Ottumwa tri-weekly courier. [volume] (Ottumwa, Iowa) 1903-1916, 1915-12-04
TESTING NEW wARsHlPs.

Some idea of the size and power OF
the super battle cruisers proposed as
part Of the new naval program may
be gained from the fact that each one
would be 800 feet long-more than
twice as long as any battleship which
participated in the Spanish-Amerlca
war, more than 200 feet longer than
any battleship now afloat and ten feet
longer than was the Lusitania.
Tests Of hull models for the giant
cruisers are proceeding at the model
basin in the Washington navy yard
to determine just how much horse
power will be required to drive them
thirty-five knots an hour, the speed
fixed by the navy general board. 1t
will take six separate sets OF steam
turbines, it is understood operating
six propellers to attain that pace and
the hull designs of the models show
a huge, square cross section amid
ships in order to accommodate the
mass Of machinery.
There is no longer any doubt about
the amount of horse power required
to drive q ship of known design at any
desired speed. The model basin has
done away with speculation on that
point. It is huge tank several hun
dred feet long and thirty feet wide,
above which runs travelling bridge
Arrangement carrying the complicated
mechanism to measure the resistance
offered by model hull towed through
the water. The average battleship
model is twenty feet long and is in
exact proportion to the ship it is plan
ned to construct. 1t has been estab-
lished as law of physics that the
power required to pull model
through. the water at six knots, for
instance, will show exactly the force
necessary to drive the ship herself at
predetermined rate. The effect of
any minor change in hull construction
is instantly shown by the recording
instruments. An eighteen knot speed
can be reached in the tank.
Indefinite information has reached
navy officers that England is building
a swift vessel as an experiment which
may reach thirty-fve knots an hour
and which will carry heavy guns and
no armor whatever. She will be q
new type of scout cruiser rather than
. battlecraft, 1t is understood, and
have less endurance than battle
scruisers.
j lao navy IAOuC1 UCloAA 40 INV SANAP
ped with wave-making device with
which the rolling qualities OF ship
design can be tested and also her
ability to sustain high speed in rough
water. 1t consists of motor driven
fan under water which stirs the con-
tents of the tank into wave motions
OF any desired frequency or size.
At the opposite end Of the tank is a
beach over which the waves run to be
trapped in the space behind, prevent
ing their return up the tank to inter
Herewith experiments. More accurate
data on ship construction has been
given out from the navy plant than
from all other similar tanks in the
world combined. 1t has a capacity
OF testing $50 or more models annually
as compared to fifty in the British
admiralty tank. Nearly 1000 models
have been tested at the navy yard and
the results carefully tabulated. In
slack periods regular series of test
models is produced and the results
noted in order that the whole scientif-
ic field may be covered. The officer
In charge presents the new data gath
cred before scientific society each
year and private designers can now
work out the hull of a merchant ship
on the formulas gathered by the gov
eminent. About a fifth of the work
now done in the basin is for private
shipbuilders who send plans of pro-
posed ships to the navy yard where
models are constructed and tested.
The plant soon will have capacity of
producing and testing one model every
twenty-four hours.