In which situation is the D/d efficiency more significant when securing wire rope lashing?

The significance of D/d efficiency in securing wire rope lashing is particularly pronounced when the reduction exceeds 20%. This is because D/d efficiency refers to the ratio of the diameter of the pulley (D) to the diameter of the rope (d). A reduction greater than 20% indicates that the rope is subjected to an excessive curve, leading to a greater potential for inefficiencies or a reduction in the overall strength and effectiveness of the lashing.

When the D/d ratio falls below optimal levels, the bending and flexing of the rope can cause increased wear, potential damage, and a decrease in its capacity to hold loads securely. This is crucial in lashing applications where safety and performance are paramount.

In contrast, while lower quality rope, high weight loads, or synthetic lashings can play a role in the overall application of lashing, they do not specifically highlight the critical thresholds of the D/d efficiency like the reduction exceeding 20% does. Understanding the implications of the D/d ratio helps to ensure that the lashing method chosen is safe and effective for the intended load and use conditions.