Ducted and Contrarotating Propellers on Merchant Ships 



Fig. D3 - View of stern of tanker with non-cylindrical ducted propeller 



Finally, it may be noted that application of the noncylindrical ducted propel- 

 ler also offers a means of improving the propulsion characteristics of already 

 existing ships without expensive alterations of the hull shape. There is no doubt 

 that further work on noncylindrical ducted propellers for tankers is of utmost 

 importance. 



1307 



