About the “Ten Don’ts” when using tower cranes. Things to note when using tower cranes
Tower cranes are used as vertical cranes in construction operations. Transport machinery is widely used and has become an indispensable construction machinery in construction. As a large-scale construction machinery, it has the following characteristics from a safety perspective:
1. It usually has a huge structure and a relatively complex mechanism, and can complete one lifting movement and one or several horizontal movements.
2. There are various types of heavy objects being lifted, and the loads vary.
3. It needs to operate directly within a larger range and has a larger space for activities.
4. There are many exposed and moving parts, and they are often in direct contact with lifting operators (such as hooks, wire ropes, etc.), which may lead to many accidental risk factors.
5. The operating environment is complex.
6. Work often requires the cooperation of multiple people to complete an operation together.
The existence of many of the above-mentioned dangerous factors determines that there are more lifting injury accidents. Once a tower crane accident occurs, not only property losses but also personal injuries will be caused in most cases, which will have a greater impact. Therefore, it has been classified as Into the management of special equipment, relevant specifications and procedures have been issued for its manufacturing, installation, use and maintenance. The relevant departments or units have summarized the dangers in the operation and have summarized the “Ten Do Not Lift” regulations for lifting operations. As long as By adhering to this “ten don’t hang” principle, tower crane accidents can be avoided to the greatest extent. However, in actual production, there is currently no scientific, specific and practical version of the “ten things that should not be lifted” in the industry, and there are no special provisions in the relevant specifications of tower cranes. This article attempts to analyze and summarize the various versions and specifications of tower cranes in our country, and on this basis, puts forward specific regulations on the “ten don’ts” of tower cranes for your reference.
Now the relevant “ten things not to worry about” circulating in our area are listed as follows:
1. ” The “Ten Don’ts of Lifting” listed in the book “Construction Site Safety Management System”:
1. Do not lift if there are people staying or walking under the lifting arm and the lifting weight.
2. The lifting command should be provided by full-time personnel with qualified technical training. No lifting is allowed without command or the signal is unclear.
3. Slender materials and multiple objects such as steel bars, steel sections, pipes, etc. must be bundled securely. They are not allowed to be lifted with a single head weighing a thousand pounds or if the bundling is not firm.
4. It is not allowed to lift porous plates, hoppers, and hand-operated bucket trucks when they do not use four points or when large formwork external panels do not require an armor-removing crane. Precast reinforced concrete floor slabs are not allowed to be double-assembled.
5. Safe and reliable block fixtures must be used for hanging bricks. Brick cages must be used for hanging bricks and they must be stacked neatly. Scattered objects such as wooden bricks and embedded parts must be stacked securely in containers and not stacked properly. No one is allowed to hang.
6. No one is allowed to lift suspended objects such as floor slabs and girders.
7. Sheet piles, well point pipes, etc. buried in the ground as well as adhering or attached objects are not allowed to be lifted.
8. When working with multiple machines, the distance for lifting heavy objects should be ensured to be no less than 3m. When working with multiple machines on the same track, no lifting is allowed without safety measures.
9. No hoisting is allowed in strong winds above Level 6.
10. It is not allowed to hang heavy objects at an angle or exceed the allowable load of the machine.
The first of the above, “Do not lift if there are people staying or walking under the boom.” This is definitely unavoidable at the construction site, because when the tower crane is rotating, the hoisted objects are almost Covering the entire site, there will definitely be people staying or walking under the boom; “People are not allowed to hang under the lifted heavy objects if they are staying or walking under them” is already contradictory. It is required not to lift the heavy objects after they have already been lifted, so this clause does not make much sense. . In the fourth article, the hopper is probably a special hopper equipped with the tower crane, which must be hoisted at four points. However, hand-overturned bucket trucks are probably prohibited from being used to lift materials, so this article should also be revised; the remaining articles only It explains some particularities, but not completely.
2. The “Ten Things Not to Hang” on tower cranes in the “Migrant Workers’ Night School Reader” published by the Chengdu Safety Supervision and Management Station
1. Overloading and tilting Can’t pull or hang.
2. Bulk items are not allowed to be lifted if they are too full or are not tied firmly.
3. No command, random command and unclear command signals.
4. Do not lift objects with sharp edges without protective measures.
5. People standing on the hanging objects and stacking scattered objects do not hang them.
6. No lifting of components buried underground is allowed.
7. Do not lift if the safety device fails.
8. It is not allowed to lift objects in foggy weather or dark light if the hanging objects cannot be seen clearly.
9. Do not hang under high-voltage lines or too close to high-voltage lines.
10. Do not hoist in strong winds above Level 6.
There are no requirements for small objects such as bricks, stirrups, etc. in the above. The foggy days in Article 8 and Article 10 are both “bad weather” of the same nature, so they need to be supplemented and improved.
