Field-book for railroad engineers. Containing formulas for laying out curves, determining frog angles, levelling, calculating earth-work, etc., etc., together with tables of radii, ordinates deflections, long chords, magnetic variation, logarithms, logarithmic and natural sines, tangents, etc., etc (1877)
Henck, John Benjamin, 1816-1903 · New York : D. Appleton · leaf 40
; whence 2 R sin. D B L = B D — 2 R sm .R> BD 2 sin. DBL — R. When the point D falls on the other side of A, that is, when theangle B is greater than jl, the solution is the same, except that themgle DAB is then 180° — ^(A -\- B), and the angle DBL= B —ABD. REVERSED CURVES. 21 39. Probloiia.… … T- Solution. By § 4 wc have DC = R tan. | /, and CG= Rtan. | /.whence R (tan. ^ / + tan. hi) = D C -{- C G = a, or R = tan. ^ / + ti^n- k ^This formula may be adapted to calculation by logarithms; for we have (Tab. X. 35) tan. ^7+ tm.^P = ^T.^^jcot fj- Substitutingthis value, we get rw R - «gos.…
Railroad engineering · Ferrovias
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