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turned so as to press the floor beam against the bottom of tlie post (or the filling 
piece at the first panel point) and are prevented from getting loose by lock nuts. 
■Hds attachment is illustrated on PI. II, Fig. 10. Floor beams in deck bridges should 
resfc upon tlio top chords, directly over tlie posts : their lower flange 日 should bö 
rivetted to the chord, plate, and brackets of angle or channel iron should be used to 
prevent injury from the rackiug effect of passing trains. This detixil is sliown 011 
P 】 . IX, Fig. 15. It is not legitimate to use such floor beams as upper lateral struts, 
although they undoubteclly aid the upper lateral system. 
The two floor systems referred to n ； few lines back avo for these two cases viz., 
where there arc wooden sliims resting oil the track stringers and where there arc 
not. The former is employed wlicn the stress in the eud lateral rod is not sufficient 
to necessitate the use of double rods, and tlie latter in all other cases, tlie reason 
being that four rods passing througli a sliim ■would cut it up too much, besides 
taking it inconvenient to get the rods and sliims into place. 
Iu tlie first case the track stringers rest on shelves of angle iron supported by 
short stifiening angles^ tincl aro also attached by bent plates rivetted to tlie webs of 
both beams and stringers. To obtain greater stiffness, plates of tlie full width of the 
top flanges may bo run through the lateral struts and rivetted to the flanges of 
adjacent stringers, but these are not absolutely necessary and may be omitted, ü so 
desired. This style of floor system is shown on PI. III. 
. Iu the second case tho stringers pass over ilio floor beams, wliicli are a few 
mclies lower than in tlie other case, and are made continuous from end to end. of 
span by means of splice plates on both wobs aucl flanges. Heavy stiffeners are 
placed beneath tlie points of support of the stringers to avoid all tendency to buckle 
tlie wob of tlie beam. Additional support and rigidity are given to the connection by 
rackets extending from the bottom of tlie bo am to the bottom of the stringers. 
This metho(Us illustrated on PI. IY. 
All built track stringers Lave stiffening frames lying in planes transverse to tlieir 
length jiikI spaced from seven to ten feet apart. None fire required cit tlie ends, 
^vlieu the stringers abut against the floor beams, but tliere is one near each end 
when tlao stringers rest thereon. Extra stiff frames aro required at the ends of 
stringers which rest upon tlie piers or abutments. Bed plates witli grooves or some 
similar arrangomont aro to be used for tho stringers where they bear upon masonry, 
a üd are anchored to same in a manner similar to that described for the case oi 
pedestal bed plates. Similar bed plates aro used at ono end of plato girder spans. 
Lock nuts are used on all adjustable members : auy style tliat will act efficiently may 
be employed, but those illustrated ou PI. II Figs. 5, 6 and 10 are quite simple and 
effective. 
• Ornamental work can be placed at the brackets on tlie portals, at the intersec- 
tion of the portal vibration rods, above the upper portal struts, and even on inter- 
mediate brackets. A small amount of ornmental work will go a long way in 
an iron bridge. 
In floor beams, track stringers and plate girders it is hotter to concentrate as 
much of the sectional area of tlie flanges iuto the angles aud to use plates sparingly» 
