Be Vigilant! The Hazards Of Crooked And Inclined Cranes
May 22, 2023
Be vigilant! The hazards of crooked and inclined cranes
When operating a 5 ton single-girder crane, it is absolutely forbidden to lift the crane crookedly, because the crane may be overloaded, generate inertial force, and endanger the surrounding personnel.
Inclined lifting of cranes is a kind of illegal operation with the most accidents of cranes. The following is a detailed analysis of why cranes are strictly forbidden to pull and lift obliquely.
There are two situations in the lifting process:
1. The gravity of the hoisted object is less than the decomposition force of the hoisting machinery in the opposite direction of the gravity of the hoisted object, so the hoisted object will be lifted quickly due to the lifting force when it is lifted off the ground.
The decomposition force of the heavy machinery pointing to the force of the hoisting machinery in the horizontal direction of the hoisted object, with the top of the boom as a circle, the length of the wire rope as the radius, and the line passing through the top of the boom and perpendicular to the ground as The center line changes and accelerates to swing, endangering the safety of the hoisting machinery, operators and objects to be hoisted.
Simply put, if it can be hoisted, the thing to be hoisted will be thrown over and hit the crane and the operator.
2. On the contrary, if the gravity of the hoisted object is greater than the decomposition force of the force of the hoisting machinery in the opposite direction of the gravity of the hoisted object, the hoisting machinery will be pulled towards the hoisted object due to the retraction of its own wire rope, and dumping will occur.
Simply put, if it cannot be hoisted, the crane will pull itself.
Hazards of inclined crane
1. The inclined crane may be overloaded:
If the crane is pulled obliquely, the wire rope will form a certain angle with the vertical line of the ground.
According to the principle of mechanics, the pulling force s acting on the wire rope can be decomposed into the force P that makes the object vertically upward and the force F that moves the object horizontally. To make the object lift off the ground, P must be at least equal to Q.
However, F increases as the included angle increases. That is to say, the greater the angle of the crane when it is tilted, the greater the tension on the wire rope when lifting objects, and the accident that the wire rope may be broken may occur.
2. The inertial force generated by the tilted and inclined crane will endanger the surrounding personnel:
In addition, the horizontal component force F generated when the crane is inclined is also affected by friction before the weight leaves the ground. The moment it leaves the ground, the object will swing to the vertical center, which may cause certain accidents due to collision with the hanger, surrounding workers or other objects.
Not only will it cause overloading to break the crane wire rope, but it will also cause heavy objects to swing and collide with objects and people, thereby causing accidents in lifting machinery and equipment.
3. It will cause damage to the metal structure of the crane.
The horizontal rigidity of the 5 ton bridge crane is not as good as that of the double-girder crane. If heavy objects are hoisted obliquely, the horizontal component force will act on the main girder, which will inevitably cause the horizontal displacement of the main girder to exceed the tolerance, and form horizontal vibration after lifting. Seriously threaten the service life of the crane. If the heavy object is not in the middle of the main beam span, the deformation at both ends will be inconsistent, and even cause the crane to derail.
After reading the above explanations, I believe that everyone has already understood the hazards of the crane's crooked and inclined crane. I hope that customers must strictly follow the rules of use when using the crane, so as to produce safely and prolong the service life of the crane.
