. Details of railroad truss-bridges . GERS.,In decK bridges several different methods are used for con-necting the floorbeams to the intermediate posts or upper chords,sometimes they are attached to the intermediate posts so low thatwhen the stringers are laid directly upon them,their upper flangesare on a level with the upper flanges of the top chord. When thisis done the cross-ties are usually long enough so that the upperchord can aid the stringers in supporting them. The floorbeams ofthe Northern Pacific Railroads standard decK bridges extend abovethe upper chord a distance equal to one-ha
. Details of railroad truss-bridges . GERS.,In decK bridges several different methods are used for con-necting the floorbeams to the intermediate posts or upper chords,sometimes they are attached to the intermediate posts so low thatwhen the stringers are laid directly upon them,their upper flangesare on a level with the upper flanges of the top chord. When thisis done the cross-ties are usually long enough so that the upperchord can aid the stringers in supporting them. The floorbeams ofthe Northern Pacific Railroads standard decK bridges extend abovethe upper chord a distance equal to one-half of their height. Inthis case the stringers are fastened to the floorbeams in a mannersimilar to the method used in through bridges. HIP-VERTICALS, Below the floorbeam connection,the hip-verticals are some-times composed of comparatively light loop-bars. These loop-barssupport only the weight of one panel length of the bottom most cases however,the hip-verticals are of uniform cross-sec-tion throughout their entire 32. CONNECTION OF TOP CHORDS. shows a method used by the Illinois Central Rail-road for making continuous the top chords of two adjacent this case the vertical posts are attached to the bottoms of theend posts by means of bent plates. The floorbeams rest directlyupon the tops of the vertical posts and the stringers and top chordsare fastened to the webs of these beams. The function of the chordmembers in this particular case is to help hold in place the verti-cal post and the floorbeam. The vertical posts at the end of each bridge are rigidlyfastened together with heavy lateral bracing. This is essential;since any lateral movement of the post would prove disastrous tothe connections. The distance between the vertical posts of two ad-Joining spans is usually three to four feet. A short chord Is usedto span this distance,and is fastened to the posts,as shown in When only one decK bridge is used to span a waterway,theabutmen
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttheses, bookyear1910
