Evening star., 1931-12-06
u. S. Designs Superliners to Compete
With Foreign Ships for Ocean Trade

with the effort to keep down weight
and attain high speed
With an existing efficiency of about
SO per cent it was found that pre-
heaters would increase this by but little
over 3 per cent, while at the same time
$500 square feet of crews quarters
would be lost and the number of burn
ers boiler increased by 40 per cent.
Estimates made indicate that a
greater return on the capital invest
ment will be obtained by adopting a
simpler and light boiler plant than by
having heavier and more complex
piant even though there might be a
slightly higher thermal efficiency.
Like few of the newer vessels built
In foreign countries in recent wears
these new liners will contain much
high-elastic steel, making for light
weight coupled with increased strength.
In the United States no such steels
nave been available In the mast because
the size OF ships built did not require IT.
Took Years Research.
The consequent absence Of American
companies capable Of building the re-
quired steel led to an extensive re-
search over year. Finally after con-
sultation with other steel manufac-
turers the Jukens Steel Co. agreed In
develop for shipbuilding purposes a
nickel steel similar to that us.d IN
locomotive boilers. The distinct advan-
tage OF this steel Is that its high elastic
properties are attained without the
usual heat treatment Il thus becomes
possible TO heat the steel for welding
purposes without losing this important
Characteristic.
To further reduce weight. especia,,v
IN the higher parts of the ship, much
Oh the housings above the sun deck
VIII be made Of aluminium alloys This
Is expected to save more than 200 tons
top weight ''
Frequent transatlantic voyaeers viu
be pleased to learn that the snnovino
vibrations present In many of the hest
and quickest liners Of the existing ara
VIII oe materially reduced by addi-
tlonai strengthening of all parts Un-
certainty as to definite accomplish
ments and the injection of additional
weight and the incidental loss of space
led to the rejection Of any form of
mechanical stabilizing device. Expert
euce mas shown that where anti-rolline
tanks have been installed on other
snlps their use has been abandoned.
Sea Plane Mail Factor.
Since the funds derived from carry
ing the mails form q substantial part
OF the revenue of any high-speed liner,
lt becomes necessary to give considera-
tion regarding sea plane mail delivery
from the ship while at sea. Adequate
catapults for launching the planes
ana cranes for hosting the mail planes
aboard will be provided
Iaking lesson learned during the
World War, when German armed mer-
chantmen terrorized shipping on the
seven seas, consideration has been
given to the potential use of sucn
superliners during times of hostilities.
naval treaties between the United
States and foreign powers have brought
ABOUT new and distinct relationships
between naval vessels and high-speed
merchant ships. Such treaties limit
the standard displacement OF naval
cruisers to 10000 tons.
Such limita ton on disarmament
put definite, practical limit on cruiser
speeds, for it limits the weight of ths
ship, and after reasonable allowances
is made for protective armor the re-
mainder Is available for driving mech
anism of limited power. Thus ths
practical speed of present cruisers. in
cluding the much publicized German
pocket battleship," is but 80 or "a
knots, quite in the speed class of pres
ent merchantmen.
Convert to Auxiliary Cruiser.
Developments in the art of shin
building now make it possible TO con-
vert high-speed merchant ships into
powerful auxiliary war vessels, while AZ
the same time they can carry enough
passengers In times OF peace to MAKE
them economically useful This condi-
ton has not existed In the past.