Evening star. [volume] (Washington, D.C.) 1854-1972, 1929-09-22
BRITISH MAY PLAY
SUB AS TRUMP CARD
Crafts Usefulness Reported
Hurt by Mechanical Ears.
Light Cruiser Favored.
BY HAROLD E. sCARsBoRoUGH.

BY HAROLD e. SCARSBOROUGH.
BY Radio to The Star.
LONDON, September 21.-In naval
circles here there is some speculation
as to whether, at the proposed five
power naval conference, Britain will
play what naval experts regard as her
trump card-in other words, whether
it will be announced publicly that the
development of anti-submarine protec-
ton by the British navy has been so
far advanced that Britain does not care
whether other nations construct sub
marines or not, but favors their aboli-
ton on purely humanitarian grounds.
When, at last years naval confer
ence, the terms of the so-called Anglo
French compromise" became public, 1t
was found that the Conservative gov
eminent had no objection to the un-
limited construction Of small subma-
rines by France. 1t is now possible to
reveal that even at that time the naval
PSpeyts Ss-e confident that the pos
session of large feet of such war
craft by near neighbor constituted no
serious menace to the countrys ship
ping.
Surface Craft Favored.
It Is still admitted that big, ocean,
going submarines might manage to play
havoc with British ships in the same
way that the German warship Emden
did during the World War as surface
craft. Hence the admiralty's insistence
upon number of small cruisers. But
in marrow seas" the admiralty has
informed the cabinet, submarines can
ace. This assurance has been given as
the result of experiments carried out
over q period of several years from the
submarine base at Portland on the
Channel coast, where the navy's anti
submarine school is located.
The admiralty places its confidence
In being able to deal with undersea
war craft chiefly on what is termed an
almost uncanny perfection of the lis
tening apparatus its experts have
evolved. It is asserted by British naval
technicians that the service has Gre
ated microphoneS, or Sound-ranging APP
paratus. which is so highly sensitive
that submarines can be detected not
only when cruising but that 1t can be
determined with some certainty wheth-
er submerged bodies are metallic OBJ
jects or merely rocks.
These microphones, details OF which
. naturally are closely guarded, are.
nevertheless, said to be strongly con-
structed and quite capable of produc-
ing satisfactory results, even when not
installed or operated by experts. They
can be fitted to any type of ship.
How Ears" Function.
The mechanics of the methods, which
have been evolved at the Portland base,
are as follows:
When a submarine. with propellers
running. comes within range Of the
listening sets, her position and course
are checked by cross bearings, and then
it Is left for destroyers or hydroplanes
to attack with depth bombs. The
British also have constructed mortars
with which depth charges can be drop
ped by slow moving vessels Sufnc1ently
far enough away from themselves to
avoid danger from the ensuing explo-
sion. Detection of motionless undersea
craft, it Is said, Is carried out by
echoes. That is, when 1t is suspected
that a submarine is in the vicinity pa
trolling vessels sound submarine" bells
or produce other underwater sound
waves; and Judge by echoes received
whether the sound waves are being re-
turned by rocks or by the metal hull OF
a submarine. It is further claimed
that both methods of detection have
been so far developed that submarines
can be located before they get within
torpedo range.
The Portland base schools also are
said to have improved the old wartime
precautions such as defensive nets and
to have perfected explosive paravanes,
which can be fired either by contact or
electrically.