16 



81. Where the floor timbers are supported at their ends 

 on the flange of one angle, such angle must have two rows 

 of rivets in its vertical leg, spaced not over 3 inches apart. 



82. For main members and their connections no material 

 shall be used of a less thickness than f of an inch ; and for 

 laterals and their connections, no material less than ^ of 

 an inch in thickness; except for lining or filling vacant 

 spaces. 



AMtead 83. Connection angles for stringers or floor beams shall 

 "* have no leg less than 3^ inches or be of less thickness than 

 $ inch. ( 102.) 



No angle less than 3 x 2^ inches shall be used for bracing. 



The width of channels used for bracing shall not be less 



than 6 inches lor single or 8 inches for double track bridges. 



Eye-Bars. 84. The heads of eye-bars shall be so proportioned and 



made that the bars will preferably break in the body of 



the original bar rather than at any part of the head or neck. 



The form of the head and the mode of manufacture shall be 



subject to the approval of the Engineer of the Railroad 



Company. (Art. 141.) 



85. The bars must be free from flaws and of full thick- 

 ness in the necks. They shall be perfectly straight before 

 boring. The holes shall be in the centre of the head, and 

 on the centre line of the bar. 



86. The bars must be bored to lengths not varying from 

 the calculated lengths more than -^ of an inch for each 25 

 feet of total length. 



87. Bars which are to be placed side by side in the struc- 

 ture shall be bored at the same temperature and of such 

 equal length that upon being piled on each other the pins 

 shall pass through the holes at both ends without driving. 



88. The lower chord shall be packed as narrow as possi- 

 ble. 



89. The pins shall be turned straight and smooth ; chord 

 pins shall fit the pin-holes within -^ of an inch, for pins less 

 than 4^ inches diameter ; for pins of a larger diameter the 

 clearance may be -fa inch. 



90. The diameter of the pin shall not be less than eight- 



