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~� 2 1 G CURVE AND REDUCTION TABLES <br /> j ��` .7.5� $•G S cj���S Publfthed by sugene Distagen Co. <br /> I1 C. <br /> 1 <br /> 73 ' <br /> aysv>s tog <br /> I <br /> 381 �•/. 1. Radius R= 50 <br /> sin D/2 50 <br /> 2. Degree of Curve: D=100 L Also,sin D/2= <br /> 7 <br /> 6 Tfes�l°Dune <br /> 3. Tangent T=R tan%I. Also,T= +C. <br /> 4 Length of Curve: L=100 D <br /> q,Z 7 y� 5. Long Chord L. C.=211 sin I. <br /> ® c 6. Middle Ordinate: M=R (1—cos I) <br /> 7. External E=cos.1/z I—R. Also, E=T tan Y4 I. <br /> 8l'7 r1 S� r� 4v SB EXPLANATION AND USE OF TABLISS <br /> Given P.I.Sta.� 93+40.7,1-46*20'and D=6°30'find: <br /> p 1 fltations—P.C.-P.I.—T. T=T for 1°Curve <br /> D + C. From Tablet V and VI <br /> U M L Lr •�L 7 3 8 Z <br /> T-2398'8+.197-368.32-3+6822.6. Sts. P. C.-83+40.7—(3+68.32)-79+72.3s. <br /> ' P.T.-P.C.+L,and L=100 I100 4b==897.38 Therefore,P.T.=(79+72.38) <br /> B 33 <br /> M�'1 I y � y, `f`�1 �. i f��t./ � +(8+97.38)-86+69.76. � 615 <br /> OIIasLe--Taagent =" v,- <br /> Taby (s�prorimstely) directly with D and �[th the <br /> J square of the distwoe.From III Tangont off. for 100 feet=5.8A9 fest.Diems <br /> / 7 27.62 <br /> =80—Sts.P.C.-27.62.Hence offset+5.66(X(1W)'-.432 ft.Also,square of any <br /> T �' `� �f 3. ` -�(i - distance, <br /> i curve. dividehus Z tw twice <br /> X881.95)equals ftp proximately)the distance from tangent <br /> to Defections—Deflection angle—%D for 100 ft.,X D for 50 ft.,etc.For"X"ft., <br /> t}� c 'i 8 0'7 Deflection Xtion Angle <br /> lb(in <br /> b3.88u L L•'3eXZ XD.For$ta.80 of above curve Deflection Angle <br /> Angle=dfl.for l.ft.from Table III XX—1.95 <br /> 7 P i•�c t�° 31 �,b ry y y,o y X 27.62—53.88'. For Sta.181 Deflection Angle=53.86'+6'2 0'd=4°8.861. <br /> lcatern"s—From Table V for 1°curve,with central angle of 45'20',E=479.6. <br /> Therefore,for 6'30'curve,E 78 be+Correction from Table VI=7.378+.039-7.417. <br /> 9.3a 1 <br />