ADJUSTMENT PROCEDURE 



55 



them, they should be kept at an appropriate distance until one or 

 more is actually to be inserted into the binnacle. 



86. Adjustment procedures at sea. — Before proceeding with the 

 adjustment at sea the following precautions should be observed: 



(1) Secure all effective magnetic gear in the normal sea -going 

 position. 



(2) Make sure the degaussing coils are secured, using the 

 reversal sequence, if necessary. 



The adjustments are made with the ship on an even keel, swinging 

 from heading to heading slowly, and after steadying on each heading 

 Chapter V discusses methods of placing a ship on the desired heading. 



87. Most adjustments can be made by trial and error, or by routine 

 procedure such as the one presented in chapter I. However, it is 

 more desirable to follow some analytical procedure whereby the ad- 

 juster is always aware of the magnitude of the errors on all headings 

 as a result of his movement of the different correctors. Two such 

 methods are presented : 



(1) A complete deviation curve can be taken for any given 

 condition, and an estimate made of all the approximate coeffi- 

 cients. See chapter IV for methods of making such estimates. 

 From this estimate, the approximate coefficients are established 

 and the appropriate corrections are made with reasonable cer- 

 tainty on a minimum number of headings. If the original de- 

 viation curve has deviations greater than 20°, rough adjustments 

 should be made on two adjacent cardinal headings before record- 

 ing curve data for such analysis. The mechanics of applying 

 correctors are presented in figure 1. A method of tabulating the 

 anticipated deviations after each correction is illustrated in figure 

 28. The deviation curve used for illustration is the one which was 

 analyzed in chapter IV. Analysis revealed these coefficients : 



A= 1.0°E. 6'=8.0°E. ^=1.5°E. 

 5=12.0°E. Z> = 5.0°E. 



FiGURB 28. — Tabulating anticipated deviations — Analysis method. 



