54 



5-^.3 Bulbs and Cruiser Sterns 



Actually the sectional-area curves of most present day ships are 

 characterized by a condition t ~ 0, due to the more or less heavy rake of the 

 stem. As long as the rake is small we suppose that its influence on the re- 

 sistance is not large. In such cases, we therefore determine t as though the 

 normal form extended up to the forward perpendicular; the actual rounding off 

 at the stem also tends to compensate the error committed. The resistance cal- 

 culations can thus be performed in the usual way. 



Matters become more complicated for heavily raked stems like the 

 well known Maier form. Here the generating singularities should be distrib- 

 uted within a triangular contour at the bow. Although in principle, calcula- 

 tions of wave resistance do not present difficulties even in this case they 

 become rather tedious, so that the properties of such distributions have not 

 been rigorously investigated. Actually one substitutes a distribution limited 

 by a rectangle, keeping the intensities approximately equal (Figure 30). Even- 

 tually a more elaborate calculation will be made instead of this rather coarse 

















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Figure 30 - Pronounced V-sections at the Bow 



