The Washington herald. [volume] (Washington, D.C.) 1906-1939, 1913-07-06
WARSHIPS' SHAPE DECIDED ON TOY OCEAN,
Important Work in Connection with Construction Of the Big
Dreadnoughts Is Done at $4,000 Testing Basin"
at the Washington Navy Yard

The manner in which naval con-
structors determine on the ultimate
shape of the big dreadnoughts which de-
fend the honor the honor OF the Stars
and Stripes on the ocean is a problem
to which the average layman gives little
or no thought. If he considers the ques-
ton at all he probably thinks that the
shape Of the hull of a warship is de-
ternined by pattern, much as seam
stress would cut a dress. or that the
size Of the vessel bears some connection
with the engines which are to be placed
therein.
In the last assumption he is not far
wrong-the shape of the man O. war
is determined by the speed which the
vessel is expected TO make, but this de-
termination necessitateS numerous in
tricate operations. the handling of many
figures, and. finally, the use Of the only
TOY ocean on this side Of the Atlantic
the 100000 testing basin" at the
Washington Navy Yard.
Properly to understand the principles
underlying the work of the testing basin
and the men who operate 1t one must
go back a few years and consider the
experiments Of Dr. William Froude, a
famous English shipbuilder Of the latter
part of the last century.
Used Pond Near Home.
Dr. Froude was one of the members
of a committee appointed by the British
admiralty TO investigate the relation be-
tween the shape Of war vessels and their
speed. with view to improving the
British Navy. BY towing small planes
and models Of boats over the surface
of his pond at TorQuay, England. and
making careful note of the resistance
which each tiny boat made to the pres
sure of the water, DIR. Froude was en-
dbled definitely to determine a formula
which became the basis OF all shipbuild-
ing and Is responsible for the principle
of the modern testing basins. wherein
ships of all kinds are first tested for
their ultimate construction and shape.
DIR. Froude's experiments showed con-
clusively that the perdetermination Of the
engine power necessary to drive large
vessel through the water at high speed
was matter entirely exterior to the YES
sci itself. In brief. he discovered that the
question was one of determining the
measure of propulsive energy lost through
wave-making and the overcoming Of frtc-
ton between the water and That part OF
the vessel which came below the sur
face OF the sea.
1t Is hardly necessary to go into the
exact terms Of the Froudian law Of the
ratio OF speed to shape. the method Of
determining the best possible build for
a vessel in order to attain the highest
possible speed Is the ultimate aim of the
testing basin" The mathematical meth
Cd OF attainment of this end are too in
tricate to be interesting to the layman |
Suffice it to say that there is a definite. |
known ratio between shape and speed. |
The method OF procedure in designins |
a warship of any class-be IL dread !
nought. gunboat. torpedo destroyer orr
dispatch boat-is usually along the fol-
lowing lines.
Specifications Drawn Tn.
Upon the appropriation by Congress- Of |
the necessary funds to build the vessel
the board Of naval designers at the NAVY
Department Immediately sets to work To