Lifting machinery is a special equipment. Managers must be trained before they take up their posts. They can only take up their posts after passing the assessment. In the previous article, I shared the theoretical knowledge and practical skills assessment scope of lifting machinery safety management personnel for your reference. Today, I will share with you a test question and answer for the crane management personnel exam. The test questions are divided into judgement questions, multiple choice questions, multiple choice questions and analysis questions. I hope everyone has to help.
1. The mechanical and electrical equipment of lifting machinery which can lift and lower limbs vertically and move heavy objects horizontally. ,mistaken.
2. The wire rope is made of high-quality carbon steel wire twisted, and most of the cranes use single-wound rope. ,mistaken.
3. There are three types of steel wire rope cores: asbestos core, organic core and plastic core. ,mistaken.
4. The steel wire rope with organic core has greater flexibility and elasticity, good lubricity, but can not withstand lateral pressure and high temperature. ,Correct.
5. The metal core wire rope has high strength, can withstand high temperature and lateral pressure, and has good lubrication performance. ,mistaken.
6. The twisting direction of the strands of the same twisted steel wire rope is opposite to the twisting direction of the strands. ,mistaken.
7. The twist direction of the twisted steel wire rope strands is opposite to the twist direction of the strands twisted into the wire rope, so it is widely used on cranes. ,Correct.
8. The winding performance of the alternating twisted steel wire rope is better than that of the same direction twisted steel wire rope, and the service life is long. ,mistaken.
9. The cross-twisted steel wire rope has a short service life due to the poor contact of the outer steel wire between the strands, which is easy to wear. ,Correct.
10. The wire rope rubs against the drum, pulley groove, etc. during the working process, which will cause corrosion. ,mistaken.
11. When the wire rope is used in a corrosive gas and humid environment, pits will be formed on the surface, which is easy to damage the wire rope. ,Correct.
12. The steel wire rope is subjected to mechanical collision, squeezing and bending, flattening and kinking are bending fatigue. ,mistaken.
13. The steel wire rope lubrication should pay special attention not to miss the invisible and inaccessible parts, such as the balance pulley. ,Correct.
14. In the dangerous section of the hook, the inner tensile stress is much smaller than the outer tensile stress, so it is made into a trapezoidal section with a thick inner side and a thin outer side. ,mistaken.
15. The inner tensile stress in the dangerous section of the hook is much larger than the outer tensile stress, so the hook is made into a trapezoidal section with a thick inner side and a thin outer side. ,Correct.
16. Single pulley block is used on starters with heavy lifting capacity. ,mistaken.
17. The double pulley block is composed of two single-line pulley blocks with the same magnification. ,Correct.
18. The reel transfers the driving force to the wire rope, turning the linear motion into a rotary motion. ,mistaken.
19. The rope groove of the jib crane drum rotates in only one direction. ,Correct.
20. When the hook or other retrieval device is placed in the lowest position, remove the number of windings of the fixed rope tail, and there must be no less than five turns of steel wire rope on the reel. ,mistaken.
21. The end of the wire rope should be firmly fixed on the drum to ensure safety and reliability, and it is also easy to check and replace the wire rope. ,Correct.
22. Block brakes can be divided into two types: normally closed and normally open according to their working conditions. ,Correct.
23. When lubricating the junction points of the brake, do not put the lubricating oil on the friction plate or brake wheel. ,Correct.
24. The sealing ring of the hydraulic electromagnetic push rod brake release device should be immersed in new oil injected into the brake release device before installation to prevent the sealing ring from being jammed. ,Correct.
25. The smaller the braking stroke of the brake, the safer it is. ,mistaken.
26. The temperature of the brake wheel is too high, and the smoke from the brake block is mainly caused by improper installation and adjustment. ,Correct.
27. The brake of the lifting mechanism can be adjusted under load. ,mistaken.
28. If the brake is adjusted too loosely, the brake stroke will cause hook walking and collision accidents. ,Correct.
29. If the brake is adjusted too loosely, impact load will occur, strong vibration and rope break accidents will occur. ,mistaken.
30. The tighter the brake is adjusted, the better for safety. ,mistaken.
31. When checking the temperature of the brake wheel, you can judge whether it is burnt or not by touching it by hand. ,mistaken.
32. When the braking stroke of the large vehicle is too large, the brakes will be too strong, causing impacts and shaking of the hanging objects, which will easily deform the bridge frame and damage some parts. ,mistaken.
33. When a load is hoisted, sudden braking will cause an excessive and rapid impact load on the wire rope and cause it to break. ,Correct.
34. The multiple of the increase of the output torque of the reducer, which is equal to the speed ratio of the reducer in value. ,Correct.
