1)      Each one circle layer of the Grooved drum has two parallel groove and two groove section

2)      Make the cable even smooth ;load even distribution  

3)      Prevent  cross &mess  in cable rolling working happening

If the winch is worn out, you no need to chage another new.Especially in the marine.You only make a lebus sleeve to install or melt in the winch.that method can solve the rope intertwist problem and save money and time for the working.