Model Tests on Contrarotating Propellers 



screw. These forces are practically constant both in quantity and in direction 

 for the contrarotating propellers. 



• When stopping a ship with steam turbine machinery, the head reaches 

 corresponding to the conventional and the contrarotating propeller are nearly 

 equal. For a ship with Diesel machinery the application of a contrarotating 

 propeller leads to a decrease in head reach. 



ACKNOWLEDGMENTS 



This investigation was carried out under the auspices of the Royal Nether- 

 lands Navy, the shipyards that make up the Netherlands United Shipbuilding 

 Bureaux, Ltd., and Lips N. V. Propeller Works. The permission for the publi- 

 cation of the results of these investigations is gratefully acknowledged. We wish 

 to express our appreciation to Mr. J. auf'm Keller for his valuable assistance 

 in designing the contrarotating propeller series. 



REFERENCES 



1. Hadler, J.B., Morgan, W.B. and Meyers, K.A., "Advanced Propeller Pro- 

 pulsion for High-Powered Single-Screw Ships," Trans. SNAME, 1964 



2. Lindgren, H., Jung, I., and Hillander, H., "Contra-rotating Propellers," 

 "Analysis and Overall Arrangement," Stal-Laval, Technical Information 

 Letter 5/67, 1967 



3. Glover, E.J., "Contra-rotating Propellers for High Speed Cargo Vessels: 

 A Theoretical Design Study," Trans. NECI, 1966-1967 



4. Auf 'm Keller, W.H., "Comparative Tests with Various Propellers for a 

 Tanker and for a Cargo Liner," NSMB Towing Tank Test Report 217, June 

 1965 



5. Esveldt, J., "Comparative Tests with Various Propellers for a Tanker and 

 for a Cargo Liner," NSMB Cavitation Tunnel Test Report 615, June 1965 



6. Wereldsma, J, "Investigation into the Propeller Excited Vibratory Forces 

 for Various Propulsion Devices," NSMB Report 67-2 10- AS, July 1968 



7. Hooft, J. P., "Onderzoek naar de Stopeigenschappen van drie Soorten Voort- 

 stuwers," NSMB Report 66-021-BT, Apr. 1966 



8. Hooft, J. P., and Manen, J.D. van, "The Effect of Propeller Type on the 

 Stopping Abilities of Large Ships," RINA 1967; De Ingenieur, 1967; Intern. 

 Shipb. Progr., 1967 



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