35. The sealing requirements of the split surface of the reducer must not be missed. ,Correct.
36. The more oil in the reducer, the better. ,mistaken.
37. There should be no abnormal noise, heat and vibration when the gear transmission is working. ,Correct.
38. The pitting of gear teeth can cause major equipment or personal injury accidents, so this factor is the focus of safety technical inspection. ,mistaken.
39. Gear teeth broken may cause serious equipment or personal injury accidents, so broken teeth and the factors that cause broken teeth are the focus of safety technical inspection. ,Correct.
40. On the lifting electromagnet control switch, there should be obvious words such as "adsorption" and "release". ,Correct.
41. On the housing of the lifting electromagnet, there should be protective measures to prevent the collision end and add a box cover. ,Correct.
42. All bolt connections of the lifting electromagnet should be able to prevent automatic loosening. ,Correct.
43. The lifting electromagnet has a certain delay performance, so it is not dangerous. ,mistaken.
44. The lifting electromagnet should be equipped with a power failure alarm device to take preventive measures in time. ,Correct.
45. One of the causes of electrification of the motor shell is the leakage of the coil between the shells. ,Correct.
46. One of the reasons for the electrification of the motor casing is that the coil conductor and the iron core casing are not connected. ,mistaken.
47. Attention should be paid to prevent the motor from overheating during the work of hoisting machinery. ,Correct.
48. The function of the resistor is to limit the starting, braking current and frequency modulation of the motor. ,mistaken.
49. Resistors can be divided into start-up resistors and start-up speed regulation resistors according to their uses. ,Correct.
50. The contactor is an automatic electrical appliance, through which a smaller control power can be used to control a larger power lighting circuit. ,mistaken.
51. Since the contactor is electromagnetically controlled, it can be remotely controlled and frequently operated, and can realize automatic protection. ,Correct.
52. Do not arbitrarily change the circuit during installation, maintenance, adjustment and use to avoid failure of the safety device. ,Correct.
53. If the safety device of the crane is reliable, the safety device can be used to shut down the operating mechanism of the crane. ,mistaken.
54. Lifting weight limiter and driving torque limiter are mainly used to prevent the lifting weight from exceeding the load capacity of the crane, so as to avoid accidents caused by the breaking of the wire rope and the damage of the lifting equipment. ,Correct.
55. The overloaded use of cranes is one of the important reasons for broken hooks and broken ropes. The overload limiter should be set up in accordance with the regulations and carefully adjusted and checked frequently. ,Correct.
56. The buffer should absorb the energy of the motion mechanism and increase the impact performance. ,mistaken.
57. The operating limiter should ensure that the power source is automatically cut off when the mechanism reaches the limit position. ,Correct.
58. The ascending limiter must ensure that the power supply can be automatically cut off when the hook is raised to the limit position. ,Correct.
59. The movable parts exposed on the crane that may injure people should be equipped with protective covers. ,Correct.
60. The rail end stop should have good performance to prevent cranes from derailing. ,Correct.
61. The position of the buffer should be correct and firm, and it should be skewed to the corresponding striker. ,mistaken.
62. Enter the door of the bridge crane and the Cangkou door of the driver's cab to board the bridge frame, should be four, set up a chain protection device. When the door is opened, the operating mechanism of the crane cannot be started. ,Correct.
63. When the driver's cab is located in the moving part, the access door to the driver's cab should be equipped with a chain protection device. When the door of the access door is opened, the operating structure of the weightlifting machine should be able to start. ,mistaken.
64. A rain cover should be installed on the electrical equipment of the crane working in the open air. ,Correct.
65. The buffer is a decelerating device, which is used to ensure that the crane can stop smoothly without causing a violent impact. ,mistaken.
66. The anchoring device is a supplement to the automatic anti-skid device, and should generally be used in conjunction with other anti-skid devices. ,Correct.
67. Whether the metal structure of the crane or the rail of the cart should be grounded or zeroed should be determined according to the power grid. ,Correct.
68. Repeated grounding can discharge current to the ground, and can play a role in lightning protection. ,Correct.
69. For the grounding inspection of metal structures or cart tracks, first determine whether the neutral point of the power supply transformer is directly grounded. ,Correct.
70. The grounding wire can be used as the current-carrying neutral wire. ,mistaken.
71. The lighting power supply of the crane should be set up with a separate power switch. ,Correct.
72. On the crane, it is allowed to adopt zero-connection protection for some electrical equipment and grounding protection for some electrical equipment. ,mistaken.
73. The rated lifting capacity of a grab crane is the maximum weight that can be grabbed. ,mistaken.
74. The sides or other obvious parts of the crane must be hung with lifting weight signs that can be seen clearly from the ground. ,Correct.
