400 STRUCTURAL DRAFTING. CHAP. XII. 



is the same. Bill first the main material in the member, and follow with the smaller pieces, begin- 

 ning at the left end of a girder, or at the bottom of a post or girder. On a column each different 

 bracket shall be billed complete by itself. Do not bill first all the angles and then all the flats; 

 for example when the end stiffeners in a girder are billed, the fillers belonging to them shall follow 

 immediately after the angles, and so on. 



When machine-finished surfaces are required, the drawing and the shop bill shall specify the 

 finished width and length of the piece, the proper allowance for shearing and planing being made 

 in the mill bill. When the metal is to be planed as to thickness, the drawing and the shop bill 

 shall specify both the ordered and the finished thickness; one pi. 15 in. X f in. X I ft. 6 in. (planed 

 from 13/16 in.). 



Field Rivets. A " Bill of Field Rivets" shall be made for each structure. The " Bill of Field 

 Rivets" shall give in order the number, diameter, grip, length and the location of the rivets in 

 the structure. The number of field rivets to be furnished to the erector shall be the actual number 

 of each diameter and length required, plus 15 per cent, plus 10. 



Field bolts shall be billed on " bill of rivets and bolts" only. Bill them similarly to field rivets, 

 and give the drawing number on which they are shown; 4 bolts | in. X 2 in. grip, 3 in. U. H. 

 stringers "S" to floorbeam "F" drawing No. 13, 4 hex. (or 4 square) nuts for above bolts. Bill 

 of bolts and bill of field rivets shall be prepared and placed in the shop in time to be made with 

 other material. 



General Notes. Full information regarding the following points shall appear on the drawings, 



where practicable as "General Notes." Loading , Specifications , Material 



, Rivets , Open Holes , Reaming Requirements , Other Special 



Requirements , Painting. 



Erection Plan. Make erection plans simultaneously with the shop plans, and keep same up 

 to date. The erection plans must show plainly the style of connections; joints in pin spans are to 

 be shown separately to a larger scale. For the erection plan of a truss bridge see Fig. 7. Shipping 

 bills showing the number of pieces, erection mark, and weight shall be made for each shipment. 



Subdivisions. Every contract embracing different classes of work shall have a subdivision 

 for each class. These subdivisions will be furnished by the chief draftsman. Drawings, shop 

 and shipping bills must be kept separate for each class. 



PLATE GIRDER BRIDGES. General Rules. The plate girder span shall be laid out 

 with regard to the location of web splices, stiffeners, cover plates, and in a through span, floor- 

 beams and stringers, so that the material can be ordered at once. Locate splices and stiffeners 

 with a view of keeping the rivet spacing as regular as possible; put small fractions at the end of 

 girder. Stiffeners, to which cross-frames or floorbeams connect, must not be crimped, but shall 

 always have fillers. The outstanding leg shall not be less than 4 in., gaged 2f in.; this will enable 

 cross-frames or floorbeams to be swung into place without spreading the girders. The second pair 

 of stiffeners at the end of girder over the bed-plate shall be placed so that the plate will project 

 not less than I in. beyond the stiffeners. 



Always endeavor to use as few sizes as possible for stiffeners, connection plates, etc., and 

 avoid all unnecessary cutting of plates and angles. For this purpose locate end holes for laterals 

 and diagonals so that the members can be sheared in a single operation. In spans on a grade, 

 unless otherwise specified, put the necessary bevel in the bed-plate and not in the base-plate. 

 In short spans, say up to 50 ft. put slotted holes for anchor-bolts in both ends of girders, f in. 

 larger diameter than the anchor bolts. 



In square spans, show only one-half, but give all main dimensions for the whole span. In 

 skew spans show the whole span; when the panels in one-half of span are same as in the other 

 half, give the lengths of these panels, but do not repeat rivet-spacing, except where it differs. 



In the small scale diagram, which shall appear on every sheet, unless span is drawn in full, 

 show the position of stiffeners, particularly those to which cross-frames or floorbeams connect. 



Deck Plate Girder Spans. On top of sheet show a top view of span, with cross-frames, 

 laterals and their connections complete, with the girders placed at right distances apart. Below 



