Laserfiche WebLink
CURVE TABLES <br />Published by KEUFFEL & ESSER CO. <br />HOW TO USE CURVE TABLES <br />Table I. contains Tangents and Externals to a V curve. an. and <br />Ext. to any other radius maybe found nearly enough, by dividing the Tan. <br />�.-- <br />or Ext. opposite the given Central Angle by the given degree of curve. <br />To find Deg. of Curve, having the Central Angle and Tangent: <br />Divide Tan. opposite the given Central Angle by the given Tangent. <br />To find Deg. of Curve, having the Central Angle and External: <br />Divide Ext. opposite the given Central Angle by the given External. <br />To find Nat. Tan. and Nat. Ex. Sec. for any angle by Table I.: Tan. <br />or Ext. of twice the given angle divided by the radius of a 1° curve will <br />t <br />-, <br />1 be the Nat. Tan. or Nat. Ex. Sec. <br />�'r , <br />Q'. <br />EXAMPLE <br />Wanted a Curve with an Ext. of about 12 ft. Angle <br />of Intersection or I. P. =230 20' to the R. at Station <br />a <br />542+72. <br />Ext. in Tab. I opposite 230 20' =120.87 <br />-- \� <br />120.87=12=10.07. Say a 10° Curve. <br />Tan. in Tab. I opp. 23° 20'= 1183.1 <br />1183.1=10 =118.31.. <br />- <br />Correction for A. 23° 20' for. a 10° Cur. =0.16 <br />118.31-}-0.16 =118.47 =corrected Tangent. <br />(If corrected Ext. is required find in same way) <br />Ang. 23° 20'=23.33°=10=2.3333=L. C. <br />-- <br />2°19;'=def. for sta. 542 I. P.=sta. 542+72 <br />404911= _ " +50 Tan. = 1 .18.47 <br />. 7° 19"= " « 543 <br />I,— .�, „ « B. C. =sta. 541+53.53 <br />+50 <br />— <br />11440' = a it It 5 3+ L. C. = 2 .33.33 <br />_ <br />86.86 E. C. =Sta. 543+86.86 <br />100-53.53=46.47X31(def. for 1 ft. of 10° Cur.)=139.41'= <br />2° 19T'=def. for sta. 542. <br />Def. for 50 ft. =2° 30' for a 10° Curve. <br />Def. for 36.86 ft. =I' 501,' for a 10° Curve. <br />64 <br />I.P.An9.23-20' <br />3°20' <br />Al 4 <br />` <br />