formula and as found from the actual model tests for the sustained sea speed defined in 

 Equation [2] compare as follows: 





Cp 



OPTIMUM LCB POSITION 



^'b 



From Equation 3 



From Series 60 Tests 



0.60 



0.614 



1.755A 



1.65A 



0.65 



0.661 



0.933 A 



0.90A 



0.70 



0.710 



0.075A 



0.25A 



0.75 



0.758 



0.765F 



2.30F 



0.80 



0.805 



1.587F 



2.50F 



In comparing Lap's results with Series 60, Troost designed a parent model family of five 

 ships: 





NSMB 



Series 60 



^BP 



400 ft 



400 ft 



L/B 



7.0 



6.5-7.5 



B/H 



2.4 



2.5 



Cx 



0.98 



0.977-0.994 



Cp 



0.80 



0.805 





0.75 



0.758 





0.70 



0.710 





0.65 



0.661 





0.60 



0.614 



In making the resistance comparison, Troost assumed that the finest models of 0.60 C p 

 would have a bulbous bow, and he reduced Lap's estimates for a conventional bow by 

 1 percent for sea speed and 6 percent for trial speed. In order to compare the estimates 

 made from the NSMB family with the results of Series 60, which has no bulb, these allow- 

 ances have been restored. The comparison with Series 60 is now as set out on (iie follow- 

 ing page and shown in Figure 35. 



VI-18 



