88 NAUTICAL CHART MANUAL 



Plot the intercepts from the tables (or tab runs), labeling each point with a small circle 

 in colored pencU, preferably that color in which the rate is to be printed. Frequently it wUl 

 be necessary to interpolate to obtain points for intermediate lines of position. Both tables 

 and N.0.0. tab runs provide "delta values" (the column headed by "A"), which are actually 

 tenths of a minute of arc expressed as whole numbers. The algebraic sign preceding the delta 

 value indicates whether it is to be added to or subtracted from the intercept next preceding, 

 to obtain a new intercept midway between the full values. 



After all rates are plotted on the single sheet of stable-base plastic, like points are con- 

 nected by fine black lines. All necessary type is added as determined by the study above, 

 as well as a linear interpolator that best fits the more usable intervals of lines of position. 



Colored overlays shall be prepared one for each color in which loran information is to be 

 printed, and each overlay shall show clearly what information is to be printed in each color. 



AH notes pertaining to loran in general, as well as the linear interpolator, shall be added 

 to the black Drawing, to be printed in black. 



When one of the loran rates is printed in magenta, all compass roses shaU be printed in 

 black. 



All loran lines of position, including base-line extensions, shaU be engraved 0.004" wide. 



Loran lines of position shall be broken only for type of the same color, for all sky wave 

 corrections, and for ocean station vessels. Black information shall not be broken for loran 

 information; neither shaU loran information be broken for black information. Avoid placing 

 loran type where it wiU be obscured by the black. 



After verification, the loran Drawings with type and the overlays are ready for reproduction. 



A consol radio station is a directional radio beacon. The bearing lines radiating from the 

 station are great circle lines of position identifiable to the mariner by a separate count of dots 

 and dashes. The navigator determines his bearing from a station by a count; the intersection 

 of bearings from two stations provides a fix. Consol may be used in conjunction with one or 

 more of the established methods of navigation. 



Control points for consol bearing lines are computed as geographic positions either by 

 the cartographer, or submitted as tab runs from the electronic computer. On a reverse blue- 

 hne of the black negatives, plot first the geographic position of the consol station, then plot 

 the remaining geographic positions of the bearing lines. Connect like points with smooth 

 curves in pencil only. 



Using the consol station as a center, ink in arcs of concentric circles to include all of the 

 pencilled bearings and space the several arcs uniformly five or six inches apart. The inter- 

 sections of the pencilled bearing lines and the arcs shall be shown by short ticks inked on the 

 inside of each arc; intermediate points for bearings may be computed as necessary, or they may 

 be added by graphically subdividing the circular distance. 



