Knots, Hitches, and Splices 



1413 



in Fig. 43 is not so well filled as is the circle in Fig. 44. From this may be 

 inferred what is really the fact: that four-strand rope differs from three- 

 strand rope in that the former is stronger and more pliable, has a more 

 even surface, weighs more per foot, and, 

 being constructed on a core, the strands 

 are kept away from the very center and 

 therefore chafe one another less as the 

 rope is bent around a pulley. The four- 

 strand rope costs more per pound and 

 there are fewer feet to the pound; never- 

 theless, it is a good investment if 

 properly cared for. If absolutely necessary, a size slightly smaller than 

 would be required in three-strand rope may be used, because of the 

 greater strength and durability of the four-strand rope. 



Rope data. — In the following table the figures given refer to average- 

 grade manila rope, new and without knots. As explained later, knots 

 weaken a rope. The " safe load " given in column V is the greatest load 

 that a single rope should be made to carry, and it is about one seventh 

 of the " breaking load," or one seventh of the pull in pounds required to 

 break a rope of any given size. 



Fig. 43. — Three- 

 strand rope 



Fig. 44. — Four- 

 sirand rope 



TABLE I. Useful Facts about Three-Strand Manila Rope. 



* From the rules by C. W. Hunt and Spencer Miller 



