New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1917-07-07
Anti-Submarine Campaign
Fails to Keep Pace with
German Inventions
Pumps Hold Craft
Motionless in Water
Telescope Periscopes and
New Fuel Lessen Dan
ger of Detection
fFrcrn The Trtbune Buresul

(Frcnn The Tribune Buresul
Washington, July 6.-Four important
improvements are known to have been
adopted By German submarines since
April 1, but the progress made by this
country and its allies in perfecting
devices for the destruction Of U-boats
is declared to have been almost negli-
BILE in that time. The four known de-
velopments since April are:
1. Four small pumps, regulated by
electrical devices. enable the submarine
to remain motionless under the water.
Formerly the submarine was obliged TO
come to the surface, like a whale; it
planed up, assumed level position on
the surface, and to submerge it planed
down for the dive, the operation re-
quiring two and one-half minutes. 1t
was obliged, also, to continue in mo-
ton always, unless anchored 70 the
bottom, being in this respect like an
airplane, which has to keep going or
fall to the earth. The submarine, be-
fore the new device was installed. would
either sink or rise to the surface If it
stopped.
With the pumps. II the tendency is
to rise when the U-bost is motionless,
more water is dumped ins if the ten
dency is TO sink, water is pumped out.
Thus the submarine is now enabled 10
visit any spot in the ocean, submerge
to the desired depth and lie perfectly
still.
Less Fuel Consumed
Before this device was installed the
throb of the submarines propellers
was heard by submarine chasers. Now
the submarine may elude the pursuer
by standing still under water. Former
~ the submarine used up the power IN
its storage batteries, and that meant
fuel consumption in some form. NOW
by being able to stand still, it con-
sumes less fuel and is enabled to stay al
! it's post for a considerably longer Time
than formerly.
2. Submarines are using telescope
periscopes. The U-boat floats very near
TO the surface, then suddenly shoots up
b lLS III liio HihiiiNt DNthb -
abled 10 detect as quickly as being de-
tected. The telescope IN the same man
ner may be withdrawn instantly, and
the submarine can change its position
without leaving a wake. Heretofore,
the periscope went slashing through
the water, leaving a great white wake
8. Now the submarines Diesel en-
gines are supplied with oxygen and q
90, tphfrh faka
the place Of air. The exhaust is broken
up by series of widespread, hne-
meshed nets, SO that the gas is washed
free of smoke, and when the gas comes
TO the surface it is in infinitesimally
small bubbles, which do not make any
wake.
4. Remarkable improvement has been
made in the submarines telephone and
listening devices, enabling it to hear
and 10 locate at a considerable distance
the direction and the type of vessels
from the frequency Of their propeller
returns. This listening radius is usual
ly about FIVE miles.
Allied Problem Increases
These and other probable improve
ments in the submarine as employed by
Germany are increasing the difficulty OF
the American and Allied problem IN
protecting merchant ships and main
tanning the lines of communication
overseas. Despite various stories which
have been published alleging the dis
coyery Of effective anti-submarine de-
vices. il was asserted by an authority
to-day that no real progress had been
made, and that the Navy Department
has. quite on the contrary, settled on
definite policy for fighting the subma-
rines. comprising two features which
have been known for months, bit which
il was popularity supposed were being
augmented and elaborated by new de-
vices.
The policy was said TO be the employ
ment of. first, the naval type of ves-
sells. and, second, the 110-foos subma-
rine chasers. A related part Of the
policy was said 10 be the construction
Of every merchant ship possible to Of
set the expected destruction OF bot
toms by German submarines.
Some naval critics asserted to-day
that the true solution lies in protec-
tion of merchant craft, rather than the
construction of new bottoms, holding
that the building Of fighting ships is
more essential than immediate con-
struction of other vessels, as the ne
cessity is to bend every energy toward
the destruction Of submarines. The
criticism was based on the dictum that
il is easier to preserve existing tom
mage than to construct new and fur
ther advantage was said to be that the
country, at the end Of a given period,
would have not only the tonnage de-
stroved but also that which is new, in
addition to the newly built fighting
craft with which 70 protect all of il.