152 



TOWERS AND TANA'S FOR WATER-WORKS. 



6.5 X 0.375 X 55,000= 134,062 Ibs. = strength of solid 

 plate. 



(6.5 0.8 125) X 0.375 X 55,000= 1 1 7, 304 Ibs. = strength 

 of net section of plate at AB. 



0.5185 X 4 X 70,300 = 145,802 Ibs. = strength of 4 rivets 

 in double-shear. 



0.5185 X 38,000= 19,703 Ibs. = strength of I rivet in 

 single-shear. 



This last result must be added to the strength of four 

 rivets in double shear thus, 145,802 -|- 19,703 = 165,505 = 

 shearing-strength of all the rivets. The net section of plate 



FIG. 44. DOUBLE-WELT BUTT-JOINT. 



is weakest; therefore, 117,304-7-134,062 = 87.5 percent, 

 efficiency of joint. 



It will no doubt be observed that the strength of rivets in 

 this joint is largely in excess of the strength of net section of 

 plate, and the question will arise, Why increase the width of 

 the inner covering-strip and add two more rivets? As stated 

 above, this was done to increase the net section of plate at AB> 



