Laserfiche WebLink
f <br />i; <br />5 <br />rI J Z Z b 4 <br />e, 27 <br />CURVE TABLES. Q "4, <br />Q. a—- - <br />Published by KEUFFEL & ESSER C0. -------- <br />S <br />l <br />_. <br />HOW TO USE CURVE TABLES,._z_'�-- <br />Table I. contains Tangents and Externals to a 1° curve. Tan. and <br />Ext. to any other radius may be found nearly enough, by dividing theTan. <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 />1 <br />' <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. See. <br />r <br />EXAMPLE. <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 />542+72. <br />Ext. in Tab. I opposite 23° 20' =120.87 <br />;g? <br />p",1p <br />1 <br />!► <br />' I t <br />i 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 />Correction for A. 23° 20' for a.10° Cur. =0.16 <br />118.31+0.16 =118.47 =corrected Tangent. S <br />(If corrected Exi. is required find in same way) <br />Ang.23°20'=23.33*=10=2.3333=L.C. $--- <br />2°19"=def. for sta. 542 I.P.=sta. 542-1-72 :S7 -,&T <br />40 49V _ 'r +50 Tan. = 1 .18.47 -7 , a <br />1 <br />1 <br />70 192' = " 543 B. C. = sta _ 541 +53.53 <br />90 492'= u �: « +50 <br />110 40' _ `: It543 L. C. = 3 .33.33�a <br />86.86 E. C.=Sta. 543+S6.86 56.86 f 2� 47 <br />100-53.53=46.47X3'(dcf. for 1 ft. of 10° Cur.)=139.41'= -,,&�.C. <br />1' <br />� <br />^ <br />2° 192'=def. for sta. 542. i? <br />Def. for 50 ft. =2° 30' for a 10° Curve. <br />Def. for 36.56 ft. =1° 502' for a 10° Curve. ` <br />s )9,s9 <br />4 <br />�% 4OII <br />>2 <br />` <br />10• curve <br />%i <br />is i--� <br />� �` • Qo � E. Z 7 <br />