Why Are Cable-stayed And Inclined Suspensions Not Allowed?

Why Are Cable-stayed And Inclined Suspensions Not Allowed?

The ten do not lift cranes are the operating rules that must be strictly followed in the operation of 25 ton overhead cranes. The ten do not lift regulations stipulate that crane operators are not allowed to perform cable-stayed and slanted hoisting, that is, the lifting wire rope must pass through the center of gravity of the hoisted object and keep it vertical, that is, it is not allowed to pull and slant hanging.

Why are cable-stayed and inclined suspensions not allowed?

1. Inclined cranes may be overloaded

Suppose you want to lift an object with a weight Q from the ground and lift it vertically, as long as the tension S of the wire rope is equal to Q or slightly greater than Q, the heavy object can leave the ground.

But if it is pulled obliquely, the wire rope will form an 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.

At the same time, F increases with the increase of the included angle. That is to say, the greater the angle when hanging obliquely, the greater the force on the wire rope when lifting the same heavy object.

Therefore, if a heavy object is hoisted vertically with full load, it will inevitably be overloaded when it is hoisted obliquely, and even an accident that the wire rope will be broken may occur.

2. Inclined hanging produces inertial force, which endangers surrounding personnel
 

In addition, the horizontal component force F generated when the weight is suspended 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 accidents by colliding with the hanger, surrounding workers or other objects.

In short, if it is hung obliquely, it will not only cause overload to break the wire rope, but also cause heavy objects to swing and collide with objects and people, thus causing personal and equipment accidents.