Operation Greenhouse
John Siko
©
Copyright 2023 by John Siko
|
Photo from Operation
Greenhouse
US Nuclear Test Media Galley |
In
March 1951, I was one of the crew of 265 officers and enlisted men on
board the USS Walker, a Navy destroyer. I enlisted in August 1950 at
17, right out of high school, and this was my first deployment. The
ship is anchored in a lagoon of the Enewetak Atoll after completing a
three-day voyage from Pearl Harbor. On the journey, all crew members
were told to turn in their cameras, write home, and tell them you
would not be writing again during our deployment. Our sister ship,
the USS Spronsen, and four other navy vessels have been designated
Task Force 3. Our anchorage is off the main island of Enewetak, a
coral atoll consisting of a land area of 2.3 square miles with a
maximum height of 5 feet above sea level. The atoll is one of the 40
islands in the Pacific Ocean that make up the Marshall Islands. For
you historians, in the Battle of Eniwetak occurring in February 1944,
the Americans captured the island in a five-day amphibious operation
against the Japanese Army.
This
coral atoll will be our liberty destination for the next three months
when we could leave the ship. The atoll had hundreds of army soldiers
and civilians billeted there. It did have an outdoor movie and a
large rec center with games, food, and beer. A small landing craft
would make the rounds of the six ships in the lagoon and pick up the
sailors going ashore. A happy crowd that was glad to meet the crews
of other boats while making the short trip.
The
leading entertainment was swimming in the crystal-clear water of the
atoll, where you could view the beautiful coral on the ocean floor.
The other main activity was drinking the free beer. Being able to
swim and drink beer in the four hours we were allowed to remain on
shore, the latter activity became a problem. With the landing craft
taking the crews back to their respective vessels, the incoming
thirty sailors who were so friendly to other sailors on the way into
shore turned into a very unfriendly crowd on the way back. A few
inebriated sailors did not think highly of swabbies from other ships,
and there were many “my ship is better than your ship”
battles before the landing craft deposited the crews to their ships.
Why
were we there, you ask. The two destroyers were assigned to keep all
other vessels out of the fifty square miles of Pacific Proving
Grounds. This was to ensure no fishing vessels entered, and when we
encountered one, we would steam alongside and, with a bullhorn,
inform them to change course. Most understood to leave, but one
either did not understand or just ignored our request, and it took a
shot across his bow to get his attention. There were also two
so-called Russian fishing boats containing many antennas and radar
gear, which is not equipment generally found on a fishing boat. These
were Russian spy vessels that cleared the restricted area when we
approached. They were very interested in the activities on the coral
islands surrounding Enewetak, as I am sure you are also. The USS
Walker was now a participant in OPERATION GREENHOUSE.
A
little history. The Soviet Union surprised the world with its first
nuclear detonation in 1949, much sooner than American scientists had
expected. This spurred the United States into an all-out effort to
stay ahead of the Soviet Union by developing the much more powerful
hydrogen bomb. This thermonuclear device derived its explosive energy
from the fusion of hydrogen atoms. The objective of OPERATION
GREENHOUSE was to proof-test the thermonuclear triggering process, an
essential step toward a successful thermonuclear detonation of the
hydrogen bomb. In addition to the weapons development experiments,
the Department of Defense conducted tests of nuclear weapons'
physical and biological effects. The primary goal of the testing was
to reduce the size and weight and, most importantly, reduce the
amount of fissile material necessary for nuclear weapons while
increasing the destructive power. After the Soviet Union’s
first atomic test, the US had begun stockpiling the new designs
before they were proven; thus, the success of this testing was vital
before the development of thermonuclear weapons could continue. It
should now be apparent why the Russians were so interested and the
importance of the destroyers keeping them from getting the
intelligence they sought.
The
ship knew when a nuclear test was to occur, and we were dispatched on
that day to proceed to a destination to seek to jam the Soviet
intelligence devices. We knew the time and place of the detonation
and steamed upwind of the blast. The first test was scheduled for
April 8 and was named Shot DOG and was a proof test of a Mk 6
strategic bomb. The bomb was 60 inches in diameter, 128 inches long,
and weighed 8500 pounds. The Mk 6 was the US's first nuclear weapon
stockpiled in large numbers. The nuclear device would be atop a
330-foot tower to simulate air bursts and was conducted on Runit
Island, one of the many islands in the Atoll. The shot would yield 81
kilotons, with one kiloton equal to releasing one thousand tons of
TNT. Before the detonation, all crew members turned their back to the
blast island. One could not face the burst without wearing welder
glasses because doing so would be like looking into the center of the
sun. The blast wave arrived about 45 seconds after the initially
silent flash before the sound of the blast did. At that time, we
could face the blast. Initially, I saw a gigantic mound of dust and
then the mushroom cloud rising into the sky. The explosion lifted
250,000 tons of soil to an altitude of approximately 35,000 feet.
