Common types and causes of crane loss accidents

Crane loss accidents refer to accidents in which heavy objects such as hoisting loads and spreaders fall from the air and equipment damage during lifting operations. Loss accidents are relatively common among the equipment accidents, and they are also more serious. Next, the editor introduces the main types of equipment loss accidents and the causes of the accidents. Let's take a look!

  1. Detachment accident:

  Rope-off accident refers to a casualty and destruction accident caused by heavy objects falling off the tied hoisting ropes and collapsed. The main reason for the detachment accident is the improper binding method and essentials of the heavy objects, causing the heavy objects to slip; improper selection of the lifting center of gravity, resulting in partial load lifting or the instability of the lifting center causing the heavy objects to fall off; the lifting is subjected to collisions, impacts, Unsteady due to vibration, etc., causing heavy objects to fall.

  2. Decoupling accident:

  Unhooking accident refers to the accident of heavy objects falling out caused by heavy objects, hoisting ropes or special spreaders coming out of the hook mouth. The main reasons for unhooking accidents are the lack of hook protection device on the crane hook; the function of the hook protection device is invalid; the improper hoisting method and the deformation of the hook mouth of the hook cause the opening to be too large.

  3. Rope broken accident:

The main reasons for the breaking of the hoisting rope are mostly overloaded lifting and breaking the wire rope; the failure of the lifting limit switch causes the wire rope to be broken by the over-winding; the oblique crane and the diagonal pulling cause the chaotic rope to crush and cut the wire rope; the wire rope lacks maintenance due to long-term use Breaking accidents caused by fatigue deformation, wear damage, etc. that meet or exceed the scrap standard and still use.

The main reason for the breaking of the hoisting rope is that the hoisting angle is too large> 120 degrees, which causes the hoisting rope's tensile strength to exceed the value and break; the hoisting wire rope is not properly selected, or the wire rope that has reached the scrap standard is still used to bind and hoist heavy objects. The hoisting rope is broken; there are no protective measures such as gaskets at the contact between the hoisting rope and the heavy object, which causes the edges and corners to cut the wire rope and the hoisting rope breaks accident.

  4. Hook breaking accident:

  Hook breaking accident refers to the accident of heavy objects falling caused by the breaking of the hook. The cause of the breaking accident of the hook is mostly due to the defective material of the hook. The hook is still in use or is often overloaded due to long-term wear and tear, and the section has reduced and reached the scrap standard, causing fatigue damage and even fracture damage.

Crane loss accidents mainly occur in the winding system of the hoisting mechanism. In addition to detachment, disconnection, rope breakage and broken hooks, the fixing of both ends of each hoisting wire rope is also very important, such as the safety ring of the wire rope on the reel. Is it possible to ensure that more than 2 laps, whether there is descent limit protection, whether the steel wire rope is fixed by the pressure plate on the drum device and the wedge fixing structure is safe and reasonable.