The Pensacola journal. (Pensacola, Fla.) 1898-1985, 1915-11-29
NEW BAT TLESHIPS
Be OVER 300 FEET
IN LENGH OVERALL
BE TWICE AS LARGE AS ANY
VESSEL PARTICIPATING IN
SPANISH AMERICAN WAR AND
500 FEET LONGER THAN ANY
BATTLESHIP AFLOAT.
BY ASSOCIATED PRESS.


Washington, Nov. 28.-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 American
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
80 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 pro-
pellers, to attain that pace and the
hull designs of the models show a
huge, square cross section amidships
in order to accommodate the mass Of
machinery.
There is no longer any doubt about
the amount of horsepower required to
drive ship of known design at any
desired speed. The model basin has
done away with speculation on that
point. 1t is huge tank several hum
dred feet long and thirty feet wide,
above which runs a travelling bridge
arrangement carrying the compli-
Gated mechanism to measure the re-
sistance offered by a model hull
towed through the water. The aver
age battleship model is twenty feet
long and is in exact proportion to
the ship it is planned to construct.
1t has been established as a law of
physics that the power required to
pull a model through the water at
six knots, for instance, will show ex-
actly the force necessary to drive the
ship herself at a 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 So knots an hour and
which will carry heavy guns and no
armors whatever. She will be new
type Of scout cruiser rather than a
battlecraft, it is understood, and have
less endurance than battle cruisers.
The navy model basin is now
equipped with wave-making device
with which the rolling qualities of a
ship design can be tested and also her
ability to sustain high speed in rough
water. 1t consists of a motor driven
fan under water which stirs the con-
tents of the tank into wave motions
of any desired frequency or size. Al
the opposite end of the tank is 3
beach over which the waves run TIC
be trapped in the space behind, pre-
venting their return up the tank te
interfere with experiments. More &C.
curate data on ship construction has
| been given out from the navy plant
| than from all other similar tanks il
4 the world combined. 1t <has a ca
/ pacity of testing $50 or more models
annually as compared to SO in the
British admiralty tank. Nearly 200(
models have been tested at the navy
yard and the results carefully tabu
lated. In slack periods regular Sc
ries of test models is produced anc
the results noted in order that the
whole scientific field may be covered
The officer in charge presents tn,
new data gathered before a scientifi,
society each year and private design
ers can now work out the hull of
merchant ship on the formulas gath
cred by the government. About
] fifth of the work now done in TIN
basin is for private shipbuilders VIII,
send plans of proposed ships to tn
navy yard where models are con
structed and tested. The plant sool
will have a capacity of producing an,
testing one model every twenty-fou
hours.