Fully Cavitating Propeller for a Hydrofoil Ship 



Fig. 28 - Comparison of thrust between bronze and 

 epoxy resin models — screw T95 



had to be thin to avoid changing the blade shape and increasing the structural 

 stiffness. At the same time the leads could not be let into the blades, as this 

 would also have altered the local structural stiffness. 



Considerable difficulty was experienced in maintaining a high resistance 

 between the gauges the blade wiring and the tunnel water, and after a relatively 

 short period of immersion this resistance began to fall. It became necessary 

 therefore to halt the experiments after the earth resistance had fallen appreci- 

 ably and allow time for the equipment to dry out before proceeding. This diffi- 

 culty, on top of the initial waterproofing problems, made these experiments very 

 time-consuming and it became necessary to restrict the scope of the measure- 

 ments to the gauges situated at the 20 percent chord position only. 



997 



