15 



73- All other angles, filling and splice plates on the webs 

 of girders and riveted members must fit at theirs ends to 

 the flange angles, sufficiently close to be sealed, when 

 painted, against admission of water. 



74. Web-plates of all girders must be arranged so as not 

 to project beyond the faces of the flange angles, nor on the 

 top be more than T ^ inch below the face of these angles, at 

 any point. (75, 158.) 



75. Wherever there is a tendency for water to collect, 

 the spaces must be filled with a suitable waterproof material 



76. In girders with flange plates, at least one-half of the Fian ge piai*s 

 flange section shall be angles or else the largest sized angles 



must be used. Flange plates must extend beyond their 

 theoretical length, two rows of rivets at each end. 



77. The flange plates of all girders must be limited in 

 width so as not to extend beyond the outer lines of rivets 

 connecting them with the angles, more than five inches or 

 more than eight times the thickness ol the first plate. Where 

 two or more plates are used on the flanges, they shall either 

 be of equal thickness or shall decrease in thickness outward 

 from the angles. 



78. In lattice girders and trusses the web members must Lattice Girders, 

 be double and connect symmetrically to the webs of the 



chords. The use of plates or flats, alone, for tension mem- 

 bers must be avoided, where it is possible; in lattice 

 trusses, the counters, suspenders and two panels of the 

 lower chord, at each end, must be latticed ; all other ten- 

 sion members must be connected by batten plates or latticed. 



( 970 



79. The compression flanges of beams and girders shall be compwwioo 

 stayed against transverse crippling when their length is 



more than sixteen times their width. 



80. The unsupported width (distance between rivets) of 

 plates subject to compression shall not exceed thirty times 



thickness; except cover plates of top chords and end 

 posts, which will preferably be limited to forty times their 

 thickness ; where a greater relative width is used in chords 

 and end posts, however, only forty times the thickness 

 shall be considered as effective section. 



