Know Your Nuclear History

from Trinity to the end of the Cold War

Part One

Take a break from your global thermonuclear war and learn a bit about where those nukes you're launching came from. Los Alamos National Laboratory has some information on the very first atomic test, codenamed Trinity.


At 5:29:45 am Mountain War Time on July 16, 1945, the world's first atomic bomb exploded one hundred feet over a portion of the southern New Mexico desert known as the Jornada del Muerto - the Journey of the Dead Man. On seeing the fireball and mushroom cloud, J. Robert Oppenheimer recalled a passage from the Bhagavad-Gita: "I am become death the destroyer of worlds." Trinity Test Director, Harvard Physicist Kenneth Bainbridge, had a less ethereal reaction, saying, "Now we are all sons of bitches."

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The Trinity test was the first ever test of a nuclear device

A New Method: Implosion
In the first months of operations at Los Alamos in the spring of 1943, Oppenheimer and others believed that the first atomic bomb would be a gun that would shoot one piece of uranium or plutonium at a second piece of identical material. When the two pieces came together, a nuclear explosion would take place. From April 1943 until mid-summer 1944, almost all work at Los Alamos centered on designing and building such a gun. Experiments directed by future Nobel Prize winner Emilio Segre, however, demonstrated that plutonium could not be used in a gun. Impurities in the metal, which could not be removed, would cause a fizzle. It seemed, for a short time, that plutonium could not be used to make an atomic bomb. Because of serious problems in producing uranium, the plutonium problem put the entire atomic bomb program at risk.
The technical solution to this problem lay in the use of high explosives. Seth Neddermeyer proposed using the supersonic shock waves produced by high explosives to crush, or implode, a ball of plutonium to a supercritical state. If a ball of plutonium could be imploded symmetrically to a supercritical state, a nuclear explosion would follow. Seeing the technical merit of this approach, Oppenheimer reorganized the Los Alamos Laboratory in the summer of 1944 to concentrate work in this area. However, since this possible solution was new and untried, a test of such a gadget would be necessary.

Where Will it be Tested
Once the decision to test the implosion gadget was made, a test site had to be selected. Eight locations were proposed and evaluated:

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Trinity Test Site

1. The Tularosa Valley in southern New Mexico
2. The Jornada del Muerto, also in southern New Mexico
3. The Army's desert training area near Rice, California
4. San Nicholas Island, off the coast of Southern California
5. The lava region south of Grants, New Mexico
6. An area in New Mexico southwest of Cuba, and north of Thoreau
7. Sand bars, about 10 miles from the main coast of southern Texas
8. The San Luis Valley region near the Great Sand Dunes National Monument in southern Colorado

Bainbridge used five criteria in evaluating these sites. First, the area had to flat to minimize effects on the blast. Second, the weather needed to V Site,, with little dust, haze, or strong winds. Third, the area needed to be remote from populated areas. Fourth, the site had to be relatively close to Los Alamos to minimize transportation problems. Finally, the site had to be isolated to enhance security. Using these criteria, Bainbridge narrowed the choice to the Jornada del Muerto, and the Army's desert training area near Rice, California. The Jornada del Muerto close to Los Alamos and easier to acquire, was selected.

The Journey of the Dead Man
Beginning in October 1944, the Jornada del Muerto became the site of ever increasing activity as Trinity Site was prepared for the test. A base camp was built to house staff. A one-hundred foot shot tower was designed and constructed at ground zero. Concrete bunkers to house cameras and other diagnostic equipment popped up in a rough circle around ground zero. Many of these bunkers were given names pegged to their proximity to the shot tower, such as "North 10,000." In March 1945, a July date was set for the Trinity test. However the actual day, July 16th, was not selected until the end of June, when the last of the technical issues had been addressed. In addition, a commitment had been made to test the gadget "as soon after July 15th as possible," and before or during the upcoming Potsdam Conference.

