110 JOINT DISCUSSION ON TWO PRECEDING PAPERS. 
TABLE 1.—Comparison of Propulsive Efficiencies for High and Low Positions. 
Position Low High 
h -94 1.12 
w 22 43 
Case r 
8.94 8.4 
Y 48 .61 
a 226 .218 
P, 810 856 
Ey -538 -428 
E, -464 439 
Case 2 
a 8.75 8.67 
Jibs 376 366 
8.94 8.25 
ys -48 602 
in . 266 .212 
E, 538 -438 
EB, 464 452 
Case 3 
Vv 8.30 8.70 
ff, 322 370 
S -463 -588 
249 213 
je , 710 818 
E, -525 .440 
\‘- EB. 454 -452 
TaBLE 2.—Symobols. 
hk = hull efficiency. 
zw = wake fraction. 
P = pitch in feet. 
S, = effective slip ratio as defined by Froude. 
S, = apparent slip ratio. 
P, = shaft horse-power. 
E, = propeller efficiency in open water. ‘ 
E, = propulsive efficiency of vessel = 17,/ P, 
V = speed of vessel, knots. 
H,, = effective horse-power with appendages under standard test conditions. 
R = revolutions per minute. 
PD = diameter in feet. 
