14 



Indirect 

 Splices 



Fillers 



Arrangement 

 of Splice 

 Materials 



Tie Plates 

 and 



Diaphragms 



Latticing 



121. Where splice plates are not in direct contact with the parts which they connect, 

 the number of rivets therein, which would otherwise be required for a contact splice, 

 shall be increased by 10 per cent, for each intervening plate. 



122. Rivets carrying stress and passing through fillers shall be increased in number 

 1 per cent, for each 1/16 inch of thickness of fillers, and the additional rivets when prac- 

 ticable shall be outside of the connection. 



123. The splice materials shall be so arranged that the strength of each component 

 part of the member spliced, including legs of angles, flanges and webs of beams and 

 channels, etc., will be fully developed. 



124. The open sides of compression members shall be provided with tie plates as 

 near the ends as practicable, and if located farther from the entersection point than 12 

 times the width of either of the flanges to be connected, diaphragms shall be added. 

 Tie plates shall also be provided at intermediate points where the latticing is interrupted. 



125. In main members, the end tie plates shall have a length of not less than \ l / 2 

 times, and intermediate tie plates a length of not less than the perpendicular distance 

 between the lines of rivets connecting them to the flanges; their thickness shall be not 

 less than 1/50 of the distance between connecting lines of rivets. 



126. When intermediate tie plates are used with tension members instead of lattic- 

 ing, they shall be spaced not farther apart in the clear than 15 times the width of the 

 flange to which they are attached, and they shall be connected to the member by not 

 fewer than 3 rivets on each side. 



127. Compression members shall be designed to resist a transverse shear equal to 3 

 per cent, of the axial stress in the member, by latticing, tie plates, or other means. This 

 shear shall be considered as divided equally among all stiffening parts in parallel planes. 



Minimum 

 Size of 

 Lattice Bars 



128. The minimum width of lattice bars shall be: 



3 inches for 1 inch rivets 



Inclination 

 and Spacing 

 of Lattice Bars 



Expansion 



Pier 

 Members 



Rollers 



The minimum thickness shall be 1/40 of the distance between end rivets in the case of 

 single latticing; and 1/60 of this distance for double latticing, riveted at the intersections. 

 Shapes of equivalent strength may be used instead of flats. 



129. Lattice bars shall generally be inclined at an angle of about 60 degrees to the 

 axis of the member when single latticing is used ; and they shall be inclined at an angle 

 of not less than 45 degrees with double latticing; furthermore, the maximum spacing 

 of lattice bars shall be such that the ratio l/r for the portion of single flange between 

 consecutive connections will be smaller than this ratio for the member as a whole. 



130. Provision for expansion, to the extent of 1 inch for each 100 feet, shall be 

 made for all bridges. Spans of less than 80 feet may be arranged to slide upon steel 

 plates with smooth surfaces; but spans of 80 feet and over shall be provided with turned 

 rollers or rockers, or with special sliding bearings, as described below. 



130A. All pier members shall be made in accordance with the Railway Company's 

 Standard Drawings. 



131. Expansion rollers shall be not less than 5 inches in diameter; they shall be 

 connected together by substantial side bars; and shall be effectually guided so as to 

 prevent lateral movement, skewing or creeping. The rollers and bearing plates shall be 

 protected from dirt and water, as far as possible, by suitable curtain plates; and the 

 whole construction shall be such that water will not be retained therein, and that it may 

 be easily inspected and cleaned. 



132. Neither rollers nor rockers shall be used for expansion bearings at the top of 

 trestle posts. 



