Sec. 60.6 



SHIP-POWERING DATA 



361 



ELEVATION OF PORT SIDE 

 LOOKING FORWARD 



R' 8.2 ft 

 Propeller Tip Circle^-.^^ A-J^i^lZ?--^ IT^S 



Values for 

 Circles Shown 

 with Broken Lines 

 ore Extrapolated 



Fig. 60.D Wake-Survey Diagram for a Twin-Screw Naval Vessel, U.S.S. Terror 



head pitot tube, are reproduced in Fig. ll.F of 

 Part 1 and Figs. 60. D througli 60. J of the present 

 section. The diagram of Fig. 60. D is for a wing 

 propeller position on a twin-screw stern of noi'mal 

 form, while those of Figs. 60. E through 60. H are 

 for single-screw sterns with centerline skegs, 

 representing variations of the U. S. Maritime 

 Administration C4-S-la or Mariner class. Numeri- 

 cal data pertaining to these five are listed in 

 Table 60.b. The diagrams of Figs. 60.1 and 60.J, 

 adapted from Figs. 32 and 33 of a paper by H. R. 

 Neifert and J. H. Robinson [SNAME, 1955, pp. 

 525-526], are for the light and intermediate load 

 conditions, respectively, of a model of the Victory 

 ship Lt. James E. Robinson. 



Fig. 60. K, for comparison, depicts the wake 

 situation at the tail of a torpedo, in the form of a 

 body of revolution but with two vertical and two 

 horizontal fins ahead of the propeller positions. 



Fig. 60. M of Sec. 60.7 is a wake-survey diagram 

 for the propeller position on the transom-stern 

 ABC ship which is designed and described in 

 Part 4. 



Diagrams such as those listed in the foregoing, 

 which carry a multitude of survey points, may 

 become cluttered up and confusing if they include 

 the section lines for the portion of .the afterbody 

 or run just forward of the propeller position. 

 These section lines, however, are important 

 features in the wake analysis because they show 

 the shape of the ship just ahead of the propeller 

 position. For a comprehensive analysis they 

 should be available on or with the wake-survey 

 diagram, drawn preferably to the same scale. 



Appended is a partial list of additional 3-diml 

 wake-survey diagrams of the TMB type, as 

 published in the technical literature: 



(a) Twin-skeg Manhattan design; wake over propeller 



disc abaft skeg and for considerable distance beyond; 

 SNAME, 1947, Fig. 22, p. 115 



(b) U. S. Maritime Commission, C-3 cargo vessel, TMB 



model 3534; SNAME, 1947, Fig. 45, p. 146 



(c) U. S. Maritime Commission design for a transatlantic 



liner, TMB model 3917; SNAME, 1947, Fig. 58, 

 p. 151 



(d) U. S. Maritime Administration Mariner design, 



"closed stern," TMB Model 4358W-1; SNAME, 



