U. S. S. Haven (AH-12)
4 July 1946
[Address]
Dear Mr. President:
Your Evaluation Commission, divided between pos-
itions at sea and in the air, witnessed the first
Bikini test, at 33 seconds after 9:00 a.m. local time
on
July 1, and has since completed a survey of
the
damage. The second test, wherein the bomb will be
exploded under water, will in some respects be of
even greater interest, for it will have no precedent.
The report of your Commission required by its direct-
ive of
May 18 must await assembly of considerable
data deriving from instrumental and photographic
measurements and analysis of fission product samples.
However, we believe that it lies within the
scope of your directive and may be of possible assist-
ance to you, to submit, now, the following brief
observations made from the layman's point of view,
but with such accuracy as is presently available:
1. The organization and execution of the oper-
ation was magnificently handled and has commanded
our continuous admiration. The bomb was dropped
under favorable weather conditions about 30 seconds
after the time set. The greatest credit is due
Admiral Blandy and the
officers and enlisted personnel
of both services who, with scientists and other civ-
ilians, have served and are serving under him with
a display of team work that must be seen to be fully
appreciated.
2. Their conservatively safe distance from
the burst led many observers to entertain an initial
opinion that the bomb employed was somewhat under
par. It is now, however, safe to state that the
energy was of the same order of magnitude as in the
case of previous atomic detonations, between the
highest and lowest of this bomb's three predecessors.
3. The accuracy of the drop was such that
the explosion occurred withing the area included with-
in the allowance for the probable error of the elev-
ation of drop, and detonation was probably within
one hundred feet of the chosen altitutude. Nevertheless
the explosion actually occurred several hundred yards
west of a point directly above the target ship Nevada,
and therefore entirely west of the closesly spaced
array of capital ships.
4. There were 90 targets anchored in the lagoon
when the bomb exploded. These were not in battle
formation but were placed in positions to give the
largest amount of desired technical information with
especially close concentration around the center
target point. Those ships anchored a mile or more
from the point of drop largely escaped injury. Those
within a mile were sunk or suffered damage varying
with the distance from the point of detonation and
with the type of ship construction. On explosion,
a destroyer and two transports sank promptly. A
second destroyer and the Japanese cruiser Sakawa
sank within 27 hours. The light carrier Independence
was gutted with fire and resultant explosions. The
submarine Skate was heavily damaged and later towed
away. All of these were near the point of explosion.
The other ships including the only two capital ships
which were within one half a mile of the detonation
received damage that would require more or less
complete overhaul and in most cases repair at major
bases before they could again be used for combat.
A study of this damage will point the way to changes
in design which should minimize damage from blast
and heat. Beyond these ships there was extensive
damage to superstructure, radar, and fire control.
Had the ships within the damage area been manned,
casualities and psychological injuries would have
required large per centage of replacements.
Until the readings of complex instruments and
the future life history of animals within the ships
have been determined no accurate appraisal of poten-
tial damage to human life within the ships can be
made.
5. No wave or blast damage could be noticed
on
Bikini Island which is approximately three miles
from the point of detonation.
6. We are of the unanimous opinion that the
first test amply justified the expenditure required
to conduct it and that the second test is equally
desirable and necessary. You made a wise decision
when you approved the plans for these tests and
they have been carried out with extraordinary skill
diligence and ingenuity. The test just completed
has again proven that the atomitc bomb is a weapon
of terrific power when used on land or sea.
CARL A. HATCH,
Chairman,
For the committee.
After further study of ship locations and point
of detonation I believe we may have been somewhat
inaccurate in the following sentence:
"The other ships including the only two
capital ships which were within one half
a mile of the detonation received damage
that would require more or less complete
overhaul and in most cases repair at major
bases before they could again be used for
combat."
One half a mile from the point of detonation might
possibly include ships which would require but
little repair. From 500 to 700 yards, in my opinion,
would have been a more accurate statement. Even
so, the sentence is justified for we do use the
qualifying words "more or less" and "in most cases".