192 THE PROBLEM OF THE HULL AND ITS SCREW PROPELLER. 
Surface Performance. 
Revs. 
pee A call le “ By, NASI | aes | S : 
Est. | Actual 
05 152 8.44 | .404 ] -1.355 1 198 +1.043 | .125 | .0609 | 145.7 | 145 
.075 | 228} 9.57] .458} 1.1715 | 1 302 +.89 .125 | .0654 | 166 166 
.10 304 | 10.5 | .502 | -1.0414 | 1 408 +.77 .125 | .0669 | 182.5 | 182.5 
15 456 | 11.86 | .567 | -— .858 | 1 623 +.62 .125 | .0723 | 207.3 | 207.5 
.20 608 | 13.05 | .624 | - .7279 | 1 840 +.497 | .125 | .0735 | 228.4 | 228 
.30 912 | 14.87 | .711 | - .5445]} 1] 1281 +.335 | .125 | .0772 | 261.3 | 258.5 
40 1216 | 16.14) .772 | - .4144}1] 1729 +.233 | .125 | .0823 | 285.2 | 281.5 
.50 1520 | 17.3 | .827] - .3135 | 1] 2181 +.154 | .125 | .0866 | 307.1 | 303.2 
.60 | 1824] 18.5 | .885] - .231 | 1] 2637 +.070 | .125 | .0863 | 328.3 | 328 
.70 | 2128 | 19.36 | .926 | — .1613 | 1 | 3096 +.019 | .125 | .0901 | 345 347 
.80 | 2432 | 20 .957 | — .1009 | 1] 3558 +.0 .125 | .0991 | 359.9 | 363 
.90 | 2736 | 20.5 | .980} - .0477 | 1] 4022 +.0 .125 | .112 | 374.3 | 375 
Submerged Condition. 
Revs. 
eae Seal 6 2 hy) | Fe STB || eee 5 $ 
Est. Actual 
+1.84 | .125 | .1862 | 100.6 | 102 
+1.575 | .125 | .2075 | 131.8 | 129 
+1.4 .125 | .2116 | 150.7 | 146 
+1.275 | .125 | .2141 | 166.3 | 161 
+1.09 .125 | .2133 | 190.8 | 184 
+ .95 .125 | .2085 | 210.2 | 203 
+ .76 .125 | .2053 | 241.8 | 235.5 
+ .622 | .125 | .2016 | 267.1 | 262 
.075 228 
Unfortunately, in the case of this vessel no measure of shaft horse-power on 
the surface was taken, the vessel being driven by Diesel engines. In the submerged 
condition electric motors were the propelling units. Attention is called to the 
extremely close agreement between estimated and actual revolutions, the slips 
not, as yet, having changed their character from those of the first to those of the 
second order. In the submerged condition the actual powers were obtained by 
measurements of electric input and voltage to the motors and the resulting K. W. 
