping the crane can prevent the problem from expanding and avoid more serious consequences.
During operation, the operator must concentrate and cooperate closely with the commander. It is not allowed to smoke, eat, or talk to others during operation. Concentration and close cooperation are essential for safe crane operation. Smoking, eating, or talking to others may distract the operator’s attention, leading to operational errors.
Strictly implement the “Ten No Lifting” during operation:
Do not lift if the load exceeds the rated load. Overloading the crane is a very dangerous behavior that can cause serious damage to the crane and pose a threat to the safety of personnel and property.
Do not lift if the command signal is unclear, the weight is unknown, or the light is dim. Clear command signals, accurate weight information, and good lighting conditions are necessary for safe lifting operations. Without these conditions, the operator may not be able to make correct judgments and operations.
Do not lift if the lifting sling and accessories are not firmly tied or do not meet the safety requirements. Loose or unsafe binding of the lifting sling and accessories may cause the load to fall off during lifting, resulting in accidents.
Do not lift if the hanging weight is directly processed. Directly processing the hanging weight while it is being lifted can cause instability of the load and pose a risk to the operator and the equipment.
Do not lift if it is tilted and obliquely hung. Tilted and obliquely hung loads will cause uneven stress on the crane and the lifting sling, increasing the risk of accidents.
Do not lift if there are people on the workpiece or floating objects. The presence of people or floating objects on the workpiece can pose a serious threat to the safety of personnel. It is necessary to ensure that the workpiece is clear of any people or objects before lifting.
Do not lift flammable and explosive items. Flammable and explosive items require special handling procedures and safety measures. Lifting them with a crane without proper precautions can lead to serious accidents such as explosions and fires.
Do not lift items with sharp edges and corners without padding. Padding items with sharp edges and corners can prevent damage to the lifting sling and ensure the safety of the lifting operation.
Do not lift buried objects. Buried objects may have unknown weights and conditions, and lifting them without proper assessment can cause damage to the crane and the surrounding environment.
Do not lift if there is illegal command from the cadre. Operators should abide by safety regulations and resist illegal commands. Illegal commands may lead to dangerous situations and should be firmly refused.
During operation, always ensure stable lifting, stable operation, and stable lowering. When approaching adjacent vehicles or people, it is necessary to ring the bell to give a warning in a timely manner. Stable operation can reduce the impact and vibration of the crane, protecting the crane and the load. Ringing the bell to give a warning can alert nearby people and vehicles to pay attention to the crane’s operation and avoid collisions.
When lifting items, adhere to the “Three No Overs” principle:
Do not cross over people’s heads. Lifting items over people’s heads is extremely dangerous and can cause serious harm to people.
Do not cross over the heads of cars or trains. Crossing over cars or trains may cause damage to the vehicles or interfere with their normal operation.
Do not cross over equipment. Crossing over equipment may damage the equipment or pose a risk to the crane’s operation.
During operation, stop the crane immediately when anyone gives a stop signal. This ensures that the crane can be stopped in time in case of emergencies, reducing the risk of accidents.
When the grab is working, in order to avoid the items from falling out, the grab should be closed tightly and no shaking is allowed. A tightly closed grab can ensure the stability of the load and prevent it from falling during lifting and transportation.
Before the grab is fully closed, the grab should be slightly lifted and then closed again to prevent overloading. This operation can ensure that the grab is properly positioned and can prevent excessive force from being applied to the grab and the crane, reducing the risk of overloading.
When the grab is lifted, the load should be evenly transmitted to each wire rope. Uneven load distribution on the wire ropes can cause some wire ropes to bear excessive stress, reducing their service life and increasing the risk of breakage.
Before the grab works, each mechanism needs to be run empty for a short time to check whether it is normal. This pre-operation empty run can help detect any problems with the grab mechanism, such as abnormal noise or uneven movement, and allow for timely repairs and adjustments.
When the grab grabs fixed items, do not lift it to unload and break the items. Do not grab hard items with irregular shapes. These operations can cause damage to the grab and the crane, and may also pose a safety hazard.
The sum of the weight of the grab and the heavy object shall not exceed the rated lifting capacity. Exceeding the rated lifting capacity can lead to overload and potential accidents.
When not working, the grab should be lowered to the ground. This can prevent the grab from being damaged due to hanging in the air for a long time and also ensure the safety of the working area.
Fill in the shift handover record carefully, especially the unsafe factors must be clearly explained. The shift handover record is an important document for the continuous and safe operation of the crane. By clearly recording the operating status of the crane, any problems found, and the measures taken, the next operator can have a comprehensive understanding of the crane’s situation and take appropriate actions.
En conclusión, the operation of marine cranes requires strict compliance with relevant regulations and operating procedures. Each step of the operation is related to the safety of personnel and equipment. By understanding and implementing these precautions, we can ensure the safe, efficient, and stable operation of marine cranes, and contribute to the smooth progress of marine engineering and shipping operations. Además, with the continuous development of marine technology and the increasing complexity of crane operations, it is necessary to continuously improve the operation and management level, strengthen personnel training, and update equipment to adapt to new challenges and requirements. Regular maintenance and inspection of the crane are also essential to ensure its good working condition and extend its service life. Only in this way can we effectively prevent accidents and ensure the sustainable development of the marine industry.
