Sec. 5S.3 



RUNNING-ATTITUDE DIAGRAMS 



5 



-0.3 



Trim of 

 0.16 Deq b^ Bow at 



Designed Spaed 



Solid Line is for Model Towed Bare Hull 

 BriDken Line is for Model Self-Propelled witli Appendaqes' 



5-0.7 



ABC SHIP TMB Model 4505 



FP Qt Woterllne 

 Beginning at Bow 



.mI,,J L 



T- , V 



I'^.YTi 



1.2 



Fig. 58.B Non-Dimensional Change-of-Trim Data for TMB Model 4505, Representing Transom-Stern 

 ABC Srap, When Towed Bare Hull and When Self-Pkopelled 



Fig. 58.C Non-Dimensional Change-of-Trim Data for TMB Model 4505-1, Representing Arch-Stern 

 ABC Ship, When Towed Bare Hull and When Sblf-Propblled 



level and trim with speed. These are based upon 

 the conclusions previously formulated by D. W. 

 Taylor [S and P, 1943, pp. 72-74], taking account 

 of test data on many models other than the ten 

 listed on page 73 of the reference. So many vari- 

 ables enter the picture, however, that it is difficult, 

 if not impossible to extend them over the entire 

 range in which the marine architect is interested. 

 The modified conclusions, taken with the graphs 

 of Fig. 58. A, enable reasonably precise predictions 

 to be made for the running attitude of vessels 

 not too different from the normal forms: 



(1) For displacement-type vessels, supported 

 primarily by buoyancy, the vertical forces de- 



veloped by changes in hydrostatic pressure in the 

 surface waterline region predominate over those 

 due to Ap's resulting from hydrodynainic action 

 (2) Vessels of the displacement type, having the 

 waterline area concentrated near amidships, and 

 large waterline areas for their length, drop 

 bodily about in proportion to the fineness of 

 their waterline endings and to their displacement- 

 length quotient or fatness ratio. The drop is 

 greater with smaller prismatic coefficients Cp 

 because of the rather direct relationship between 

 Cp and Cw , indicated in Fig. 66.H. For vessels 

 having Cp values less than 0.65, with fine water- 

 line endings and the waterline area well con- 

 centrated amidships, the bodily settlement and 