75. The working level of the whole crane is selected based on the comprehensive standard of the busyness of its use time and the number of use per hour. ,mistaken.
76. It is very important to select the working level correctly, otherwise it will affect the working life of the starter and cause the motor to burn out frequently. ,Correct.
77. The lifting machinery user unit shall establish and improve the corresponding lifting machinery manufacturing safety management system. ,mistaken.
78. It is a prerequisite for normal production to ensure the correct use of hoisting machinery and to ensure safe operation and maintenance. It mainly includes process operating procedures and safe operating procedures. ,Correct.
79. Lifting machinery operators should strictly implement the operating procedures and relevant safety rules and regulations of lifting machinery during operations. ,Correct.
80. When operating personnel discover hidden accidents or other unsafe factors during the operation, they should immediately report to the relevant person in charge at the next higher level of the enterprise. ,Correct.
1. The scope of the definition of hoisting machinery is defined as a lift with a rated lifting capacity greater than or equal to (A, 0.5 tons,).
2. Hoisting machinery defines a crane with a rated lifting capacity greater than or equal to (B,, 1 ton) and a lifting height greater than or equal to two meters.
3. Hoisting machinery defines a crane with a rated lifting capacity greater than or equal to 1 ton and a lifting height greater than or equal to (C,, two meters).
4. The wire rope is made of high-quality steel wire twisted, and its motives are mostly used (B,, double-wound rope).
5. The steel wire rope (A, same direction twist) is not suitable for use on the lifting mechanism.
6. It is suitable for the occasion of rigid different track or the tension state is (B,, the same direction twist) steel wire rope.
7. The most widely used crane is (C,, alternate twist) wire rope.
8. (A,, point contact) The wire rope is generally not used in cranes with low strength and short life.
9. As long as the crane bypasses the pulley or winds into the drum, the wire rope (A,, line contact) should be used.
10. Repeated bending and straightening impacts of the wire rope on the drum or pulley will occur (A,, bending fatigue).
11. The main reason why steel wire rope is easily damaged when working in a high temperature environment (C, high temperature baking).
12. Especially the illegal lifting and pulling of buried objects, it is easy (B,, overload) to break the wire rope.
13. When the wire rope is used in a humid environment, a large number of pits will be formed in the back, which will damage the wire rope (A,, corrosion).
14. "Who is the practical code for inspection and scrapping of steel used in cranes" is implemented according to (C,, GB5972-2006).
15. The cross-sectional area of the steel wire rope decreases during wear and the strength decreases. When the outer steel wire wears to its diameter (A, 7%), it should be scrapped.
16. When the diameter of the wire rope is reduced (A,, 7%) or more relative to the nominal diameter, it shall be scrapped.
17. Hoisting machinery regulations shall not be used (A,, casting hook).
18. The shape of the crane hook mainly used for small and medium lifting capacity is (C,, single hook).
19. The material of the hook body can be fully utilized and the stress condition is good. It is commonly used on cranes with heavy lifting capacity (B,, Shuangditch).
20. The dangerous cross-sections of conventional hooks are (C,, three).
21. At the undercut groove of the hook thread, the section is subject to the greatest (A,, tensile stress).
22. The weight is the largest (C, shear stress) on the section of the hook through the action of the wire rope.
23. The crane hook is inspected every (B, half a year) and cleaned and lubricated.
24. The lifting hook should be returned every (A,, 2 years) to avoid fatigue and cracks.
25. The role of the fixed pulley in the crane pulley group is (C,, change the direction of the wire rope force).
26. The role of the movable pulley in the crane pulley group is (B,, labor saving).
27. In the bridge type crane, there is a spiral groove at each end of the reel, the direction of rotation (C, reverse)
28. When the hook or other retrieval device is placed in the lowest position, in order to prevent the wire rope head from being pulled out of the fixing device, remove the number of fixed wire tail coils, and there must be (B,, two to three turns) on the reel. Wire rope.
29. Lifting machinery adopts (A,, normally closed) brakes for luffing brakes.
30. Each hinge point of the brake should be lubricated every (C,, one week).
31. For brakes working in a high temperature environment, each hinge point should be lubricated every (C,, three days).
32. The oil of the hydraulic electromagnetic push rod release device needs to be replaced every (A,, half a year).
33. It is often in the closed state. When the mechanism is working, the external force is used to release the brake. This kind of brake is called (B,, normally closed)
34. It is often in the loose brake state. When the mechanism is working, the external force is used to make it close. This kind of brake is called (C,, normally open)
35. If you find that the temperature of the brake wheel is too high and the brake pads emit smoke, you should adjust the brake (A, the gap between the pad and the brake wheel) in time.
