. e from originof curve to point of reversion- But if the point of reversion be made at the point of frog, thedistance between nearest rails of tracks being 7 feet, we have 6 : 7:: 800: 933*3= radius of curve with which to leave frog, and6:7 :: 98 : 114o = distance from frog to end of turnout. Or making the movable rail tangent, and its opening oi- inclies, angle of opening being 1 IS, the point of reversion being made at frog, to find the angle of frog, we have: cosine T IS=99974 6-54933-3 = -OOTSO •99274 == cosine 6 55 nearlv the s
. e from originof curve to point of reversion- But if the point of reversion be made at the point of frog, thedistance between nearest rails of tracks being 7 feet, we have 6 : 7:: 800: 933*3= radius of curve with which to leave frog, and6:7 :: 98 : 114o = distance from frog to end of turnout. Or making the movable rail tangent, and its opening oi- inclies, angle of opening being 1 IS, the point of reversion being made at frog, to find the angle of frog, we have: cosine T IS=99974 6-54933-3 = -OOTSO •99274 == cosine 6 55 nearlv the same as before. TURXOUTS OX CURYES. Fig. 19. Suppose the turnout is on a curve running in the same direction,say a 2^ with a radius of 2865 feet. Xow an 800 feet radius givesa 7° 10 curve, and 7 10 — 2 = 5^ 10 = relative departure frommain track But the radius of a 5^ 10 = 1109 feet; then .V2 X 1109 X 6 = ar==115-3 — distance from origin of curve topoint of to make a turnout from a 2~ curve and running thesame way would require 115 Locating Side Tracks, Etc. 401 If it were required to keep the distance the same as on a straightline, it would be necessary to make the 7° 10 curve a 9° 10curve of 625 feet radius. If the 2° curve run in the opposite direction of the turnout, andthe radius was 800 feet, then the convergence will be 7° 10 + 2°= 9° 10 curve, and the radius of a 9° 10 curve being 625 feet, wehave: a: = 1^2 X 625 X 6 = ^ToOO = 866 — distance from originof curve to point of frog. When the main track is a curve^ and it is required to get on to a side track running parallel thereto. Note.—In treating of turnouts, When the main and side track are curves, the movablerail is considered a part of the curve used for turnoai, according to method 1st. Let E M be the main track on a curve of 2865 feet radius. It isproposed with a turnout from E, with a curve of 800 feet radius, tofall upon the side track B N, distant 13 feet ii^om the main tr
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Keywords: ., bookcentury1800, bookdecade1850, booksubjectenginee, bookyear1856
