Evening star., 1946-03-26
Undersea Atom Blast
Planned TO Replace
Surface Explosion
BY the Associated Press

A plan to increase the ship
crushing effect of the second
atomic bomb test is under
study. 1t calls for exploding the
weapon under water, rather than
on the surface.
Saying the change probably will
be adopted. experts familiar with
the work of the joint Army Navy
bomb test task force told a reporter
it would not, however, supplant the
projected third eXperiment-an ex-
plosion several thousand feet below
the surface of the sea.
But they said the detonation in
the comparatively shallow water of
Bikini lagoon would simulate more
closely an operation against a fleet
at anchor than the previously con-
sidered ideas of exploding the bomb
at or slightly above the surface.
Would Represent Depth Charge.
A bomb set off at depth of 25 to
so feet would represent a delayed
action mine planted by stealthy
submarine or superdepth charge
dropped by an airplane. The Bikini
lagoon is some 180 fsee deep in spots,
To carry out the plan, it is as
sumed the bomb would be sus-
pended by cables below a barge or
landing craft and exploded by a
time fuse. Task force officials.
struggling to arrange the second
test as near as possible to the
time of the first explosion, said they
believed the underwater plan would
entail no delay
The first test, now set for early
July, is to be an explosion several
hundred feet above the target fleet.
The bomb is to be dropped by a
high-flying B-29.
No Special Casing Needed.
1t was explained that at the rela-
lively shallow depth contemplated
for the projected second blast no
special pressure-resisting casing
would be needed. This is one of
the reasons for the already an
nounced long delay between the
second and third tests.
BY exploding the bomb even
slightly under water, the mechan-
ical effects of the explosion are ex-
pected to be aggravated in consid-
able degree. The amount of hull
crushing shock transmitted through
the water may be substantially
greater than that produced by
lateral blast such as would result
from an explosion at the surface.
The membership of both groups
of judges for the test was expected
to be completed today. President
truman late yesterday announced
his appolntees to nine-man civil
ian commission to evaluate results
OF the tests for the White House
and the public. This cleared the way
for announcement by the task force
OF SeVen-man, military civilian
board to make military evaluation.
Truman Names Commission.
Mr.. Truman assigned four mem
bers of Congress to his commission
Senators Hatch. Democrat, of New
Mexico, and Saltonstall, Republican,
of Massachusetts,; Chairman May of
the House Military Affairs Commit
tee and Representative Andrews,
of New York. Senator
Saltonstall Is a member of the SEN
ate Naval Affairs Committee, SEN
ator Hatch of the Foreign Relations
Committee and Mr.. Andrews of the
House Military Affairs Committee.
Serving with the legislators will be
DR.. j. Robert Oppenheimer, one of
the pioneers in atom bomb design;
DR.. Karl Compton, president of the
Massachusetts, Institute of Technol-
ogy; Bradley Dewey, the former
rubber administrator; William S.
Newell, Bath CMe) Iron Works pres
ident. and Fred Searls, jr., mining
engineer and special assistant toI
Secretary of State Byrnes
The Presidents choice of two
Senators and two House members
won general approval in Congress.
Senator Mcmahon said he was
highly pleased" with the makeup
of the group.
Il think the Presidents choices
guarantee fair and dispassionate
report" he said