36. When the crane is running under the rated load, when the brake has a braking effect, it will continue to move for a certain distance under the action of inertia, and the free distance is called (C, brake stroke).
37. The surface of the brake wheel is contaminated and should not be cleaned with (B, engine oil).
38. The reducer used for the hoisting mechanism of a variety of cranes and the trolley running mechanism of bridge cranes is (B,, two-stage) gear transmission.
39. The reducer of the trolley running mechanism of bridge and gantry cranes and the trolley running mechanism of gantry cranes is (C,, three-stage) gear transmission.
40. The noise requirement of the reducer is not more than (B, 85 decibels)
41. The amount of oil in the reducer (C, moderate)
42. During the loading and unloading process, two independent drums drive the opening and closing rope and the support rope respectively. The most widely used one is (A,, double rope grab)
43. The special electromagnet for sucking and transporting steel and section steel should be equipped with a sound and light alarm device when the voltage is lower than the rated voltage of the electromagnet (A, 85%).
44. The most widely used motor on cranes is (C, winding type asynchronous)
45. Using a specific method to change the speed of the motor is called (B,, speed regulation)
46. The AC motor used to directly control the motion mechanism of small and medium cranes is the (A,, cam) controller.
47. The AC motor used to directly control the lifting mechanism of the small crane is the (C,, cam) controller.
48. The linkage console can simultaneously or separately control (B,, two) mechanism actions through the linkage mechanism.
49. The extensive use of overload limiter can effectively prevent (C,, overload) caused by rope breaking accidents.
50. When the load reaches the rated lifting capacity (C, 90%), an early warning signal should be issued.
51. When the load exceeds the rated load and is less than (C,, 110%) of the rated load, it should be able to automatically stop lifting and issue an alarm signal.
52. When the cart runs to the end point or when the two carts are close, the limit switch of the cart is activated by (A,, safety ruler).
53. The protective cover is a very important safety accessory on the crane. It can effectively prevent the operators and inspectors from being (C,, involved) hurting others.
54. Because of the open-air bridge crane, its rail clamps and anchoring devices should be able to withstand the maximum wind force under non-working conditions and not be blown.
55. When working in open air, bridge cranes must use anchoring devices when encountering conditions (C, or more than six winds).
56. When two adjacent cranes are about to collide, (A,, operation limiter) will take effect first.
57. The operation limiter is composed of (B,, safety ruler) and a travel switch.
58. Crane driving work in trial operation,! Should be operated by (C,, crane driver).
59. When the moving speed is greater than 120 meters per minute, the buffer should be adopted (C,, hydraulic).
60. The crane wheel walking on the rail should be installed in front of the wheel (B, rail sweeping plate)
61. The customary name of the stopper set at the end of the crane running track (A,, stop)
62. The height of the party building at the end of the crane running track should be higher than the height of the buffer of the crane trolley (C,, appropriate)
63. Cranes working in the open air need to be equipped with anti-skid devices to prevent being blown by strong winds. The rail clamps suitable for small cranes are (A,, manual)
64. Cranes working in the open air need to be equipped with anti-skid devices to prevent being blown by strong winds. The rail clamps suitable for large cranes are (B, hydraulic spring type)
65. When the power supply of the crane is a low-voltage system with a neutral point directly grounded, the metal structure or cart track should be protected by you (B,, zero protection)
66. In the low-voltage power supply system where the neutral point is directly grounded, one or more places on the neutral line are connected to the ground again through the grounding device as (C,, repeated grounding)
67. In the low-voltage power supply system where the neutral point is not grounded, the metal or cart track of the crane should be adopted (A,, grounding protection)
68. The grounding resistance at any point on the starter shall not be greater than (C, 4 ohms)
69. The power cord of the power switch should be led from the inlet end of the (B, main isolating switch) on the crane.
70. Lifting machinery is a category in the special equipment catalog, divided into (B,, twelve) categories.
71. Lifting machinery is a category in the special equipment catalog, divided into twelve categories (C, 83) varieties.
72. The span of the bridge crane refers to (A, the horizontal distance between the crane support centerline).
73. In the working speed of the mechanism, the unit of the lifting speed and the running speed of the cart or the trolley is (C, per decimeter).
74. In the working speed of the mechanism, the unit of rotation speed is (B,, revolution per minute)
75. Cranes, remember that the work level is divided into (C,, A1-A8)
76. The working level of the crane and its metal structure is determined by the working level of its (A,, main hoist) mechanism.
