If a knot or hitch of any kind is tied in a rope its failure under
stress is sure to occur at that place. Each fiber in the straight part
of the rope takes its proper share of the load, but in all knots the
rope is cramped or has a short bend, which throws an overload on those
fibers that are on the outside of the bend and one fiber after another
breaks until the rope is torn apart. The shorter the bend in the
standing rope the weaker the knot. The approximate strength of several
types of knots in percent, of full strength of a rope is given in the
table below, as an average of four tests.
1. Full strength of dry rope 100%
2. Eye splice over an iron thimble 90%
3. Short splice in rope 80%
4. Timber hitch, round turn and half hitch 65%
5. Bowline, slip knot, clove hitch 60%
6. Square knot, weaver’s knot, sheet bend 50%
7. Flemish loop, over--hand knot 45%