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Ck-- <br /> CURVE AND REDUCTION TABLES <br /> - --- --- --_- -- lnbliahed by Eugene Dietagen Co. <br /> 1 <br /> 1 <br /> 1 <br /> CARVE TORR LAS <br /> ------- ---- - L Radius R= 50 <br /> sin D/2 <br /> -- - - ----- - ------ - 2. Degree of Curve: D=100 L Also,sin D/2=5 <br /> ------- ------ - Tforl'curte <br /> 4. I.e hof Curve: L=100-D 1 � �._ C. <br /> � <br /> — _--- --__ __- 3. Tangent T=R tan I. Also T= + <br /> - t3e /2 <br /> ------ ----- <br /> -- 5. Long Chord : L.C.=2R sin I. <br /> 6. Middle Ordinate: M=R(1-cos I) <br /> __-- -- 7. External E=Cos I-R. Also, E=T tan I. <br /> --- EXPLANATION AND USE OF TABLES <br /> Given P.I.Sts.83+40.7,1-45*20'and D-6'30 find: <br /> T for 1v Curve <br /> stations-P.C.-P.I.-T. T- + C. From Tables>Y and VI <br /> T-23985.8+.197-368.32-8+88.32. Sts. P,,_C.-88+40.7-(3+68.32)-79+72.38. <br /> f, ---- P.T.-P.C.+L,and L+100 V-100 83-697.38 Therefore,P.T,-(79.+72.38) <br /> (6+97.38)-88+69.76. <br /> ---- --— Oiftets'Tangent alo�eo:imatel1) dlreof with`D an4 with the <br /> square of the distance. Taws I nt Offset for 100 f foot-3.689 feet.Distance <br /> -80-814% P.C. .27.62.Hence offeet+lj.88X(27.62100 x.432 it.Alio,oquare of acy <br /> N ----- - , distance,divided by twiaslthe radius pqle((approzimA/eW the distsame from tangent <br /> { / to curve.Thus( . f+(2X881.95)-.'432 ft. <br /> — _ d Deflections-Deflection angle-3§D for 100 ft.,X D for 50 ft.,etc.For"X"ft., <br /> Deflection Angle(in minutes)-.3 XX XD.For 9ta.80 of above curve Deflection Angle <br /> � > -.3 X27.62 X6.5-53.86.Also Deflectioa Angle-dfl.for 1 ft.from Table III XX-1.95 <br /> v <br /> S X27.62-53.86'.'For 914L 181 Deflection Angle-53.86'-f-6 2-4°8.86'. <br /> =atemah=From T"'V foe 1*curve,with central angle of 45'201,E-479.6. <br /> _ 479.6 <br /> Therefore,for 6'30'eerve,lk-- ++C rreotiaa from fable YI-7.378+.009'•7.417. <br /> 1 i <br /> f <br />