Tensas gazette., 1912-04-05


service today. the loss Of life Incl
dent TO the development of these ves-
sells is perhaps not so great. but the
circumstances surrounding death In
a submarine are such as to make a
deep impression.
Much has been done to make the
submarine safer than 1t was Is years
ago. but the ingenuity of man may
never succeed In making these boat
a. reasonably secure from sudden de-
struction as other vessels. The near
est approach to a submarine in
strength of hull is the battleship. and
the very size of the battleship makes
1t possible to minimize the conse-
Quences of damage by subdivision Of
the ships interior. especially the
space LYING between the outer and
the inner skins. In submarine, how
ever, an outer and an inner bottom,
with intervening air space, would i'm
pose conditions which would seriously
cripple the efficiency of the craft. In
effect there are double hulls in boats
OF this description, but the steel skins
form the bounding walls of ballast
tanks into which water Is admitted to
increase the dead weight of the yes
sells and to cause them to lose just so
much buoyancy. To be sure when run
ming in surface trim the ballast tanks
are factor Of safety, and II damaged
In that condition the submarine is as
well on as any ordinary craft of sim
liar seaworthiness. Unfortunately all
the accidents that have happened to
submarines have occurred when these
boats were either running submerged
or were being trimmed, that Is. taking
water ballast aboard for under water
work or when they were deficient in
reserve buoyancy.
Like corked Bottle.
Take bottle and put some shot into
1t, just enough to make it float up
right, and then cork 1t. It will never
sink unless 1t is punctured SO that en-
tering water can expel the buoyant
air. II you made a small hole in the
under side Of the bottle, the flask
would sink deeper, but It would not
90 to the bottom 1t would be more
sluggish In response to surface dis
turbances. in fact seem less disposed
than ever to capsize.
/ Suppose now on the other hand that
you loosen the cork so that air NAV
escape then the flask win all ouick-
ly and 1t will be only a short while he
fore the bottle disappears. In gem
eral way this is parallel to the func-
ton Of filing the ballast tanks Of
a submarine. water taking the part
there Of shot in the bottle, and the
puncture being q duplicate of the
valves which q submarine opens 10
allow water to pass similarly upward
into the ballast tanks. But not epoueb
water from the sea would enter the
tanks II air were not permitted to ea-
cape from them. and SO vents are open-
ed in the tops of the tanks. and the
expelled air generally mingles with
that In the free space inside of the
vessel OF course, this produces
slight atmospheric pressure. but II IA
not Objectionable.
SO far the submarine is Ike The
corked bottle. all Of her hatches be-
ing sealed. Now in order to bring the
under water boat down deeper in the
water, 80 as to make her Responsive
to her diving rudders when she "a IN
nation. more water is admitted To :
special tank, and the cork Of This
tank is drawn. the air escapinx. bpt
the matches still remain tight Al
result the little craft has still a bpov.
ant margin which holds her at the ,,,r
face; two or three hundred pounds asd-
ed weight would make her sink ana !,
is the commanding officers particular
care to see that leakage does not d.
stroy this reserve.
How They Dive.
The diving rudders compel thu cr,f,
to go under water against an imnul.s
Of only few hundred pounds OF buor.
ancy, and this buoyancy is always az.
erting lifting force to bring the YES.
eel to the surface when the enein.
stops. To increase the measure Of
this safety factor would mean that the
diving ruddefs would have to be set
at greater angle to drive the boat
downward and to keep her under the
surface, and more Of the power Of the
engines would be absorbed In this
work. reducing the speed forward
One gallon Of sea water weighs
about eight and one-half pounds. and
the admission OF rs gallons would sub
sequently destroy the working reserve
OF buoyancy Of most Submarines. Ii
would not take much of hole to let
In that quantity Of water In q few
moments II overrun and pierced BY
a surface craft the submarine would
be sent TO the bottom like the loaded.
perforated uncorked bottle. This is
just what happened the other day to
the AS This brief outline Of the gem
eral principle upon which an under
water boat is made ready to submerge
and Ia controlled below the surface
makes It easy to understand some Of
the accidents that have happened to
submarines.
Tno American navy has been fortn-
nate 80 far in its experience with
submarine boats. although there has
been more than one narrow escape