The Scranton tribune. [volume] (Scranton, Pa.) 1891-1910, 1897-05-22
Three Recent Additions
To Uncle Sanm's Navy.
The First of Our Light Draft Gunboats
Intended for Duty i'm the Far East.

The fine performance of the "Wil-
mington" and Helena" on their recent
trial trips has occasloned an added in
terest In the forthcoming test Of the
Nashville" which will take place in
a few days, These vessels were pro-
vided for by act of congress approved
March Srd 1893, and in January of the
year following their building was
warded to the Newport News Ship
building company of Newport News,
Va, SO thoroughly have the builders
carried out their contract that, not
only have the vessels won the highest
praise for workmanship, finish, and
performance, but their excess develop
ment of speed has already netted the
contractors the snug bonus of $9l, ,452,
while the premium on the Nashville"
has yet to be heard from. This re-
ward is the only proper compensation
for the low figure, $2S00O0, for which
each vessel was built. Three years ago
the Newport News company was an
untried factor in naval shipbuilding,
but to-day the yard is firmly estab-
lished upon an enviable record of
faithful performance and skillful work
The Nashville is 220 feet long on
dHe WdlSI-llHt, OdS u nldNl1nuIn Detlnn
OF 3S feet inches, and draws II feet
of water on a normal displacement of
1,31 tons. When ready for sea, under
the usual cruising condition, she will
carry about $50 tons OF coal; but her
bunkers have a total capacity Of 399
tons, and that will be her supply when
loaded for a long trip. With this latter
supply, she should be able to cover a
ic4o 4
a cruising speed of eight knots an hour
an exceedingly active radius for
craft of her size.
HOW RIGGED.
The Nashville is rugged as a two
masted schooner, and will carry just
sail enough to steady her in a seaway
Like the other boats, she is built of
steel; and in model is rightly consider
ed a prettily formed craft. She is de-
signed for a speed of IA knots; but it is
needless to say she will reach 16 on
her trial. To attain this end, the YES
sci has had her engines designed with
especial consideration for economical
efficiency under both cruising and full
speed conditions; and even the layman
may in part appreciate the cunning
shown in their get-up.
Her motive power consists of two
sets of quadruple expansion engines
driving twin screws, and it is of inter
est to know that she is the only craft
in our service, other than torpedo
boats, carrying machinery of this sort
For the sake of economy, the low
pressure cylinders are arranged to dis
connect leaving the three other cylin-
derS to do the work at cruising speeds;
but at full speed all four of the cylin-
ders will be pushed to their utmost
Without going into the technique of
the arrangement, one must know that
an engine usually develops it's maxi
mum efficiency when running at it's
highest speed; and by using these en-
gines at their maximum either as tri-
pie or quadruple expansion engines, in
stead of running with one cylinder
limping, so as to speak, the result is
economical performance.
TWO KINDS OF BOILERS.
To attain this end upon a reasonable
expenditure of coal, the boat is fitted
with two kinds of boilers; one kind de-
Veloping steam at a working pressure
of l6O pounds, and the other sort gen.
Grating steam at a pressure of $50
pOuIblS. OIAeI cruising conditions, the
two 160-pound boilers will meet the
needs of the engines run in their triple
expansion form; and the four other
boilers will be called into reuuisition
only when the vessel is making her
maximum speed and using her full
power. Then, the four high powered
boilers will seem to exist only for the
initial supply of the two high pressure
cylinders, which will exhaust their
steam at a pressure equal to that of
the full head from the two 100 pound
boilers. Buch such is not the fact, for
that exhaust will commingle with the
fresh steam of 100 pounds and, togeth-
er, supply the added tax upon the
other cylinders. This is only a part of
the careful balance of power and nice
adjustment present in the Nash
ville's" machinery; and their perform
ance is sure to result in congratula-
tions for their designers as we'll as for
their builders.