WORKING STRESSES IN ROUND WIRE ROPE. 



65,000 



60,000 



840 



5teel Hoistinq Ropes with six 

 strands oF nine teen wires each. 

 Total unit stress equals direct 

 stress plus bendinq stress or 

 equals 50,000 Ibs.per sq.in. 

 Working unit stress equals 50,000 

 minus bendinq stress. 

 Bendinq stress in rope equa/s: 



3*1,894,000 J- 



Safe Working Load in rope 

 equals : 



d=diam. oF rope in inches . 

 D =diam. oFdrum in inches. 



/ Z 3 4 5 d 78 9 10 II IZ 13 14 15 

 Diameter of Drum In Feet 



FIG. 7. SAFE WORKING STRESSES, L, IN CRUCIBLE STEEL, ROUND HOISTING ROPE. 



depending upon the rope, and varies from 9.27 for haulage rope to 27.81 for tiller rope. For 

 standard hoisting rope, C = 15.45. Substituting E = 29,000,000, 



c = 0.4 d 1 , and d' , we have 



D-d 



Since d is very small as compared with the values of D used in hoisting, formulas (4) and (8) 

 give practically the same results. 



