. A manual of the principles and practice of road-making : comprising the location, consruction, and improvement of roads (common, macadam, paved, plank, etc.) and railroads . rcum-stance that most American roads with longitudinal timbershave been laid with plate rails, so thin that their endssometimes spring up so as to form snake-heads, andhave thus received the scarcely caricatured description of A hoop tacked to a lath. Such roads have the defectsof instability, insecurity, inequality of surface, waste ofpower, resistance to speed, and great expense of main-tenance. But these faults do not
. A manual of the principles and practice of road-making : comprising the location, consruction, and improvement of roads (common, macadam, paved, plank, etc.) and railroads . rcum-stance that most American roads with longitudinal timbershave been laid with plate rails, so thin that their endssometimes spring up so as to form snake-heads, andhave thus received the scarcely caricatured description of A hoop tacked to a lath. Such roads have the defectsof instability, insecurity, inequality of surface, waste ofpower, resistance to speed, and great expense of main-tenance. But these faults do not belong to the system it-self, but to its imperfect execution. The rails should beheavy edge rails, of suitable form, and in contact with thetimbers for their whole length ; and the longitudinal timbers 306 RAIL-ROABS. should be tied together by cross-sleepers. The best railroad in the world, the Great Western, has such continuous bearings. The wood may be preserved fromdecay by any of the methods noticed on page 135. n n a n n u n o u TJ 3 In the above figure, A is the ground plan, B the sideview, and C the end view, of such a system of railroad. Fig. 136. ~). For these longitudinalbearings, chairs are un-necessary, and peculiarlyshaped rails are favorite form is thatshown in Fig. 136, whichhas been made to weighfrom 35 to 60 lbs. per is fastened by screws, 4 inches long, the heads of whichare countersunk on the inner side, so as to be out of theway of the flange of the wheel. At the joints, four screwsare employed. Sometimes the rails are fastened by spikes with bentheads, driven just outside of them, and clasping themirmly. The greater difficulty of packing the gravel around CONTINUOUS SUPPORT. 307
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Keywords: ., bookcentury1800, bookdecade1850, booksubjectrailroa, bookyear1853
