NOTES ON CHAIN CABLES. 161 



It will be observed that in this case there are two sections at which the bend- 

 ing moment is zero. The tensile stress reaches a maximum for the outer fiber at 

 D, and for the inner fiber at about the point E. The compression is greatest at point 

 C, but is only a little over one-half that at C in the case of the open link. The ten- 

 sile stresses are also somewhat smaller than for the open link. 



EFFECT OF STUD. 



The effect of the stud upon the distribution of stress is to reduce the maximum 

 tensile stress about 20 per cent and the heavy compressive stress at C about 50 per 

 cent. The conclusion is then that if the stresses are kept within the elastic limit, the 

 stud increases the strength. 



The experiments of Committee D of the United States Board, Commander 

 L. A. Beardslee, Chairman, appointed to test iron, steel and other metals (Execu- 

 tive Document No. 98 — House of Representatives, 45th Congress, Second Session) 

 indicate that when the link is stressed beyond the elastic limit the effect of the stud 

 is to weaken the link. 



This may be explained theoretically by the fact that as the link is deformed the 

 width of the open link is decreased, whereas the width of the stud link remains the 

 same. The effect of the reduction in width of the link is to reduce the bending mo- 

 ment and stresses within the link. 



I am of the opinion that this rule cannot be applied without reservation to all 

 lengths and forms of links and to all kinds of iron. In the case of the 3-inch close link 

 chain manufactured for the Panama Canal lock gates, they tested to about 485,000 

 lbs. breaking stress, whereas the 3-inch stud link chain pulls to at least 525,000 lbs. 

 It would appear that the deformation in the close link chain, due to closing in of the 

 sides, bending the crown and quarters of the link closely about the adjoining link, 

 strains the material more than in the case of the stud link chain. It is entirely pos- 

 sible that the eflfect of this greater deformation on the breaking stress would be 

 different with a soft, ductile iron than with a hard, brittle iron. The manner in 

 which the close link and stud link chain deforms is shown in Figs. 10 and 11, Plate 

 91, respectively. 



We are concerned, however, more particularly with the strength of the chain 

 within the elastic limit, and within this limit there appears no question of the su- 

 periority of stud link chain. The latter has the further advantages, that it does not 

 foul so readily and oflfers greater structural strength for the resistance of cross- 

 stresses and blows tending to deform or rupture it by forces other than those of pure 

 tension. 



END WELD VERSUS SIDE WELD. 



An examination of the table and diagram (Fig. 9, Plate 90) of stresses in 

 stud links indicates that theoretically the section at the end of the minor axis is 

 subject to less severe stresses than is the section at the end of the major axis. 



With a weld on the side the stresses over the weld are resisted solely by the 



