THE PROBLEM OF THE HULL AND ITS SCREW PROPELLER. 221 
Analysis Comparison Analysis 
E. H. P. = 3575 LO Tah 2 t= 2) olr(o}e) 3.9722 
S. H. P. = 4726 Sy hep y) — seeien 5.2506 
6 
e. h. p. = 1160 e.h.p. = aa = .007844 .007844 
Gy ldo jOs | e. h. p. -3244 
EEN ec EHP. = paz = 001974 .00197475 
E. H.P. E.H.P 
een uss Ls Ap \ 
'p = 1.0414 Log enna Z, = 1.0414 Log (Gee x R ) 2.8164 
Keo= 1-175 KG neste 1.175 
6 
8. H. P.g = 1716 s.h. p.g = a = .0093944 - .0094156 
v=11 v= aif = 2.0083 2.0083 
Di v j 8 
7 = -7348 == Se = ongying 13417 
Z; = 2.861 Log ({-)--2788=.30400 2. = 2.4170 2.4170 
S = .1024 S = .065442 06558 
R -8316 (qs 
Ra = 84.19 Ke S49 See aa 442.96 
Attention is called to the extremely low load and power fractions under which the 
model screw operates at comparative speeds and loads. Commander McEntee’s esti- 
mates for the ship are 1750 S.H.P.g and 84.5 revolutions. 
Now take another case, beginning with the model screw, and estimate the power 
and revolutions for the ship by comparison and by analysis of the actual propeller. 
Let us take the case of Vessel H. 
Speed of ship = 21 knots. Diam. of Propeller = 18.25’ 
e.h.p. = Tags 7a Pitch of Propeller = 19.75’ 
Propellers ee three bladed |) ae of Propeller = .328 
R = 30 