77. In the crane structure parameters, the lifting height is represented by (B,, H).
78. In the hoisting machinery parameters, the lifting moment is represented by (C,, M).
79. In the crane parameters, the gauge is represented by (A,, K).
80. In the hoisting machinery parameters, the width is represented by (B,, L).
81. The lifting machinery user should use the lifting machinery manufactured by the corresponding (B, licensed) unit.
82. Lifting machinery users should set up a lifting machinery (C,, safety management) organization to engage in the safety management of lifting machinery.
83. The lifting machinery user unit should be equipped with (A, full-time and part-time safety management) personnel to engage in the safety management of lifting machinery.
84. The lifting machinery user unit shall formulate the lifting machinery (A, emergency rescue plan for accidents) and conduct regular drills.
85. Hoisting machinery operators shall pass (B, Quality Supervision Department) examinations and obtain special equipment operators certificates in a unified national format before they can engage in corresponding operations.
1. Lifting machinery includes its accessories (A, safety accessories. B, safety protection devices. D, safety protection devices related facilities).
2. The steel wire rope core has (A, hemp core. B, cotton core. C, asbestos core. D, metal core).
3. The wire rope is divided into (B, surface contact. C, point contact. D, line contact) wire rope according to the contact state of the wires between adjacent layers in the strand.
4. The main reasons for wire rope damage are (A, bending fatigue. B, corrosion. C, high temperature baking. D, overload. E, deformation).
5. Forging hooks are usually forged from (B,, DG20. D,, DG34GrNiMo.) steel.
6. The plate hook is made of (A,, 16Mn. C,, Q345) steel plate, and multiple pieces are overlapped and riveted.
7. The hook shape is divided into (A, single hook. D, double hook.)
8. Single hook is mainly used for small and medium-sized cranes, with (B, long hook. C, short hook.)
9. According to whether the central axis of the pulley is moving, it can be divided into (A, movable pulley. B, fixed pulley.)
10. Pulleys are classified according to their materials (A, cast iron. B, cast steel. C, welding. D, nylon.)
11. The reel is used to wind the steel wire rope, there are (A, casting reel. D, welding reel).
12. The brakes commonly used on cranes are (A, short-stroke electromagnetic pad type. B, long-stroke electromagnetic pad type. C, hydraulic electromagnetic pad type. D, hydraulic push rod pad type.) brakes.
13. In the hoisting machinery, the reducer plays a role of (C, reduce the speed. D, increase the output torque.).
14. Grabs can be divided into (A, single rope grab. C, double rope grab. D, electric grab) according to their operating characteristics.
15. The main disadvantage of the electromagnetic chuck is (A, poor safety performance. C, greatly affected by temperature. D, greatly affected by manganese and nickel content).
16. The reason for the motor overheating is (A, the voltage is too low. B, the voltage is too high. D, the overload operation).
17. The reason for the overheating of the motor is (B, single-phase operation of the motor. C, changing the working system to operate. D, poor ventilation and cooling.)
18. Do a good job of motor maintenance and inspection (A, monitor whether the running sound is normal, whether the bearing is noisy. B, check for abnormal vibration, and whether the fastening screws are loose. C, keep it clean to prevent water droplets and iron filings Fall into the inside. D, check whether the temperature of each part exceeds the allowable value).
19. The working state of the crane motor is (A, electric. B, regenerative braking. C, reverse braking. D, one-way automatic.)
20. The protective box is composed of (A, knife switch. B, contactor. C, overcurrent relay) and so on.
21. The protection box is used to control and protect the crane to realize the motor (A, overcurrent protection. C, short circuit protection. D, loss of voltage, zero position, limit protection).
22. Hoisting machinery can be roughly divided into (A, light and small lifting equipment. B, bridge type cranes. D, boom type cranes.) basic types according to structural characteristics.
23. Bridge type crane, which is characterized by (A, lifting mechanism. D, large and small car operating mechanism).
24. The following crane classification does not belong to the boom crane category (B, gantry crane. D, beam crane).
25. The basic parameters of bridge type cranes are (A, rated lifting capacity. B, span. C, lifting height.)
26. The following cranes belong to the bridge type crane (A, gantry crane. B, beam crane. D, general bridge crane.) The basic type.
27. Gantry crane types are (A, rail-mounted container. B, quayside container. C, shipbuilding gantry. D, loading and unloading bridge) starter.
28. Lifting machinery users should conduct safety technical training for lifting machinery operators to ensure them (A, master operating skills. B, knowledge of accident prevention. D, enhance safety awareness).
29. The lifting machinery user unit shall carry out daily maintenance of the main lifting machinery (A, force-bearing components. B, safety accessories. C, safety protection devices. D, control system.), etc., and make records.
