1. Overload operation is very harmful to the crane structure. The typical example is caused by the main beam deflection, cracking and welding of the upper cover plate and web, which brings serious accidents to the crane's safe operation. As the main beam deflects, the trolley track will deform along with the main beam. When the car drives from mid-span to both ends, it must not only overcome the normal running resistance, but also overcome the additional resistance caused by climbing. In severe cases, the motor of the trolley running mechanism is burned.
2. Excessive stresses caused by overloading cranes can cause wire ropes to break, damage transmission components, and burn out motors. Due to insufficient braking force, the brakes cannot hold the brakes and cause major accidents.
3. Overloading operations are more harmful to jib cranes, and often result in major accidents in which the jib and tower are broken. Overloading destroys the stability of the crane and can also cause malignant accidents of overturning of the whole machine.
4. Overloading operation will also cause the car to "slip", and it will slip by itself, which will seriously affect the lifting operation. For the double beam crane, it will also cause the "three legs" of the trolley to run, and due to the horizontal side bending, it will also cause a "gnaw rail" phenomenon during small operation.