The plutonium was driven to Trinity site on July 11th in the back of Plymouth sedan. The high-explosive sphere, approximately five feet in diameter, followed on July 13th, lashed to the bed of an Army truck. Norris Bradbury, who would succeed Oppenheimer as Director of Los Alamos, wrote the procedures for assembling the gadget. His timetable called for the gadget to be completely assembled and lifted to the top of the tower on Saturday, July 14th. Bradbury's timetable for Sunday, July 15th, reflected both Bradbury's sense of humor as well as the strain everyone felt on the eve of the test. Bradbury wrote, "Look for rabbit's feet and four-leaved clovers. Should we have the Chaplain down there? Period for inspection available from 0900-1000." The timetable for July 16th had just one word - "Bang!"

"A foul and awesome display"
Delayed for a time by a worrisome thunderstorm, the test erupted over the desert floor with what Bainbridge termed "a foul and awesome display." For observers standing from six to ten miles away, the site was fearsome. Enrico Fermi, not wanting to wait hours and days for the complex diagnostic data to be evaluated, decided to conduct an ad-hoc experiment to calculate the yield of the gadget. Wrote Fermi, "About 40 seconds after the explosion the air blast reached me. I tried to estimate its strength by dropping from about six feet small pieces of paper before, during, and after the passage of the blast wave. Since, at the time, there was no wind, I could observe very distinctly and actually measure the displacement of the pieces of paper that were in the process of falling while the blast wave was passing. The shift was about two and a half meters, which at the time, I estimated to correspond to the blast that would be produced by ten thousand tons of TNT." While Fermi's estimate was on the low side, his calculation did prove the enormous energy release was demonstrably more than could be achieved by conventional bombs.

Operation Trinity, the detonation of a bomb called Gadget, was a 20 kiloton blast using a plutonium implosion design. Less than a month later, two atomic bombs were dropped on Japanese cities to end the second world war. The first, named Little Boy, was a 13-16 kiloton uranium gun design bomb. The second, named Fat Man, was another plutonium implosion design and had a yield of 21 kilotons.

It would be a little over 4 more years before the Soviet Union detonated their first atomic, modeled after the Gadget and Fat Man, a 22 kiloton bomb called Joe 1.

Part Two

Trinity was just the beginning. While the Soviet Union was still years off from their own nuclear tests, the United States was busy on a number of operations underwater, in the air, and on the ground. One significant advance was the "boosted" fission bomb, one in which a small amount of fusion fuel is used to increase the explosive yield. Pure fission weapons have a theoretical cap of about 500 kilotons, but boosted fission could be higher (although still in the sub-megaton range). Most significantly, boosted fission weapons were an important step towards the development of the thermonuclear warheads we all know and love.

The following is a declassified (although edited) video used to brief secret oversight committees of the U.S. Congress, detailing tests conducted from 1945 through 1951.

These tests helped scientists and military officials determine the effects of atomic weapons and experiment with various new designs, all marking the way towards the first thermonuclear bomb test in 1952.

Part Three

After the 1949 atomic test conducted by the Soviet Union, President Truman ordered a crash program to develop the thermonuclear bomb. Operation Ivy, a test of two parts, was the detonation of Ivy Mike, the first full test of the Ulam-Teller design hydrogen bomb, and Ivy King, the largest pure-fission device ever tested by the United States.

The following is a video with additional information quoted and linked to below detailing the Ivy Mike test.



"The island of Elugelab is missing!" President Eisenhower heard this short report on the Mike shot in Operation IVY from Gordon Dean, Chairman of the Atomic Energy Commission.

Mike was the first full-scale hydrogen explosive device to be tested, yet was only a scientific test of a thermofusion implosion device concept. Mike was not a deliverable weapon.

The island where the device was detonated was vaporized. The hole Mike left was big enough to accommodate 14 Pentagon-size buildings and deep enough to hold 17 story building under water, in a crater one mile in diameter and approximately 175 feet deep. Mike's yield was an incredible 10.4 megatons, signaling the proof-tested expansion of the nuclear explosive technology concepts from nuclear fission to thermofusion. Thermofusion is the same process that occurs in the core of the Sun.

