The drum can be classified into three types ：
1. plain drum /smooth drum/slotless drum
2. LBS grooved drum
3. Spiral drum/helical drum
Compared to the other two drums，LBS grooved drums have a lot of advantages as following：
1.With LBS grooving，it is possible to calculate exactly the direction of the forces that the rope imposes on the drum beacuse the spooling is totally controlled and so the rope‘s behaviour is entirely predictable.
2. To keep the spooling under tension and make it spooling orderly
3. To incrase the service life of wire rope .