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--- - CURVE TABLES.n - --- -- Published by IM FEL & PSBR CO. - --- HOW TO USE CURVE TABIM. ---_ Table I. contains Tangents and Externals to a P curve. Tan. and to any other radius may be found nearly enough, by dividing theTan. -- - . - - -- Exto pcaRe the given Central An le by the iven degree of curve. opp To find Deg. having t�e Centra Angle and Tangent: 3 - of .Curve, !Inde Tan. opposite the given Central Angle by the given Tangent. To find Deg. of Curve, having the Central Ankle and External: hide Ext. opposite the given Central Angle by the given External. To find Nat. Tan. Nat. Ex. Sec. for angle by Table I.: Tan. ' and any -Ext. of twice the given an le divided by the radius of a 10 curve will be the Nat. Tan. or Nat Ex. Sec. - - EX"PLE. Wanted a Curve with an Ext. of about 12 ft. Angle of Intersection or I. P. -230 20' to the R. at Station � _ _ __ ., , b42♦72. Ext: in Tab. I o 23' 20' =120.87 It 4. 120.87-t-12-1r�Say a l0• Curve. iasy Tan. in Tab. I opp 23.20'= 1183.1 1183.1+10=118.31. r J, Z Correction for A. 23° 20' for a 10° Cur. 118:31 -1 -0.16¢118.47 -corrected Tangent. - L • ✓ __ ( (If corrected Ext. is required find in same way) 3 �� Ang.23°20'=23.33?-10=2.3333-L. C. Z- i�- _ _ 2a OF -def. for sta. 542 I. P.=sta. 542+72 6 4' 49+}' - a a s +50 Tan.— 1 .18.47 9e49'- a a a B. C. -stn. 541-1-53.53 ` . r) J. -- 11044= a a a� L. C.a 2 .33.33 - �'� -- _ - -- 14.1. 9_3 / •✓ 86.86 E. C.-Sta. 543-1-86.86 100.-53.53-46.47X3'(def. for 1 ft. of 10° Cur.) =139.41'= for 20 191' -def. sta. 542. 4 23' �' J�� ✓_ Def. for 50 ft. -2' 30' for a l0' Curve.' -- - ----- - - - Def. for 36.86 ft. -V 50j' for a 10° �urve. +n - 1�.Z �.d ✓ r* +x �3 i3• ,' 1.1 ,/ .. P,brg.ti•i0' � .: Im corn , �``a it � P • ar