3. The “Ten Things Not to Hang” for tower cranes in the training material “Construction Site Safety Production Management System” issued by the Sichuan Provincial Work Safety Administration:
1. Do not lift when overloaded.
2. Do not lift if the command signal, light, or weight are unclear.
3. The slings and accessories are not tied tightly and do not meet safety requirements.
4. Pull or hang things crookedly or do not hang objects buried underground.
5. The safety device does not work well.
6. Do not lift when close to high-voltage lines and without reliable safety measures.
7. Do not hang objects when there are people standing on them or moving objects on them.
8. Do not lift flammable and explosive materials.
9. Objects with sharp edges and corners are not properly padded or hung.
10. Do not hang up when using or commanding in violation of regulations.
There are also no requirements for small objects in the above, but bad weather is only mentioned in the first article.The word “unclear light” is not perfect. The “flammable and explosive materials” in Article 8 are more general. For example, wood, foam, etc. in the construction site are all flammable and explosive materials, so they must be hoisted. If there are oxygen and acetylene bottles on the 20th or 30th floor during the main construction, if they are not hoisted up by a tower crane, can they be lifted up by people? This is also debatable. The item “illegal use” in Article 10 is relatively general. It is very important to point out what is illegal use, so this article is included.
4. “No lifting” (or items prohibited from operation) in the corresponding specifications of tower cranes:
1. “Safe technical operation of construction machinery” Regulations” (JGJ33-2001) requires Article 4.4.40: If strong winds or gusts of level 6 or above are encountered during operations, operations should be stopped immediately;
2. “Tower Crane Operation Regulations” (JT /T100-1999) requires that the driver shall not operate the crane if one of the following conditions occurs during operation:
(1) The command signal cannot be clearly distinguished;
(2), command that will cause accidents;
(3), command that does not meet the performance of the crane.
3. Article 3.1.11: When there are two or more commanders in operation, the operation can only be carried out when only one commander sends a signal. No operation is allowed when two or more commanders send signals at the same time.
4. Article 5.2.1: The driver must be familiar with the performance of the crane he is operating, and should operate in strict accordance with the instructions. He is not allowed to pull heavy objects diagonally, bury them underground, or stick them to one another. Heavy objects on the ground, on equipment, and objects of unknown weight.
5. Article 5.2.6: The driver shall not operate a crane with invalid, missing or inaccurate safety devices.
6. Article 5.2.8: Cranes are not allowed to be overloaded or operate under wind conditions.
7. Article 5.2.13: It is not allowed to lift heavy objects of people, and it is prohibited to use cranes to lift people.
Article 8. 5.2.16: Operations should be stopped when encountering the following conditions during operation:
(1) Severe weather, such as heavy rain, strong wind, heavy fog, exceeding the allowable working wind, etc. Operations that affect safety;
(2) Electricity leakage occurs in the crane;
(3) The wire rope is severely worn, twisted, broken, knotted or out of the groove;
(4), the safety protection device fails;
(5), abnormal phenomena and noises occur in each transmission mechanism;
(6), the metal structure part is deformed ;
(7) The crane has other malfunctions that hinder operations and affect safety.
According to the above, the first article refers to bad weather; the second and third articles refer to the command signal; the fourth article refers to the lifting capacity; the fifth article refers to the safety device; Article 6 refers to lifting weight and weather conditions; Article 7 refers toNo passengers are allowed; the first item in Article 8 refers to the weather, and the following items refer to safety devices.
5. Based on the above analysis, the author summarizes the “Ten Things Not to Hang”:
1. Do not hang heavy objects crookedly or diagonally.
2. Do not lift if the rated load of the crane is exceeded.
3. Do not lift heavy objects buried underground or adhered to the ground or equipment, as well as heavy objects of unknown weight.
4. No command, random command and unclear command signals.
5. Small items are not installed in hanging cages (blue) or are not installed flatly, or are not hung beyond the edge of the hanging basket.
6. Do not lift the hoisted object when there are people standing on it or moving objects on it.
7. Lifting objects and accessories are not tied firmly or do not meet safety requirements.
8. Do not lift objects with sharp edges or corners without protective measures.
9. The safety device fails and the crane cannot be lifted.
10. Do not pay attention to severe weather such as heavy rain, heavy snow, heavy fog, or strong winds above level 6.
The above are the “ten things not to be afraid of” summarized by the author based on various versions and related specifications. If there are any shortcomings, please criticize and point out, learn from each other, or discuss together through the suggestions of this article, so as to make the tower crane more practical. The “Ten Don’ts” formed a normative document.
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