346 



STEEL HEAD FRAMES AND COAL TIPPLES 



CHAP. X. 



The bending stresses in crucible steel flat ropes are given in Fig. 8. 



Cages and Skips. For details of cages and skips, see the author's "The Design of Mine 

 Structures." 



Hal Steel Hoisting Ropes, Four 

 strands oF seven wires each. 

 Total unit stress equals direct 

 stressplus bending stress or 

 equals 50,000 Ibs per sq.in. 

 Working unit stress equals 50,000 

 minus bendinq stress. 

 Bending stress in rope equals 

 ~ 14, 200,00 O'd 



K 



d^diam. of each wire in inches 

 -.05575 fors S. 0615 for f rope. 



CJ L * 



R- Radius of hub in inches. 



7 



W/'/. 



36,000 

 U,000 



28,000 

 26,000 

 24,000 

 Z?,000 



J?,000 

 10,000 

 8,000 

 6,000 

 4,000 

 2,000 



50 36 42 43 54 60 66 7Z 

 Diameter of fee/ Hubs jn Inches 



FIG. 8. SAFE WORKING STRESSES, L, IN CRUCIBLE STEEL, FLAT HOISTING ROPE. 



Sheaves and Safety Hooks. For details and data on sheaves, safety hooks, etc., see the 

 author's "The Design of Mine Structures." 



EXAMPLES OF STEEL HEAD FRAMES. The detail plans for three steel head frames 

 taken from the author's "The Design of Mine Structures" are excellent examples of steel head 

 frames. Data on 16 steel head frames are given in Table V. 



