35 



|*-0.854d-^ 



1— nr 



Coordinates 



of Hull Form 



x/d 



y/d 











0.1441 



0.521 



0.2882 



0.727 



0.5764 



0.905 



0.8646 



0.986 



1.1528 



1.000 



1.4410 



0.978 



1.7292 



0.920 



2.0174 



0.832 



2.3056 



0.772 



2.5938 



0.582 



2.8820 



0.434 



3.1702 



0.265 



3.4584 



0.0993 



Towpolnt- 



0.95d— ^ 

 0.00445d 

 0.0897d 



Figure 28 - Dimensioned Sketch of TMB Displacement Float 



All dimensions are referred to the maximum diameter d. 



A drawing of the TMB displacement float In which all of the dimen- 

 sions are referred to the maximum diameter is shown in Figure 28. A photo- 

 graph of the test model is shown in 

 Figure 29. This model was 48.6 inch- 

 es long and lU.05 inches in diameter 

 at its maximum diameter. The hull 

 was constructed of balsa wood,* and 

 all fittings were made of sheet 

 brass . The model weighed 36 pounds 

 and had a reserve buoyancy of 135 

 pounds . 



The elevators providing 

 downward lift at the stern were de- 

 signed for two specific purposes. 

 At low speeds, the pressure distri- 

 bution around the hull produces a 

 downward component of force which 

 tends to make the float trim by the 



Figure 29 - TMB Displacement Float 



This float is an experimental model showing the 

 final positions of the elevators and the towpoint 

 selected for optimum performance. The elevators 

 are set at zero degrees. All dimensions and the 

 position of the towpoint correspond to Figure 28. 



* For a discussion of the methods of construction and waterproofing of the balsa-wood hull, see Appen- 

 dix /^. 



