20 Lifting Safety Questions

20 Lifting Safety Questions

 

(1) Dangerous positions During the lifting operation, some positions are very dangerous, such as under the boom, under the hanging object, the area before the hoisting object is hoisted, the triangle area of the guide pulley wire rope, the cable-stayed hook or the force direction of the guide pulley Wait, if you are in these positions, it is extremely difficult to escape in case of danger. Therefore, the position of lifting operators is very important. Not only should they pay attention to themselves at all times, but they also need to remind each other to prevent accidents.

 

(2) The safety factor of the sling is small. In the lifting operation, the safety factor of the sling is misunderstood, and the selection is often based on continuous use, resulting in overweight operations and a dangerous state.

 

(3) Lack of foreseeable factors in the operation. Due to various reasons, such as inaccurate weight estimation of objects, incomplete cutting, many pulling objects, the demolition parts are squeezed to increase the load, and the connection parts are not found to be forcibly lifted, etc., resulting in cranes, slings, etc. Accidents caused by sudden loading.

 

(4) Misuse of lifting operations involves a large area, and different units and different types of cranes are often used. Cranes have different daily operating habits and different performances, coupled with the influence of differences in command signals, accidents such as misoperation are prone to occur.

 

(5) When the binding is not firm, the measure of "locking" is not adopted for the suspended object during high-altitude hoisting and dismantling, but the method of "pocket" is used; the measure of "pad" is not adopted for the sharp edges and corners of the suspended object, and the bundled materials are hung vertically. The delivery is not tied firmly, so that once the hanging object vibrates in the ground, it will become unstable and fall or "draw lots" once it is scratched.

 

(6) The winding rope of the drum is not tight enough to hoist and dismantle large pieces, and the steel ropes wound on the drum of the crane or motorized winch are arranged loosely, so that the fast rope under heavy load is pulled into the rope bundle, causing the fast rope to vibrate violently and easily lose stability. As a result, there are often embarrassing situations where it is dangerous to continue to work, and it is impossible to stop

 

 

(7) Welding of temporary hanging nose is not firm

 

① Welding strength of temporary hanging nose is not enough.

The welding strength mentioned here is not enough, which means that the surface of the welding base metal is rusted, and the rust spots are not completely removed before welding, resulting in a beautiful and rich appearance of the welding meat, but the actual welding meat and the base metal are not melted together at all, and the load increases or is affected. impact, it breaks.

 

② The force direction of the suspended nose changes.

When hanging or laying down a long cylindrical object, as the angle of the object changes, the force direction of the hanging nose is also changing, and this situation is not considered enough in the design and welding of the hanging nose, resulting in defective hanging noses Sudden breaking (book breaking) during lifting operations. In such cases, it is necessary to weld the vertical plates on both sides of the suspension nose in advance, and the size and thickness of the vertical plates are best designed by professional technicians.

 

③ Nose welding material does not match the base metal and informal welder welding.

 

(8) Improper selection of hoisting tools or lifting points There is no theoretical calculation for setting up hoisting tools or using pipes, structures, etc. destabilized, causing the whole to collapse.

 

(9) Unreasonable selection of pulleys and ropes When setting up lifting tools, there is insufficient understanding of the force change of the pulley and the rope tied to the pulley due to the change in the angle between the ropes, the tonnage of the guide pulley is too small, and the rope used to tie the pulley is too thin , After the force is overloaded, the rope breaks and the wheel flies.

 

(10) Accidentally hanging objects with no-load slings There are many accidents that happen in this way. The lifting work has been completed. If the driver or commander of the operation does not respond in time to the suspended objects or other objects, an accident will happen in an instant, and this type of accident will have very bad consequences for the operators and lifting equipment.

 

(11) The disconnection between the hoisting plan and the actual operation is mainly due to the incomplete content, the lack of necessary data or the method does not match the actual operation situation, so that the operation plan becomes a shield to cope with the inspection by the superior, and does not play a role in guiding the construction.

 

(12) The suspended objects in the air have not been sealed with safety ropes for a long time. Due to the requirements of the installation process, some equipment or components need to be suspended in the air before being fixed in place, and some suspended objects stay in the air for a long time. If Without a safety safety rope, once the accidental vibration, impact or welding handle wire is injured, it will cause serious consequences for the suspended object to fall

 

 

(13) The process handover is unclear. If some structures or platforms are dismantled in the first shift but the handover after work is not clear, whether the shed built by Zhang San can be used by Wang Wu does not know. Unit A cut off the platform beam and Unit B continued to put heavy weights on the platform objects, so as to cause temporary support overload and collapse, etc.

 

(14) Insufficient understanding of the work site. The 20 ton overhead crane station site did not conduct underground consultation; the hidden dangers such as high-voltage lines, operating equipment, and coal-oxygen pipeline leakage points in the surrounding environment were not clearly understood before the operation; safety warning signs were not found in time, which led to accidents .

 

(15) Use a "defective" sling Some people just use a rope buckle to save trouble, but they don't know that it is a discarded rope buckle thrown by others. Electric welding has been done, and these defects and problems are not easy to check out; some unqualified spreaders such as pulleys and rings produced by informal manufacturers are used.

 

(16) Use hemp rope as a safety rope. Because the load-bearing performance of hemp rope is far inferior to that of steel rope, and hemp rope is easily damaged in daily storage and use, which will reduce the tensile force, so use hemp rope as a safety rope. If it does not have a safety effect, it will cause people to have psychological dependence and cause accidents.

 

(17) There is no warning area for large-scale hoisting and high-altitude operations in the dangerous area below. The safety warning area is not set up in time and safety guardians are not arranged, causing accidents to occur when others enter the dangerous area without knowing the situation.

 

(18) The weight of an object is inaccurate when two vehicles lift and flip an item. Since the center of gravity is changing during the flip, if the calculation is inaccurate, it is particularly easy to cause problems with one of the cranes being overloaded and unstable. If problems occur in this regard, they will not only threaten people security, and the economic loss is huge, and there are profound lessons in history, which need to be paid enough attention.

 

 

(19) Failure to take necessary preventive measures for operations in dangerous areas, such as working on the crane girder, contacting the driver of the crane in advance for insufficient confirmation, or due to misoperation by the driver of the crane while he was busy, because he did not take warning flags, warning lights, and equipment Measures such as car blocks, when the car suddenly appeared in the sky, other personnel could not escape in time to cause an accident.

 

(20) Reliable sealing measures have not been taken for lifting equipment such as gantry cranes that have not been installed in the open air due to insufficient consideration of climate impacts, and the hooks of tower cranes suspended in use have not been lifted to a safe position or anchored on lighter weights, etc. A gust of wind may cause accidents, and sometimes a sudden gust of wind and rain short-circuits the power supply, and it is too late to lift the hook. Therefore, it is very important to develop good work habits.

 

To sum up, the lifting operation involves various factors such as operation design, plan formulation, equipment selection, personnel operation, experience and skills, cooperation and mutual protection, multi-work cooperation, environmental characteristics and climate, etc. Therefore, it is necessary to do a good job in lifting The safety work in the operation requires great attention from all aspects of management personnel to operators, and strictly follows scientific laws.