30. Lifting equipment users should be equipped with rigging and spreaders that meet safety requirements, and strengthen daily (A, safety inspection. B, maintenance.) to ensure the safe use of rigging and spreaders.
31. The crane user unit should conduct safety education for the operators and related personnel involved in the crane operation site, so that the operators have (A, corresponding safety knowledge. B, master the corresponding laws and regulations of the country. C, understand the knowledge of preventing crane accidents .D, improve safety awareness.)
Accident case 1
1. The accident:
An electric welder in a chemical industry zone was operating a five-ton single-beam electric hoist to lift the welded parts. Suddenly the welded parts rolled over and fell in midair, causing the employee to die on the spot.
2. Accident investigation:
The equipment has passed regular inspections and registered and is within the validity period. The safety device is effective. The auxiliary spreader (shelf) is hoisted with two wire ropes, one is hung on the hook and the other has fallen off. The welder has not been trained in lifting operations, and the electric welder has not been trained in lifting operations.
3. Analysis of the cause of the accident:
B: No relevant training for employees. C: No special spreader is used on the shelf. D: There is no manager on site to stop the risky operations.
Accident case 2
1. The accident:
Wu, a worker in a development zone, prepared the sandbox to close the mold after casting and turning. During the lifting and turning process, the chain on one side of the sandbox suddenly slipped, and one side was tilted directly on Wu's body. He was sent to a doctor and died.
2. Accident investigation:
The safety device of the equipment is effective and used within the safety inspection period. The sandbox hook reversal is performed by Wu, without external interference.
3. Analysis of the cause of the accident:
A: The hoisting chain is not installed firmly. C: Do not have safe operation skills. D: No knowledge of labor protection.
Accident case 3
1. The accident:
In the building materials market, a few children were playing next to a working 5t/20t gantry crane. Suddenly someone shouted for help. He saw a child lying next to the cart track with blood on his hands. He was sent to the hospital immediately. fracture.
2. Accident investigation:
The safety device of the equipment is effective. The distance between the rail sweeping plate of the crane and the rail is 45 mm, and the driver holds a valid certificate to work.
3. Analysis of the cause of the accident:
A: The safety management of the premises is lacking. B: The driver's operation is not standardized, and there are behaviors that ignore safety. C: The equipment has potential safety hazards.
Accident case 4
1. The accident:
In the warehouse of the material company, a three-ton electric single-beam crane was hoisting goods. Suddenly the wire rope guide on the electric hoist fell off. A worker working on the ground was found, with blood flowing from his head and serious injuries to the doctor.
2. Accident investigation:
The hook pulley shell is deformed seriously, the thread of the rope guide fastening screw is obviously worn, the safety device is effective, and it has passed the safety inspection and used within the validity period.
3. Analysis of the cause of the accident:
A: The fixing screws of the rope guide are loose. B: You, the maintenance is not in place and there is a lack of daily inspections. C: There is an illegal operation of oblique pulling and oblique crane during use. D: The company's safety responsibility system has not been implemented.
Accident case 5
1. The accident:
One night, in a wharf, when a crane operator was grabbing stones, worker Luo walked from the ship. The operator did not know that he had entered. The grab hit Luo's back and died in hospital.
2. Accident investigation:
The grab passed the regular inspection and was used within the validity period. The inspection did not find any equipment defects related to the accident. The operator was on duty with a certificate and no illegal operation was found.
3. Analysis of the cause of the accident:
A: Lack of on-site safety management. C: There is no adequate lighting on the job site.
Incident case 6
1. The accident:
Wang Mou, a steel plant worker, drove a 10-ton double girder bridge crane without permission because the crane driver was resting. Due to the failure of the ascending stopper, the hook hit the top, the wire rope broke, and the hoisted object fell along with the hook. , Smashed Liu, a maintenance worker below, and died on the spot.
2. Accident investigation:
The ascending limiter is removed, the brake of the lifting mechanism is incomplete, the gear controller handle lacks a hand wheel, the operating brake of the large and small vehicles is removed, and the operating limits of the large and small vehicles are invalid.
3. Analysis of the cause of the accident:
B: The safety management is not strict and the operation is unlicensed. C: The equipment is running out of control with illness. D: There is no record of regular inspection, usage, maintenance, etc.
Accident case 7
1. The accident:
In a food company, a 25-ton truck crane on a plant site under construction, the crane boom collapsed the site scaffolding, causing serious injuries to many workers.
2. Accident investigation:
The car crane cocked, two of the six hydraulic fixing brackets were broken, one of the three-ton steel beams fell to the ground, and the boom fell to one side.
