Laserfiche WebLink
$ S 1S -S o°601 <br />yZn , as / 5 *50 ,/ffa <br />¢S^68 LU ¢- / 7 <br />2- <br />1-14- <br />1-14- 070 / 7 8 <br />32- <br />77-117 <br />`�SjO��O <br />s'-I32 <br />�,bI-4 /Iq ¢o1 710 ro4-+ "a--1114% <br />_ ;` <br />w (:rv'' C -,w• rh m <br />N�,, 39,gZ <br />CURVE TABLES <br />Published by KEUFFEL & ESSER CO. <br />HOW TO USE CURVE TABLES <br />Table I. contains Tangents and Externals to a I' cure e., 'Iati. to d <br />Ext. to any other radius may be found nearly enough, by dividing the Tan. § {s <br />I 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 />.I: Divide Tan. opposite the given Central Angle by the given Tangent. <br />Y' 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 />be the Nat. Tan. or Nat. Ex. Sec. <br />EXAMPLE Ir . <br />Wanted a Curve with an Ext. of about 12 ft. Angle <br />of Intersection or I. P.=23* 20' to the R. at Station <br />If 542-72. <br />t Ext. in Tab. I opposite 23° 20'= 120.87 C3 <br />120.8712=10.07. Say a 10° Curve. <br />v4 <br />��. Tan. in Tab. I opp. 23° 20'= 1183.1 - <br />1.183.1=10 =118.31. <br />Correction for A. 23° 20' for a 10° Cur. =0.16 4S. i <br />118.31-}-0.16 =118.47 =corrected Tangent. r o <br />(If corrected Ext. is required find in same way) o <br />Ang. 23° 20'=23.33 x -10=2.3333=L.' C. GG <br />2° 1912'=def . for sta. 542 1. P. =sta. 542+72 <br />4° 4912'= " " " +50 Tan. = 1 .18.4p t� <br />70 19#'= " " " 543 <br />9° 491'= " "B. B• C. sta. 541+53.53 ra—Yz" <br />L. C. = 2 .33.33 <br />110 40'— " " " 543+ <br />86.86 E. C. =Sta. 543+86.86 '2• <br />100-53.53=46.47X3'(def. for 1 ft. of 10° Cur.) =139.41'= ZI 4- <br />2° 192" def. for sta. 542. + <br />Def. for 50 ft. =2° 30' for a 10° Curve. _ar <br />Def. for 36.86 ft. =1° 50#' for a 10° Curve. /o'r aQf <br />x <br />�� IRAn9.23.20' 'Me 0v�.. <br />' 'fl <br />N.rn At <br />�D• curve � <br />'sem <br />A/ <br />