— 71 一 
For the flanges of rolled beams the intensity is to be taken 
equal to five (5) tons, and for those of built beams four (4) tons on 
the gross section. 
Tlio intensity of working bending stress for pins and rivets 
belonging wholly to tlio lateral systems or sway bracing is to be 
taken equal to eleven and a quarter (11+) tons, and for all otlier 
pins and rivets seven and a half (7J) tons. 
Where steel pins of good quality are employed, the intensity 
may be assumed at twelve (12) tons for trusses and eighteen (18) 
tons for lateral systems. 
Tlio intensity of ■worldng bearing stress for pins and rivets 
belonging wholly to the lateral systems or sway bracing is to be 
nine (9) tons, and for all other pins and rivets six (6) tons. 
Hip verticiUs in pony trusses, having lass tlian five (5) iDauels, 
ai’c to bo stiiYonecl so as to resist compression duo to initial tension 
°n counters. If the section employed consist of two cliaunels, tlie 
het section of the webs alone is to bo relied upon to resist tension ， 
aU( l ü* trussed bars be employed the intensity of working tensile 
stress on tlio net section is to be reduced to tliroo (3) tons. 
Middle panel diagonals, counters, lateral rods, vibration rods 
如 d all other adjuBtablo roils are to liave their ends enlarged for the 
SCI， ® W threads according to tlio dimensions given in Chapter XIX, 
and aro to be provide tl with check nuts. 
All threadö except tlioso on the ends of pins must bo of a 
^mfonn standard. 
Trussing is to be employed only for stiffened bottom chords 
乳 nd hip verticals. The least allowable section for trussing bars is 
a q uar ter ( 全 ） of an inch by three (8) inches. 
The least dimensions for the upper plates in top chords and 
batter braces aro to be taken from tlio following table. 
. With eliannols greater than seven (7) inches in depth, should 
lie width of plate eraployed exceed that given iu tlio table by from 
Jorty (40) to sixty (60) per cent., tlie thickness must bo increased 
ド ope sixteenth ( 7 ^) of an inch: if it exceod by from sixty (GO) 
? ei ghty (80) per cent., tlio thickness must be increased by one 
哪她 ⑷ of a ム uch. 
Depth of Chord. 
Least Tnickness. 
Least Width, 
6 f, 
V 
8" 
r 
r 
9" 
8 7/ 
9" 
i" 
10" 
11 ^ 
IO" 
12" 
各" 
r 
1 2 辜 " 
15 " : 
】 5 " 
r 
jSV 
1 8 " 
r 
2 ず 
20" 
22° 
27" ] 
24" 
r 
W ； 
Intensities of Work- 
ing Beinling Stress. 
Intensities of Work- 
ing Bearing Stro 33 • 
Hip Verticals in rony 
Trusses. 
Up?et Roils. 
Tlircfttls. 
Trussing. 
Least Dimensions for 
Chord aiul Batter 
Brace Plates. 
