162 



RAILROAD CURVES 

 TABLE (Continued) 



If Dm is the deflection angle for a chord of 100 ft., then 



sm Moo 

 For a 1 curve, Moo = 30' and R = 5,730, nearly. For curves 



5,730 

 less than 10, the radius may be taken as -- , in which D c is 



DC 



the degree of curvature. The accompanying table gives the 

 length of the radius, in feet, for degrees of curvature ranging 

 by intervals of 5' and 10' from & to 20. 



Tangent Distance. The point where a curve begins is 

 called the point of curve, and is designated by the letters P. C.; 

 and the point where the curve terminates is called the point 

 of tangency, and is designated by the letters P. T. The point 

 of intersection of the tangents is called the point of intersec- 

 tion; it is designated by the letters P. I. 



