Which lay type is associated with untwisting tendency and is not recommended for single-part hoisting?

Which lay type is associated with untwisting tendency and is not recommended for single-part hoisting?

• A. Regular lay
• B. Right lay
• C. Stiff lay
• D. Lang lay

Answer: (D)

Lang lay describes a rope where the strands are laid with a longer pitch around the core. That longer pitch makes the rope more prone to untwisting when it’s under tension. In a single-part hoist, the rope goes directly from the drum to the load with no other rope parts to balance that twist, so the untwisting tendency shows up as twisting of the rope on the drum and through the sheaves. This can lead to uneven wear, slipping, or unstable load control, which is why lang lay is not recommended for single-part hoisting. Other lays—regular, right, or stiff lay—have less tendency to unwind in typical loading conditions, so they’re generally more suitable for single-part operations depending on the specific application.

Lang lay describes a rope where the strands are laid with a longer pitch around the core. That longer pitch makes the rope more prone to untwisting when it’s under tension. In a single-part hoist, the rope goes directly from the drum to the load with no other rope parts to balance that twist, so the untwisting tendency shows up as twisting of the rope on the drum and through the sheaves. This can lead to uneven wear, slipping, or unstable load control, which is why lang lay is not recommended for single-part hoisting. Other lays—regular, right, or stiff lay—have less tendency to unwind in typical loading conditions, so they’re generally more suitable for single-part operations depending on the specific application.