RELATIVE BENDING STRENGTH OF CROSSARMS 45 



As previously shown, IITcbb — 4.1751 

 2Tc s2 = 4.1738 



llTc = 0.0013 

 ITc - 0.0007 

 D - r = 0.09375" 

 s = 3.7680" 



3.8618" 

 d = 3.7625" 



g for Tc - 0.0993" 



The results of this computation apply also to the minimum Sys" x 4" pin- 

 hole section at the ends of the arm. The depth (d) of the rectangular por- 

 tion of the end pinhole sections will be the same as at the extreme ends of the 

 arm, viz. 3.6688". 



Computation IV. Moment of Inertia of Top Segment of Nominal (Jj" x 4ys'') 

 Pinhole Section: 



Since this computation was made in the same manner as Computation 

 III, only the results are here shown: 



d = 3.8593" 

 g = 0.1019" 

 Tc — 0.1630 sq. ins. 

 ITc = 0.0008 



