Table 26 — Comparison of Resistance Results for LCB Series 





Position of 









© Values for 400-ft Ship 









Cb 



LCB as % 



. — Service speed"—- 



• — Trial speed"—- 



— Sustained speed""— - 



—Trial speed'^ 



(Cf) 



Lbp from (2 



® 



© 



® 



© 



® 



© 



® 



© 



0.60 



2.48^ 



2.358 



0.815 



2.515 



0.990 



2.275 



0.750 



2.411 



0.872 





1.50^ 





0.803 





0.983 





0.736 





0.866 



(0.614) 



0.51.4 





0.822 





1.027 





0.754 





0.890 





0.b2F 





0.858 





1.038 





0.785 





0.922 





Optimum 





















LCB&© 



1.69 A 



0.802 



1.80^ 



0.980 



1.65^ 



0.735 



1.73/1 



0.865 



0.65 



2.46^ 



2.046 



0.731 



2.198 



0.763 



2.025 



0.731 



2.146 



0.741 





1.54A 





0.723 





0.766 





0.722 





0.739 



(0.661) 



0.50A 





0.725 





0.778 





0.722 





0.750 





0.38F 





0.745 





0.822 





0.740 





0.781 





1.37F 





0.797 





0.890 





0.788 





0.849 





Optimum 





















LCB & © 



l.OU 



0.722 



2.50^ 



0.763 



0.90^ 



0.720 



1.85^ 



0.740 



0.70 



2.05/1 



1.745 



0.754 



1.896 



0.773 



1.777 



0.759 



1.884 



0.772 





0.55A 





0.726 





0.760 





0.731 





0.757 



(0.710) 



0.50F 





0.728 





0.783 





0.735 





0.778 





1.54F 





743 





0.811 





0.752 





0.803 





2.55F 





0.776 





0.866 





0.790 





0.856 





Optimum 





















LCB & © 



25^ 



0.725 



0.95^ 



0.757 



0.25 A 



0.730 



0.90 A 



0.754 



0.75 



0.48F 



1.463 



0.751 



1 610 



0.777 



1.552 



0.768 



1.645 



0.783 





1.50F 





0.722 





0.765 





0.747 





0.777 



(0.758) 



2.57F 





0.702 





0.773 





0.741 





0.795 





3.46F 





0.720 





0.791 





0.752 





0.823 





Optimum 





















LCB &© 



2.607? 



0.702 



1.70F 



0.764 



2.307=' 



0.741 



1.20F 



0.776 



0.80 



0.76F 



1.190 



0.792 



1.332 



0.806 



1.335 



0.807 



1.415 



0.819 





1A5F 





0.752 





0.768 





0.769 





0.786 



(0.805) 



2.50F 





0.731 





0.739 





0,740 





0.771 





3.51F 





0.736 





0.760 





0.761 





807 





Optimum 





















LCB &© 

 ander Formula [1 



2.70F 



in text. 



730 



2.56;? 



0.739 



2.56F 



0.740 



2.23F 



0.770 



° From Ales 





6 From Troost Formula [2] in 



text. 

















The optimum locations of LCB for Series 60 at the sustained sea speed and trial speed, 

 as defined by Troost, are plotted in Figure 32. If desired, the effect of speed can be brought 

 out by treating it as a parameter for a series of curves such as the two shown. From the cross 

 curves of Figures 26-30, the permissible movement of the LCB forward or aft of the optimum 

 position has been determ.ined in order that the minimum (?) value shall not be exceeded by 

 more than 1 percent. The resultant limits are shown as dotted curves in Figure 32 for both 

 sea and trial speeds. 



It should be noted that all the Series 60 forms have a vertical stem line but no bulb at 

 the forefoot, and that the recommended LCB locations refer to such designs. In the finer 

 forms, it is probable that in many cases a bulb would be fitted which would result in some 

 variation in LCB position, depending upon how much the bulb was treated as an addition or 

 how far the extra displacement was used to fine down the load waterline and forebody 

 generally. 



VI-14 



