Free trader-journal. (Ottawa, Ill.) 1916-1920, 1918-06-05
U.BOAT MENACE
IS DWINDL|NG
Listening Devices, Depth Bombs
and Destroyer Fleet Beating
Submarines.
CONVOY SYSTEM Efficient
Wrecks of Tirpitz' Tefrors Sire" BOT
tom Of English Channel and North
Sea Mine S~eepers do Good
Work.

I.Ondon.-The menace uf the Ger
man submarines and mines Ia thu
maritime commerce of The allies Is he
coming less week by week The I'm
proyemeat is due chiefly Ia The deNel
opment of the listening devices ami the
depth bombs carried On the sWifi-moN
ing destroyers. The hydrophone Is the
most useful invention that has been
discovered by the navy In its ahllSuh
marine crusade, and il is being I'M
proved upon all the time.
When u-boat is spotted from aloft
By one of the alert observers In The
seaplanes which wing their flight Otei
the North sea and the waters around
the British Isles. he signals the posi-
tion to the nearest destroyer. Direct
" he gets this information her com
mander steams AT full speed In the di-
rectlon indicated until he can hear the
submarine plugging along under water.
The destroyer follows the U-b0at for
hours, il necessary. until the com
mander thinks he has got the enemy In
the right position for hit, and then
lets 90 the bomb
Loss Keeps Pace With Construction.
While the number of enemy under
sea craft that are sunk or captured
each month is not given out for publ
cation II is known that II equals the
construction of submarines In Ger
many. The greatest blow To German
hopes of destroying the commerce OF
the allies on the ocean lies in the con
v0y system, which Is rapidly approach
Ing perfection. When the plan Of es-
corting transports and supply ships
right across the Atlantic In large fleets
was first tried out there was consd-
cradle delay on account Of difference
In speed of the various ships of which
IL was composed
At the present time conveys are all
classified according to speed, and II
fast transport can make round trip
In 30 days. while the slower class OF
supply ships drift across the ocean at
steady six or seven-knot gait.
The number of British and American
destroyers has increased rapidly and
Is still growing 50 that there are plenty
OF these essential watchdogs Of the sea
to make the passage Of conveys across
the Atlantic aud North sen secure. The
greatest percentage Of losses by sub
marines since January has been In
ing reduced by increasing the number
Of drstroyprs In those waters. No sub
marine commander will risk attack on
q convoy which Is protected on all four
sides by destroyers and frequently ac-
c0mpanied by seaplanes.
Naval experts are confident that
when there are sufficient destroyers to
escort all conveys required to trans
port troops and munitions from Amer
len to England and France the subma-
fine peril will be practi, ally ut an end
This stage should be reached by Au.
gust. AT the present time the U-bOatS
watch and walt for vessels which ARE
alone
The sinking Of vessels In the Irish
sea has been due to the tact that the
water there is muddy aud not too deep
nnd II submarine can lie on the bottom
and come up at night. Quite recently
In two instances, when steamships
We're torpedoed In the Irish sea de
stroyers blew one U-boat to pieces viii
Il denth charge and damaged the Othe
one so seriously before she could sub
merge that the commander surren
dered with hts crew.
Pilots OF seaplunes and airplane
who fly over the waters around tn
British Isles have reported numbers .
submarines which We're sunk month
ago and are lying on the bottom Of tn
channel ana North sea.
Traps a Peril to U.boats.
In addition to destrOyers and patro
boats which scour the surface IN ever
direction, there are all kinds Of trap
and obstacles placed under waite
which make the passage Of Dove
straits and exit from Heiigoland high
a very complicated problem for
V-boat commander to solve. Hundred
Of mine sweepers, manned by fisher
q H..
service. are at work day aud nigh
making the ocean lanes safe for steam
ships belonging 70 the allies and npu
trial nations, Their crews have becom
adopts Ia the ART of finding aud eS
ploding German mines hidden heo,
the surface.
During The year ending In April NOR
than 1000 mines which cost 81 .00
each to construct. were exploded &
captured by the British mine sweeper
The loss of mine sweepers was yer
small IN comparison. In one lnstant
u mine sweeper found German min
drifting In the North sea. and towed
over we'll IN toward the mouth of I'm
under cover Of fog. After pumping
up the crew sei the mine ~ feet hplo
the surface, and II hours later II WI
struck by German steamship boun
for Gothenberg from Bremen, aud III
vessel and her cargo Of Iron ore wei
to the bottom.
The increasing hazard against sui
marines eyer returning Ia port Is nal
Ing II difficult for the German adml
atty to gel crews to man them.