Page 49 - The Pocket Guide to Outdoor Knots

a half, and the practice arose of calling it 45% efficient, so the breaking strength
of a rope with an overhand knot tied in it is only 45% of that claimed by the

manufacturer for the new unknotted line. The reef knot (page 40) is almost as
weak.

Knots with gentler curves and less severe nips proved less destructive. The
clove hitch (pages 86–87) and the round turn & two half-hitches (page 45) are at

least 70% efficient, that is, they reduce the breaking strength of any rope in
which they are tied by no more than 30%—but still a considerable percentage.

Clearly, when ropes were likely to be operating close to their breaking strengths,
the choice of the strongest knots was a serious consideration and a matter for

shrewd and experienced judgment.