. Transition curves. A field book for engineers, containing rules and tables for laying out transition curves . Fig. 1^ 8 with the tangent is the departure of thevarious points of compound curves. For example let us refer to Table I.,which begins with a 0° 10 curve andcompounds into a sharper curve at the endof each chord, the degree of curve chang-ing to 0° 20, 0° 30, 0° 4:0, etc. See Fig. 2. 5|-l o •ts y 09 s Ml o o ft 10 0° 10 20 0° 20 30 0° 30 40 0° 40 50 0° 50 Angle ofchord. 0° 0 300° 2 000° 4 300° 8 000° 12 30 CosinexlO. SinexlO. Co-ordinates Lati- I Depar-tude. I ture.
. Transition curves. A field book for engineers, containing rules and tables for laying out transition curves . Fig. 1^ 8 with the tangent is the departure of thevarious points of compound curves. For example let us refer to Table I.,which begins with a 0° 10 curve andcompounds into a sharper curve at the endof each chord, the degree of curve chang-ing to 0° 20, 0° 30, 0° 4:0, etc. See Fig. 2. 5|-l o •ts y 09 s Ml o o ft 10 0° 10 20 0° 20 30 0° 30 40 0° 40 50 0° 50 Angle ofchord. 0° 0 300° 2 000° 4 300° 8 000° 12 30 CosinexlO. SinexlO. Co-ordinates Lati- I Depar-tude. I ture. I ! , I ;, Havins: calculated the co-ordinates ofthe different points the deflection angleswere determined by - = tan. Example: To find the deflection anglefor the first point in Table I. 9. T ig. 2. 10 Dep., log. —, log. Ans. .Del angle, 0° 0 80 log. tan. The difference in the degree of curvebetween the different arcs of the transitioncurve should be maintained as nearly aspossible between the terminating arc andthe circular curve. In the field the transit should be placedat T and the angles deflected from thetangent. In case there sliould be an ob-stacle making a point invisible at T, thenext point should be measured on the long-chord. The intermediate j^oint can thenbe easily set. To find the length of the long chord toany point on a cui*ve, Fig. 3. Let C be the length of chord, L thelatitude of the point, and A the deflectionangle. COS AExample: To find the length of the long chord tothe 8th point of the curve in Table III. 11
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishernewyorkdvannostran
