What is the term for the maximum angle the wire rope should travel between the sheave and the drum to maintain optimum efficiency?

• A. Sag angle
• B. Fleet Angle
• C. Rope angle
• D. Drum angle

Answer: (B)

Fleet angle is the angle the rope travels between the drum and the sheave. Keeping this angle small reduces side loading on the rope and uneven wrap, which lowers friction losses and wear, helping maintain optimum efficiency and rope life. If the angle becomes too large, the rope loads more on one edge, increasing wear and energy loss. That’s why the term fleet angle is used for this rope-path condition. Other terms like sag angle, rope angle, or drum angle don’t specifically describe this relationship between the drum and the sheave.