High Performance Ships—Promises and Problems 19 
DESTROYER 
ESCORT 
COMPLETE WITH NACELLE & 
SONAR , DOME 
ESCORT RESEARCH. SHIP WITH SONAR ME 
BARE HULL 
HORSEPOWER 
Fig. 19. Speed-power curves for an escort research ship and a destroyer 
escort of about the same displacement 
Some Other High-Performance Ships 
Spar Ship—This craft was designed to be an effective and inexpensive sonar ship. The 
principal idea was to submerge the sonar dome as deep as possible on a surface ship. It 
was also desired to have minimum motions. Speed was not an important parameter. These 
ideas led to a ship having a vertical distribution of displacement rather than horizontal 
(see Fig. 20). 
Fig. 20. A spar ship 