This test, however, was not the first test of a liquid thermonuclear explosive. The first test ever conducted into the fusion principle occurred during Operation GREENHOUSE at Eniwetok in 1951, with the 225 kiloton George test. Another test of hydrogen in the center of a nuclear weapon before Mike was during the GREENHOUSE Item test at Eniwetok, proving a critical stockpiling yield efficiency concept, called "boosting."

The detonation of the Mike device was the climax of an intense debate over what would be the nation's correct response to the startling news in 1949 that the Soviet Union had detonated a nuclear weapon. Many wanted the U.S. to develop the means to produce and field a large number of fission bombs of varying yields which could be used for tactical purposes. Others believed that the country should institute a crash program like the Manhattan Project to develop a Super weapon based on the idea of forcing together or fusing light atoms with a fissile device to produce enormous amounts of energy.

After a bitter fight among scientific, government and military officials, the President opted for a crash program to demonstrate the Super bomb, now called a hydrogen or thermonuclear weapon. Many designs were evaluated and rejected until the Mike proposal came along. This concept involved the cooling of hydrogen fuel to a liquid form, near absolute zero, and fusing the hydrogen nuclei into helium using a nuclear fission bomb as a trigger.

The Mike device was a 22-foot-long, 5-foot-diameter cylinder housing canisters of liquid hydrogen fuel. These liquid fuel canisters were heavily encased with the nuclear fission explosive trigger.

The Mike shot occurred on October 31, 1952, as scientists watched from 40 miles away as the mushroom cloud rose into the stratosphere.

Mike was followed on November 15, 1952 by the King shot, the largest all-fission device ever tested by the United States. It was a uranium super oralloy Mark 18 prototype implosion core in a Mark 6D casing, with an advanced warhead that enabled it to produce 500 kilotons of equivalent TNT explosive energy.

About the Mike phase narrator:

Reed Hadley narrated and hosted this portion.

Parallel to his public life as a radio, television, and movie star -- with the credit of a star on the Hollywood Walk of Fame -- Reed Hadley worked in a top secret military role as a presenter for Armed Forces Special Weapons Project (AFSWP) films.

AFSWP produced films through the United States Air Force Lookout Mountain Laboratory located in Hollywood, California. These AFSWP films covered analysis and documentary archives in nuclear weapons testing, special weapons systems development, as well as Civil Defense films. A key role of the laboratory was to produce films for national defense projects archives, military training films, and documentation for top secret oversight and appropriations committees of United States Congress.

About the King phase narrator:

Carey Wilson narrated this portion.

Wilson was a very influential producer and scriptwriter in Hollywood -- principally with MGM -- and led a double life role as a "Q-Clearance" presenter and contributing scriptwriter in top secret films produced by the Atomic Energy Commission and the Armed Forces Special Weapons Project (AFSWP).

Q-Clearance was a top secret classification within the Atomic Energy Commission, later renamed to the Department of Energy.

Interviewed in this film was the firing team commander, Stanley W. Burriss. He was an engineer by profession. He later became among the greatest forces for creating the U.S. Fleet Ballistic Missile, and later, critical contibutions to generations of Polaris, Poseidon, and Trident weapons systems. He managed this unprecedented scientific, engineering, and command management undertaking, which had profound effects on the civilian space program. Burriss retired as president of Lockheed Missiles and Space Company, after 25 years with Lockheed, and died in the spring of 1979.

Captain Jack S. Hartwick, appearing near the beginning of the film in the bridge, was the commander of the USS Estes, host to the Mike device firing control and Joint Task Force 132 operations command center.

Major General Percy Clarkson was supreme commander of Joint Task Force 132.

Some notes about filming techniques of 1950s color filming:

1950s color film was not capable of satisfactory sensitivity to light in darkness. A workaround was to film during the daylight, using a blue filter. The low sensitivity to blue light -- the most sensitive was yellow -- of the color film made for dark scenes that simulated nighttime or hours of darkness. Notice the bright reflections of ambient light and the tall shadows during the "hours of darkness" scenes. This was not the moon creating these shadows.

