Wire rope damage due to bending fatigue and drum crushing

The steel wire rope of a properly designed and maintained crane should have a reasonably long service life and one day be discarded because of fatigue, the wire rope equivalent of old age. But often wire ropes don't get very old: they might die prematurely because of excessive abrasion or corrosion (the wire rope equivalents of skin cancer). Here, proper wire rope relubrication might be the answer. Wire ropes might also die prematurely because of mechanical or structural damages (the wire rope equivalents of being run over by a bus). Improved crane design and proper wire rope and crane usage will help to avoid these problems. But what about drum crushing? lf a wire rope dies because of damages received when spooling on and off a drum, is that part of normal rope life? Many crane designers and users think so. But they are wrong: When drum crushing occurs, the wire rope damages itself. Drum crushing is the wire rope equivalent of suicide. This paper explains the mechanisms and shows how drum crushing can be avoided.

 Author(s): Verreet, R.