3. Analysis of the cause of the accident:
C: The operating radius exceeds the regulations, and the overload rolls over. D: There are no operating regulations for the outriggers of the truck crane.
Incident case 8
1. The accident:
A 10-ton bridge crane was installed in Mou Mould Co., Ltd. When two truck cranes were hoisting the main girder at the same time, the lashing wire rope suddenly broke, causing it to fall to the ground, causing serious bending and deformation of the main girder. Fortunately, no casualties were caused.
2. Accident investigation:
The two truck cranes are both carried out by the company according to the small advertisement posted on the side of the road. The rental crane unit does not have the qualification to lift the starter, and the driver does not have the operation certificate.
3. Analysis of the cause of the accident:
A: Wrong binding of wire rope. B: Mistakes in hoisting command. C: Violation of Special Equipment Safety Supervision Regulations, Article 17.
Incident case 9
1. The accident:
In a machinery factory, the drivers Chen and Li were going to enter the cab of a 20-ton electromagnet crane in the afternoon. They found that the crane had slipped on the stair platform and could not enter. So Li climbed onto the top platform to enter the cab, turned on the switch, and the starter did not move (the power could not be sent). Li closed the passage railing door, and did not park on the cab platform accurately after starting. Chen was about to board the car with his neck clamped between the column and the cab shell and died on the spot.
2. Accident investigation:
The positioning of the operating mechanism of the lifting trolley of the equipment is correct, and the braking is effective. The safety devices are complete and complete, the working mechanism is effective, the brake friction lining of the cart brakes unilaterally touches the brake slack, the electric interlocking protection, the zero protection is reliable, and the braking distance of the medium-speed (41 meters per minute) cart is about seven meters.
3. Analysis of the cause of the accident:
B: Improper adjustment of the truck brake. D: The driver lacks safety awareness.
Incident case 10
1. The accident:
A 14-ton ship unloader at the dock of Mou Transportation Company, controlled by PLC semi-automatic or manual grab ship unloader, was working. Two hoisting operators were working on the ship. Suddenly the grab came towards them and was hit by the grab. , Causing one death and one injury.
2. Accident investigation:
The equipment was used within the validity period, and the electrical and control system did not find complete hydraulic system equipment, and the console lever was not blocked, and it was in line with the direction of movement, but some indicator buttons did not light up.
3. Analysis of the cause of the accident:
B: There are behaviors that ignore safety. C: The driver's operation is not standardized.
Incident case 11
1. The accident:
A 10/40t gantry hook crane on the return site of a storage and transportation company is hoisting plates. The driver first puts the main hook away while lowering the auxiliary hook. The hook is about to hang the plate, and suddenly the main hook falls and hits it. The head of the hooker died on the spot.
2. Accident investigation:
The equipment has passed regular inspections, and the on-site investigation of the ascending stopper has been damaged (before the accident). It is also learned that the main hook was quickly raised when the auxiliary hook was quickly lowered before the accident.
3. Analysis of the cause of the accident:
A: The ascending limiter is out of order. B: Violation of operating regulations (two sets of lifts cannot be operated at the same time). D: Lack of maintenance and loose management in daily use.
Incident case 12
1. The accident:
In an equipment repair factory, Niu used a steel wire rope to tie up the repaired equipment, and used a five-ton electric hoist to hoist it to an overhaul platform. When hoisting to the third platform, the steel rope broke and the hanging object was pressed on Liu, causing a fracture of the femur of the left leg. The injury was serious and the left leg could not be saved.
2. Accident investigation:
The electric hoist has a product qualification certificate from the manufacturer, but the user did not apply for security inspection or register for use until the hoist was installed and put into use until the incident.
3. Analysis of the cause of the accident:
A: The unit uses cranes without a license. B: The binding method is wrong. D: The operator has no relevant safety knowledge and skill training.
Incident case 13
1. The accident:
In the workshop of an equipment company, a 5/20t bridge crane is hoisting a "low temperature heater" shell (weight 12.9 tons). During the hoisting process, the wire rope suddenly broke and the material fell. Working cold on Gu's head underneath, he was sent to a doctor and died due to serious injuries.
2. Accident investigation:
The crane is used by the postal service, and the driver holds a certificate to work. The lifting process is smooth and there is no abnormality. The position of the shell steel rope is wrong, the binding method is wrong, and the single steel rope is connected with the hook.
3. Analysis of the cause of the accident:
B: Crane hook work is not standardized. C: The hoisting commander made a mistake.
Incident case 14
1. The accident:
In a foreign trade refrigeration equipment assembly workshop, foreign personnel operated a 15-ton crane to lift a refrigeration unit. The unit fell to the ground due to the lifting of the hook and the broken steel rope. Fortunately, there were no casualties, but the economic loss was large.
