. The railroad and engineering journal . ment transversely to the rail. The lower sides of the tie, which are horizontal for adistance of 85 centimeters f34>^ in.) from the ends, arearched downwards toward the middle, in such a way as toinduce the lateral faces of support to imbed themselves inthe ballast and thus to oppose the tendency to movementin the direction of the length of the rail. In the upper surface or plan of the tie, the top or tablewidens at the ends and is drawn in at the center. Thewidening at the end furnishes a greater supporting surface,and, consequently, contributes in
. The railroad and engineering journal . ment transversely to the rail. The lower sides of the tie, which are horizontal for adistance of 85 centimeters f34>^ in.) from the ends, arearched downwards toward the middle, in such a way as toinduce the lateral faces of support to imbed themselves inthe ballast and thus to oppose the tendency to movementin the direction of the length of the rail. In the upper surface or plan of the tie, the top or tablewidens at the ends and is drawn in at the center. Thewidening at the end furnishes a greater supporting surface,and, consequently, contributes in some measure to thestabiHty of the rail. As to this narrowing in the middle of the tie, M. Post,the Engineer of the company, sees in it a special advan-tage for roads with poor ballast, and where the tampingis little cared for. In roads which are placed under suchunfavorable conditions, the tie, if of uniform size, forcesitself down into the ballast and often finds a point of restin the center, causing an oscillation or rocking movement. of the track. The reduction of size in the center of the tie,while diminishing the reaction of the ballast at that point,will result in keeping the principal resistance at the outsidenear the rails. At the same time, the increase of heightat the end of the tie increases considerably its stiffness,and keeps it from bending while being transported to theroad or in a neglected track. The rails, which weigh 40 kilogrammes to the meter(80 lbs. per yard), are secured to the ties by clips orwashers, of a form shown in the cut, and by bolts withIbbotson nut-locks. We will now see under what conditions the experimentswith steel ties are made. A model section of 576 meters (1,890 ft.) long on themodified Post ties of steel, with rails 12 meters long andweighing 40 kilogrammes per meter, is placed betweenanother section of the same length (576 meters) laid withrails kilogrammes to the meter (68 lbs. per yard), and9 meters long, on Post steel ties of
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectrailroa, bookyear1887
