Laserfiche WebLink
i <br /> FIEM BOOK 534 <br /> + E/,. <br /> CURVE TABLES. <br /> I , <br /> ----- Published by KEUFFEL 86 ESSER CO. <br /> HOW TO USE CURVE TABLES. <br /> — — <br /> Table I. contains Tangents and Externals to a 1°curve. Tan.and <br /> to any other radius may be f ound nearly enough,bydividing the Tan. <br /> Ext.opposite the given Central An le by the given degree of curve. <br /> - - ,_ ___ - _ _-" To find Deg. of Curve, having the Central Angle and Tangent: <br /> de Tan. opposite the given Central Angle by the given Tangent. <br /> -- To find Deg. of Curve, having the Central Angle and External: <br /> - — -- vide 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 /> Ext.of twice the given angle divided by the radius of a 1°curve will <br /> the Nat.Tan.or Nat.Ex.Sec. <br /> - - <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 231 20'=120.87 <br /> o a. <br /> -8 6 /'89 120.87=12=10.07. Say a 10°Curve. <br /> Tan.in Tab. I opp.23°20'=1183.1 <br /> 1183.11-10=118.31. <br /> Correction for A.23°20'for a 10°Cur.=0.16 <br /> 118.31+0.16=118.47=corrected —Tangent. <br /> ��: _ � 4 (If corrected Ext.is r u <br /> ued find in same way) <br /> 7 <br /> Ang.23 20'=23.33 —10=2.3333—L.C. <br /> 2°19;'=def.for sta. 542 I. P.=sta. 542+72 <br /> 40 491'= " " a +50 Tan.= 1 .18.47 <br /> /3_Aff�k_z 83 .� 7°19;x= a a a 543 <br /> o i492 —r— a a a B.C.=sta. 541+53.53 <br /> / 9 +50 <br /> 11°40'= a a a + L.C.= 2 .33.33 <br /> 86.86 E.C.=Sta. 543+86.86 <br /> 4 s' 100-53.53=46.47X3'(def.for 1 ft.of 10°Cur.)=139.41'= <br /> -7 (-o�, ¢ 8 is 2°19;'=def.for sta.542. <br /> -- Def.for 50 ft.=20 30'for a 10°Curve. <br /> /-z-6 IL o a i 4. Def.for 36.86 ft.=10 50"for a 10°Curve. <br /> 4.s <br /> - / ---- 2. LP.An9.23.20' <br /> LY <br /> i <br /> 10*Curve <br /> a <br />