The film's hours of darkness scenes appear very dark in digitized form, played on a personal computer. Burning the DVD file as a data import file (without reencoding in MPEG2!) will have a much brighter picture when played on a home TV or theater system.

Comments concerning DOE/DoD film releases in VHS:

Disappointment and irritation are the common reactions to the DOE release procedure of transferring their Digital Betacam format masters to VHS. This change in colorspace formats creates very pale, horizontal lines in the picture.

The ritual procedure of releasing sanitized and unclassified DOE/DoD films through the Authorized Derivative Declassification (ADD) experts at Kirtland is to edit the transfer of 16 mm celluloid to Digital Betacam master tapes by selectively turning off the capture of audio, video, or both to preserve DOE/DoD secrets. VHS NTSC tape releases are then derived from Digital Betacam tapes.

In addition to the 10.4 megaton Ivy Mike, Ivy King was tested. It was dropped from a plane and exploded with a yield of 500 kilotons, making it the largest pure-fission device. In theory, the Ivy King nuclear warhead could have been used in actual military service had Ivy Mike failed and thermonuclear warheads were deemed a failure.

Part Four

This final segment of the Know Your Nuclear History outlines some of the more... interesting... nuclear tests.

Operation Upshot-Knothole was a series of 11 tests carried out in 1953 after the successful thermonuclear tests the year before. The tenth of those tests, was Grable, because sooner or later somebody was bound to say, "hey, let's make an artillery gun that shoots nukes!"

Atomic Annie, as it was called, could put a 15 kiloton shell 6 miles or so down range.

Later that year, the Soviet Union tested their own thermonuclear bomb, Joe 4. It was a 400 kiloton yield, and while not technically a true hydrogen bomb (more like a boosted fission bomb), it was deployable and marked a significant step in the arms race. The Soviet's RDS-37 in 1955 reached megaton status. In 1961, the Tsar Bomba was tested. It was the largest nuclear warhead ever tested at 50 megatons, and could be scaled to 100 megatons. While impractical, it showed that the Soviet Union was not just a second-rate nuclear power.

Back in the United States, tests were conducted on potential peaceful uses for nuclear weapons. You know, like blowing up a really big bomb to widen the Panama Canal! Operation Plowshare was a series of many Peaceful Nuclear Explosions to test everything from mining to connecting aquifers.

There's also Starfish Prime test, in which a relatively small nuke was exploded just outside the atmosphere in space, which led to an artificial aurora over much of the Pacific and an EMP that knocked out power and communications on the Hawaiian islands. Additionally, 1/3 of all satellites in low orbit at the time were crippled, including the very first commercial communications satellite. Oops!

Since nuclear artillery was so cool, the United States also experimented with something even more fun, nuclear bazookas. Operation Sunbeam tested a number of small nuclear devices including the sub-kiloton recoilless rifle Davy Crockett. This 10-20 ton nuclear fission shell could be fired a couple of miles and take out Soviet tanks invading western Europe.

The US even tinkered with the idea of a nuclear reactor for flight. An unshielded ram-jet cruise missile was devised, capable of months of flight (far away from inhabited areas). In theory this cruise missile could be launched with conventional rockets, powered up with its nuclear reactor over the ocean until ordered to hit targets in the Soviet Union. It was theorized that a warhead would not be needed on this missile, as the radiation leaked from its engine would kill people on the ground as it flew at mach 3 at treetop level over populated areas. That said, Project Pluto could have been used as a sort of unmanned bomber, able to deliver a number of warheads on a number of targets. While successful in preliminary testing, Pluto was shelved by the Pentagon after the ICBM was developed.

Well there you have it. I hope you've enjoyed these four topics as much as I enjoyed putting them together. If you're interested in more nuclear test footage or information, I highly recommend these sites:


Remember folks, Duck and Cover!

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