Norrbin 



liL 



"^'V/'O 



^-<y 



DC' 



fi.O 



■^13^- 



"o^- 



"o^. 



•^ 



/ 



/ 

 / 



/ ] - 5 00 



> 



A^ 



}• 2 00 



Ml" 



?-/ 



Fig, 38. Rel, change of rotary acceleration moment derivative 

 for a tanker as a function of waterway depth and width, 

 replotted from Fujino PMM data. 



The diagrams in Fig. 35 - 38 are compiled from Fujino's 

 measurements of rotary and acceleration derivatives in shallow 

 waters and in canals. The dotted curves suggest a linear increase 

 of all these derivatives with t, in unrestricted water, and a more 

 complex dependence of Z, and ii in a canal. (Cf, end of Section X. ) 



XIII. SOME ASPECTS OF SPilP BEHAVIOUR IN CONFINED WATERS 



Here a few comments will be given on some of the results 

 obtained in a computer and sinaulator study performed for the 

 98 000 tdw tanker. The diagrams in Figs. 39 - 45 all include results 

 directly drawn on the analogue computer recorder. 



The only full scale maneuvering trials with the prototype 

 ship so far available are a 20°/20° zig-zag test and a Dieudonn^ 

 spiral, both run at fiill speed on full draught. These results are 

 compared with the computer predictions — or hindcasts — for the 

 ship on Suez draught in Figs. 39 and 40. As the difference in draught 

 is not likely to have a significant influence the agreement is quite 

 good. It shall be observed that the derivatives with respect to 



890 