2. Accident investigation:
The equipment has passed the inspection of installation and acceptance. The broken rope at the fixed end of the reel is broken into an overload fracture shape. The protective cover of the reel has obvious traces of being hit by the hanging ditch. The electrical device of the height limiter has been tested and effective.
3. Analysis of the cause of the accident:
A: Foreign personnel violated regulations. C: The height limiter triggers the displacement of the stopper. D: The trigger block is loose and not repaired to the normal position in time.
Incident case 15
1. The accident:
At a container terminal in a port, a portal crane in use suddenly fell while loading and unloading a container. Fortunately, there were no people on the scene.
2. Accident investigation:
The equipment has only been used for more than seven months, and the high-speed shaft of the gearbox of the hoisting mechanism broke and some of the teeth of the gear teeth broke.
3. Analysis of the cause of the accident:
A: The equipment manufacturer did not strictly implement the process requirements. B: Stress concentration at the rounded corners of the shaft shoulder. D: The supervisory inspection of the crane manufacturing process is not implemented.
Incident case 16
1. The accident:
In a steel structure factory, worker Zhou used a crane rated at 50 tons to transport a steel plate weighing 1.5 tons. During the lowering process, the binding wire rope fell off the hook, and the steel plate fell to the side, holding down the polishing process. The working worker died due to ineffective rescue.
2. Accident investigation:
The hook has no safety device, and the hook speed has been worn out, and the amount of wear is greater than 15%. The accident crane was moved and reconstructed privately. The span was increased from 16.5 meters to 18 meters. The relevant procedures were not completed, the inspection was not declared, and the operation limit was invalid, etc. Defect, Zhou does not have a lifting operator certificate.
3. Analysis of the cause of the accident:
A: The hook has no anti-decoupling device. C: The unit's safety management is chaotic moving and refitting cranes. D: Unlicensed personnel operating the crane caused operational errors.
Incident case 17
1. The accident:
In a steel plant, three crane maintenance personnel were working in the maintenance channel on the crane rail. At this time, the crane on the track did not stop when it reached the maintenance platform and hit the head of one of the maintenance personnel, causing death on the spot.
2. Accident investigation:
The crane is inspected regularly and used within the specified period, the relevant safety devices are effective, the operating brake function meets the requirements, and there is no abnormal situation. There is a dedicated maintenance channel on the outside of the crane track, but no maintenance signs and guardrails are seen.
3. Analysis of the cause of the accident:
B: The crane driver operates blindly. C: Repair work and production work overlap. D: There is no safety sign reminder.
Incident case 18
1. The accident:
A maintenance worker in a hoisting machinery factory was repairing a double-girder crane in an equipment container factory. A maintenance worker on the lifting trolley mechanism was hung his coat by the fixed steel strip protruding from the coupling, and his body was twisted into the equipment and the trolley Inter-agency,
2. Accident investigation:
The crane is used in each cycle. Among the three maintenance personnel, two of them have no operator certificates, and the injured are certified personnel. The safety shield is removed, and the coupling of the lifting mechanism is made of a long steel bar. Fixed, all safety devices are effective, operating handles and signals are effective.
3. Analysis of the cause of the accident:
A: Did not notice the risk of exposed steel bars. B: The user has no safety supervision on the maintenance personnel who come to the factory. C: Undocumented personnel are on duty.
Incident Case 19
1. The accident:
In the company's material preparation workshop, an electrician was climbing from the workshop format steel frame to the crane overhaul platform. He was squeezed by the running crane in the steel frame column and the crane wheel protection suite, and fell to the ground to death.
2. Accident investigation:
During the validity period of the inspection, the equipment crane has a special repair channel ladder against the wall, and the crane has no defects related to the accident.
3. Analysis of the cause of the accident:
A: The electrician violated the operating regulations. C: No on-site safety alert and safety supervision. D: The safety management system is not strict and the safety education is not deep.
Incident case 20
1. The accident:
In the concrete yard of a company, the wire rope suddenly broke when the hopper hoisted by an electric hoist gantry crane was moving, causing the hopper to fall and tip over, overwhelming the workers who were working nearby to death.
2. Accident investigation:
It is a transfer equipment, has not been registered, the operator is operating without a license, the rope guide is missing on the hoist drum, there are obvious new signs of collision at the bottom of the shell, the hook assembly has fallen off, and there are signs of impact personnel under the hopper.
3. Analysis of the cause of the accident:
A: The crane is used without inspection, without registration, and defective. B: The rope guide is missing. C: The operator does not have a license to operate, and does not have basic common sense of operation. D: The hook lifting limit device loses its limit function.
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