10 



o After Towpoint 

 X Forward Towpoinf 







A 









J 



'/ 







y 



V 





-«^ 



u 



<^ 







2 4 6 



Speed In knots 



Figure 7a - 100-Poimd Weight 



After Towpoint 

 X Forward Towpoint 







A 









J 



/ 







J' 



y 







U' 







2 4 6 1 



Speed in itnots 



Figure 7b - 75-Pound Weight 



After Towpoint 

 X Forward Towpoint 

















X 







„^ 



y 



/^ 



«rff=«^ 



^ 



y 







After Towpoinf 

 X Forward Towpoint 

















^^' 







f. 



^ 



^'-'" 



-«dS^ 



U 



^ 



<" 





10 



4 6 



Speed in knots 



Speed in knots 



Figure 7o - 50-Found Weight Figxire 7d - 25-Pouiid Weight 



Figure 7 - Drag Characteristics of Faired Weights 



weights are shown in Figure 7. The T 00-pound and 75-pound weights were each 

 towed with 6.0 feet of flexible aircraft cable, l/8 inch in diameter; the 50- 

 pound and 25-pound weights were each towed with 6.0 feet of cable, 1/16 inch 

 in diameter. The corresponding loading curves are shown in Figure 8. 



The characteristics of the TMB planing float were obtained in the 

 manner illustrated in Figure 9. The line used for towing the system was se- 

 cured to the towing carriage dynamometer at the center of a protractor. The 

 drag of the system and the inclination of the towline at the protractor were 

 measured over a range of speeds and with the various faired-weight loading 

 conditions. Since the shape and orientation of the line towing the weight 

 remains the same for a given length and size of line at each speed, the 

 weight calibrations could be used directly. The drag D of the float, then, 



