. American engineer and railroad journal . + i g - g)=^ s - {R + ig) = 3-4568865 R + ^ g — g = ar. comp. A + i]?- = 766 T94 ar. comp. .. 156612 sq. root 2) i B A C= 87° 50 45 sin. whence the angle B A C = 175° 41 30 and the angleD A E = 180° — 175° 41 30 = 4° 18 30, the requiredanswer. CASE 11. We will now consider the case where the main trackcurve IS to the right, with the turnout curve to the left,with the third rail on the left of the center, as shown infig. 22. In a similar manner to that employed in Case
. American engineer and railroad journal . + i g - g)=^ s - {R + ig) = 3-4568865 R + ^ g — g = ar. comp. A + i]?- = 766 T94 ar. comp. .. 156612 sq. root 2) i B A C= 87° 50 45 sin. whence the angle B A C = 175° 41 30 and the angleD A E = 180° — 175° 41 30 = 4° 18 30, the requiredanswer. CASE 11. We will now consider the case where the main trackcurve IS to the right, with the turnout curve to the left,with the third rail on the left of the center, as shown infig. 22. In a similar manner to that employed in Case I., it maybe shown that the frog angle D A E = A B C + yl C B,and also, as in this case, for convenience, we at once cal-culate the angle 7! A Cand find D A E = 180° — B A C. To find the first frog angle DAE, fig. 22, given theradius of the main track = A, the radius of the turnoutcurve = A, and the standard gauge = g. In the triangle B A C there are given B A = R + i g,A C = R + ig and B C = R + R, to find the angleB A ^ = 4 ft. 8i in. = , and the narrow gauge_^ = 3 ft.,to find the frog angle DAE, fig. 20 : _ (2864 93 + ) + ( -I- ) + ( — + 3 °°) „ 36, J _ (/? 4. ^ §■) - s -(R - \g + _«-■) = . 34572434 R ^ \ g = ar. comp R- —\ o + _o- = ar. Extracting sq root 2) \ B A C =iT o8 34 ■ sill. whence the angle B A C= 174 17 oS and the angleDAE= 180^ - 174° 17 08- = 5° 42 52, the requiredanswer. To find the frog angle D A E. fig. 21, of the third ordouble-pointed Irog, given the radius of the main track =R, the radius of the turnout = R , the standard gauge =g, and the narrow gauge = g. In the triangle BA C we have the side B A = R + i g,A C= R + ig - g, B C= R + R. , . (RJrR)+(7i + ig- g) + (R + i g)Letting -f = ^ 2 we have from trigonometry Since these sides are the
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectrailroadengineering
