. The trackman's helper, a handbook for track foremen, supervisors and engineers . /2 30 396 3 2 12 77/16 25 27^ 15 383 3 3^16 13 0% 26 11/4 30 371 3 4% 13 51^16 26 11% 16 359 3 5i%e 13 11 27 10 /- 30 348 3 71/4 14 4^16 28 8% 17 338 3 8% 14 93^ 29 6% 18 320 3 111/4 15 7% 31 37/16 19 303 4 1% 16 6I/16 33 01/^ 20 288 4 41/2 17 4% 34 83/4 21 274 4 71/^ 18 2II/16 36 5% 22 262 4 93/4 19 1 38 2 23 251 5 oyi6 19 111/4 39 101/2 24 240 5 31/16 20 91/2 41 7 25 231 5 5% 21 7% 43 31/2 223 224 THE TRACKMANS HELPER number of degrees in the angle I C D, expresses thedegree of the curve when the chord is 100
. The trackman's helper, a handbook for track foremen, supervisors and engineers . /2 30 396 3 2 12 77/16 25 27^ 15 383 3 3^16 13 0% 26 11/4 30 371 3 4% 13 51^16 26 11% 16 359 3 5i%e 13 11 27 10 /- 30 348 3 71/4 14 4^16 28 8% 17 338 3 8% 14 93^ 29 6% 18 320 3 111/4 15 7% 31 37/16 19 303 4 1% 16 6I/16 33 01/^ 20 288 4 41/2 17 4% 34 83/4 21 274 4 71/^ 18 2II/16 36 5% 22 262 4 93/4 19 1 38 2 23 251 5 oyi6 19 111/4 39 101/2 24 240 5 31/16 20 91/2 41 7 25 231 5 5% 21 7% 43 31/2 223 224 THE TRACKMANS HELPER number of degrees in the angle I C D, expresses thedegree of the curve when the chord is 100 ft. In the table of Radii, ordinates for a curve contain-ing odd minutes can be readily calculated by simpleproportion. Having these respective distances, anyintelligent foreman can trace a curve on the groundwith tolerable accuracy, especially where the groundis favorable. Suppose it be required to lay out in this manner, afour degree curve:—First, find from the table thetangent deflection, H C, corresponding to a four-de-gree curve, viz, 3 feet 5% inches, and also the chord. Fig. 43. Elements of Railroad Curve deflection, I D, or K E, 6 feet ll^ inches. Then fromthe starting point, B, and in line with A B, measure BH, equal to 100 feet, and mark the point H. Swingthe tape around toward B C, keeping the end at Bfixed, at the same time measure from the point H thetangent deflection 3 feet 5% inches, and place astake at C for the first point on the curve. Thenmake C I equal to 100 feet, putting a peg at I, in linewith those at B and C. Swing the tape around untilI D is equal to the chord deflection, 6 feet 11% a stake at D for the second point on the the same manner continue the chord deflectionuntil the end of the curve is reached at E. LAYING OUT CURVES 225 In order to pass from the curve at E to the nexttangent, E G, make E L equal to 100 feet, and put in apeg at L in line with those at D and E. Swing thetape around until F L is equal to the tangent de
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