Special 

 Sliding 

 Bearings 



Shoes and 

 Bed Plates 



Inclined 

 Bearings 



Lead 



Anchor Bolts 



Camber 



Name 

 Plates 



Number 

 Boards 



15 



133. Sliding plates for the expansion bearings of spans of 80 feet and over shall be 

 of hard bronze, or of some other hard non-corrosive material; they shall be chamfered 

 at the ends, and shall be held securely in position ; furthermore, they shall be arranged 

 so that the sliding surfaces thereof cannot become clogged by dirt. 



134. Shoes and beds shall be designed for rigidity and stability and to distribute the 

 total reaction uniformly without exceeding the Unit Stress; they shall be of cast or 

 rolled steel. Spans 30 feet and longer shall have hinged or disc bearings at each end 

 unless otherwise specified. 



135. For spans on an inclined grade and without hinged or disc bearings, the bed 

 or masonry plates shall be beveled so that the masonry surfaces will be level . 



135A. One sheet of lead, 1/4 inch in thickness shall be supplied to go between each 

 pier member and the masonry bridge seat. Lead sheets shall be 1 inch larger each way 

 than the pier member castings or bed plates under which they are designed to be placed. 



136. Anchor bolts shall not be less than \ 1 /^ inches in diameter; and when subject 

 to tension they shall be long enough to engage a mass -of masonry weighing not less than 

 \J/2 times the amount of the uplift. 



137. Unless otherwise specified, trusses shall be cambered for the dead load plus 

 one-half the live load without Impact. 



137A. There shall be one name plate provided for and fastened to each span of 

 any bridge. Name plates shall be made in accordance with the Railway Company's 

 Standard Drawings to show the name of the Railway Company, the date of manu- 

 facture, and the Contractor's Name and Address. 



137B. One or more number boards shall be provided for each bridge. These shall 

 be in accordance with the Railway Company's Standard Drawings. In the case of 

 through bridges, where numbers can be painted on the end posts of spans, no special 

 number boards will be required. 



General 



Straightening 



Finish 



Rivet Holes 



Punched 

 Holes 



WORKMANSHIP 



138. All parts forming a structure shall be built in accordance with drawings approv- 

 ed by the Engineer. The workmanship and finish shall conform to the best practice in 

 modern bridge works. Materials shall have clean surfaces before being worked in 

 the shop. 



139. Rolled material, before being laid off or worked, must be straight. If straight- 

 ening or flattening is necessary, it shall be done by methods that will not injure the 

 material. Sharp kinks or bends will be cause for rejection. 



140. Finished members shall be true to line and free from twists, bends, and open 

 joints. 



141. Shearing and chipping shall be neatly and accurately done, and all portions 

 of the work exposed to view shall be neatly finished. When specified by the Engineer, 

 sheared edges of all material over 5/8 inch thick in main members, including splice and 

 connection plates, shall be planed at least 1/8 inch. Re-entrant cuts shall be filleted 

 before being cut. 



142. Rivet holes in main members shall either be drilled from the solid, or sub- 

 punched and reamed. In lateral and sway bracing, and in secondary parts such as tie 

 plates, lattice bars, etc., rivet holes may be punched full size. 



143. Where reaming is not required, the diameter of the punch shall not be more 

 than 1/16 inch greater than the nominal diameter of the rivet; nor the diameter of the 

 die more than 1/8 inch greater than that of the punch. Punching shall be accurately 

 done. Drifting to enlarge unfair holes will not be allowed ; but if holes must be enlarged 

 to admit the rivets, they shall be reamed. Poor matching of holes will be cause for 

 rejection. 



