Evening star., 1939-05-28

bottle is broken. allowing the oxygen to
escape into the gas chamber. At the bot
tom Of the apparatus, which is strapped
around the users chest, are two strips
OF fabric, on rollers. They resemble
small window shades. BY extending these
two cloth planes on either side of him,
the user is able to retard his progress
upward through the water and thus
avoid that nightmare of deep-sea divers,
the bends" which result from a too
rapid rise through planes of decreasing
water pressure. Five men escaped from
the British submarine Poisiden in 1882
by using this invention.
A comparison of the British and Amer
lean devices may serve to illustrate why
the Momsen Hobson lung" is considered
superior to any other. Instead of pro-
viding each lung" with its individual
oxygen bottle, as do the British, Ameri-
can submarines carry one large, common
supply tank of oxygen from which a
''lung" may be filled in a few seconds,
just before 1t is to be used
When individual oxygen bottles are
used, American experts point out there
is always a danger that during periods
when the lung" Is in storage the oxygen
will leak out and the user of the lung"
in moment of emergency, may find
the supply exhausted. The common sup
ply Of oxygen on American submarines
is checked methodically - there being
only one thing to check-and a supply
is thus constantly assured.
American Lung" Lighter.
The American lung" too, is much
lighter than the British, weighing only
pounds, in comparison with or 10.
On submarines every ounce of excess
weight counts. Due to its heavier weight,
only one Of the British lungs is issued
for each man aboard a submarine.
American undersea boats carry two for
each man .(giving him a spare in case
one should be defective), and, in addi-
ton, surplus of 10 per cent OF the
total issued to personnel.
The German version of the lung"
like the British, carries an individual
oxygen bottle. American experts believe
that foreign designers. in adding this
cache of oxygen and thus making their
apparatus heavier and more cumber-
some, were inclined to overestimate the
amount of oxygen required to breath
even during a SLOW rise of several hun
dred feet from the sea bottom.
One American authority on submarine
safety devices pointed out that a man
rising from a submarine 165 feet below
the surface starts up with approximately
five times the amount of air in his sys-
tenn he would have at sea level. II he
husbands this supply, breathing slowly
and easily, very little additional oxygen
is needed.
The nations named-Italy, Germany
and Great Britain-are, so far as is
known here. the only ones who have
done any original. successful research
work on submarine safety devices
When the United States Navy author
lied the sale of the Momsen- Hobson
lung to foreign powers, the opportunity
to purchase it was quickly seized by Nor
way, Spain, Argentina and Brazil.
Japan = Mystery.
What Japan has done is something OF
a mystery. A Japanese representative
several years ago bought two of the
American lungs from the Mines Safety
Device Co., which holds the exclusive
right to manufacture them here. About
six months later the japanese purchased
six more. Obviously, eight of the de-
vices were not enough for the entire
Japanese submarine service, so it is as
sumed that the Nipponese bought them
with the idea of copying them in their
own factories.
Japan these days surrounds every
thing naval with thick cloak of secrecy
even safety devices. Consequently, the
Navy Department has not been informed
as to what the japanese are doing with
this American invention or about any
other contribution they may have made
to the safety Of submarine operations.
The French, it is understood use the
British-type lung" or some close ap-
Proclamation OF it. So far as is known
here, they have made no original con-
tribution to submarine safety.
Although the United States Navy,
through the lung" the escape cham
ber,' the "eye" for raising submarines by
means of chains and other innovations,
leads the world in making the risky sub
marine service bit less risky, it is not
resting on its laurels. 1t. Comdr. Nom
sen, Comdr. McCann, Mr. Hobson and
| others constantly are engaged in re-
search work to perfect further their
original apparatus.
Use Of Helium Vital.
One of the more recent improvements
is the mixing Of helium with the oxygen
breathed by divers. This mixture en-
ables them to descend to a much greater
depth than was formerly possible. Until
recently it was believed that 800 feet
was about the maximum depth at which
divers could safely work. Using oxygen
alone, that was true. Since a diver is
required to attach a rescue chambers
down-haul cable to submarine, the
chambers use is limited to the divers
field of action.
However, in late tests with the helium-
oxygen mixture, successful diving opera
tions have been carried out at a depth
of 500 feet. Helium, being extremely
light, increases the facility of breathing
under tremendous pressures.
So, imbued with the spirit of true
scientists, the Nays submarine men
are not content with todays achieve
ments, but constantly look forward to
the time when the operation Of under