Does Twisting Effect Rope Strength?

Twist reduces the strength of a braided rope and can lead to unexpected failures. In order to avoid this, it is important to be able to identify twist in a rope, take appropriate actions to remove it from the line, and prevent further twisting.

Why does Twist Reduce the Strength of a Braided Rope?

As a braided rope, that has been twisted, is loaded, the strands become loaded unequally. Depending on the direction of twist either the S- or Z-strands will take more of the load. Figure 1 illustrates this phenomenon, where all of the Z-strands are tight and all of the S-strands are loose. The loose S-strands will not bear the same load as the tight Z-strands. The tight strands will carry more load than the loose strands leading to a loss in rope efficiency.
Fig. 1
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