Shortly after the blast, it was the crew’s job to hose down all
exposed areas of the ship to remove the radioactive fallout from the
bomb. It was later determined that the fallout from DOG was more
significant than expected. This was caused by a wind shift in the
hours after the detonation to double back on the atoll and
contaminate the ships at sea. We then steamed back to our anchorage
to await the subsequent scheduled burst.
The
second burst (the AEC referred to blasts as bursts) was scheduled for
April 21 on the atoll of Enjebi Island and was named Shot EASY, and
was the proof test of the TX-5D bomb and was a significant advance in
weight reduction for implosion bombs weighing 2700 pounds with a
40-inch diameter. It was also on a 300-foot tower with a burst yield
of 47 Kilotons. Enjebi was one of the larger islands in the atoll,
which allowed the DOD to do an extensive structural response program
in which many full-sized and scaled-down dummy structures were built
at varying distances from the shot point. The structures, sample
buildings, and aircraft parts were heavily instrumented to record
their response to the nuclear burst. Also, the DOD conducted the most
extensive biotic tests program using a variety of plant specimens, as
well as mice, pigs, dogs, and other animals. Again, before the burst,
the ship was dispatched to jam Soviet spy ship information gathering
equipment. My viewing of this burst was the same as DOG, and it was
just as challenging to detail the spectral. Although the radiation
fallout was less significant than DOG, the ship had to be
decontaminated. Once again, shortly after the test, we returned to
our anchorage.
Shot
number three, named Shot GEORGE, was conducted on Eleleron Island on
May 9. It was a thermonuclear physics experiment and was the first to
use external initiation to begin the fission chain reaction. It was
more like a “boosted” nuclear bomb than a thermonuclear
one. Like the others, the device was mounted this time on a 200-foot
tower and was to yield 225 kilotons, nearly triple the result of any
nuclear device detonated up to that time. The explosion left a crater
in the coral and sand atoll 1140 feet across and 10 feet deep.
Because of the large yield, the winds had to be constantly from the
south before detonating, ensuring fallout would blow away from the
atoll. Once again, my viewing of this burst was indescribable.
Shot
number four, designated Shot ITEM, was conducted on May 25, again on
Enjebi Island. This device was also on a 200-foot tower with a burst
yield of 45.5 kilotons. This was the first test of the principle of
fusion boosting of fission devices. Again, the ship returned to its
designated location to jam Soviet information gathering. This test
was moved up 3 hours because of unfavorable winds predicted for later
in the morning. Even so, high-altitude winds blew fallback onto the
residence islands and our ship. The ship’s crew now had the
task of initiating decontamination procedures, and the water washdown
systems could quickly remove the fallout.
Safety
standards were established to limit the exposure of participants to
the effects of nuclear detonations while, at the same time, allowing
them to receive the sometimes unavoidable small doses of radiation as
they performed their missions in the radiation areas. Based on film
badges worn by select personnel, the radiation fallout doses range
from 0.6 to 1.3 rem. As a basis of comparison, a standard diagnostic
chest X-ray delivers a radiation dose of about 0.02 rem. My service
record shows I have been exposed to radiation, but the amount is
unknown. All I know is I don’t need a night light at home.
Our
ship’s assignment to OPERATION GREENHOUSE ended in June 1951,
and the vessel proceeded to Sasebo, Japan. The USS Walker was then
assigned to Task Force 77, where we spent the next six months
shelling the coast of North Korea, the first of two eventual
deployments to Korea.
Photos
of the bursts can be found on the website “Operation Greenhouse
US Nuclear Test Media Galley.”
I am a ninety-year-old
Korean war navy veteran who enjoys writing
short stories when not out on the golf course
(Unless
you
type
the
author's name
in
the subject
line
of the message
we
won't know where to send it.)
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