The Bismarck tribune., 1931-04-08
BY ADMIRAL HUGH RODMAN
Written for NEA Service


Written for NEA Service
Washington. April Sit is difficult
to describe definitely the character
istics of the polar ice fields. but this
very uncertainty regarding them rep
resents the chief danger which
threatens the success of the Wilkins
submarine expedition across the
Arctic.
For although reliable explorers like
Peary, Nansen and Amundsen have
obtained great amount of informa-
ton, at specific times and places. they
all record that the ice is almost al
ways in state of motion due to cur
rents, tides and the terrific storms
which are prevalent.
Take the matter of thickness, q
most important consideration for the
Nautilus, since her maximum diving
depth is about 200 feet. Ice while
floating will be about one-eighth
above and seven-eighths below the
surface of sea water, and where Arctic
ice has been undisturbed it probably
will average only about eight feet
in thickness.
On the other hand, where there has
been open water, and the fields have
been driven together, they are Tapped
and overlapped into hummocks and
pressure ridges" which often reach
30 feet in heighth. In such a case,
following the flotation rule, 1t might
extend 200 feet below the surface.
Reports have been made Of measure
ments showing the ice. even in fairly
. level fields, to be from so to 100 feet
! thick.
Rough Going on Bottom
But in general, the upper surface
of the ice fields Is extremely rough.
due to ages of buffeting and grinding
and extreme pressure. It seems per-
fectly reasonable to assume that the
underside of the ice is corresponding
" uneven, and that it indeed will be
rough shedding when the submarine
attempts to glide along its bottom
side.
Leads are fractures in the fields
where open water appears, but these
may not occur for days at a time.
Hence I cannot imagine how the
Nautilus can depend on either finding
or regularly utilizing these leads.
To those on the surface, the pres
ence and location of leads are lndl-
Gated by a dark reflection in the sky.
But the Nautilus will be going It
blind and can only detect them BY
looking through a glass deck plate.
If conditions were favorable, she
might bore through the ice and use
her coming tower to locate such re-
Elections.
Might BE Caught
Even should she detect leads, and
find her way to the surface, they
might prove more of menace than
a blessing. For even with ships de-
signed especially to Withstand excess
sive pressure, disaster Is not infre-
quent when leads close about them,
and any pressure which might start
a leak by opening the seams Of the
Nautilus would probably result in the
loss of much Of her fuel oil.
There is still another feature which
has been brought home to me by ac-
tual experience in the ice-that q sub
marine, even while running on the
surface, is about the poorest type pos
sible for cruising in ice-infested areas.
A wooden vessel with a single SLOW
revolving propeller is far less liable
to injury than one with small, rapidly
revolving twin screws.
Ten years ago when in command
of the Pacific fleet, attempted to
enter Yakutat Bay. Alaska, with sew
eral destroyers. Though the Ice was
very loose, and there was much open
water, we found 1t hazardous to pro-
ceed and promptly withdrew. Even
then. one Of the propellers was bent
Rudders Are Exposed
In addition to this sort Of handicap
q submarine has horizontal rudders
or planes that are used In diving
They also are in an exposed position
near the propellers and are liable te
damage or arrangement. Whether
or not ice. may form on these out
board fittings, and cripple. them, L
another thing to be considered; u
say nothing Of Ice that may form Or
the hull itself.
Should the batteries become ex.
hausted and the submarine attempt
to rest against the under surface o.
the Ice, I believe she viii have trouble
staying. in one position. The Arctic
Is q placc-bt storms, often Of hurr1-