Your browser (Internet Explorer 7 or lower) is out of date. It has known security flaws and may not display all features of this and other websites. Learn how to update your browser.


Bikini Bombshell: The First H-bomb Test on the Eniwetok Atoll

On November 1st, 1952 the United States detonated the world’s first hydrogen bomb on a large atoll called Eniwetok in the Marshall Islands in the South Pacific (190 miles west of the more famous Bikini Atoll) as a part of Operation Ivy. Previously in September of 1949, the Soviet Union had detonated its atomic bomb, prompting the United States to increase efforts to develop an even greater thermonuclear weapon to surpass the capacity of the Soviets. The creation and detonation of the first hydrogen bomb on the Eniwetok atoll allowed the United States to temporarily step ahead of the Soviets during the arms race. Overall there were 43 nuclear tests conducted at Enewetak from 1948 to 1958. H-bombs, which get their power from fusion, are about 1000 times more powerful than atomic bombs, which derive their force from fission.

Colonel Anthony J. Perna was Deputy of the 509th Composite Bomb Wing after the end of WWII. He was assigned to organize Operation Crossroads, a program on the island Kwajalein in the Marshall Islands of the Pacific to set up the Bikini bomb test. Prior to his Deputy position he was a Commander of a B-29 school at Denver, Colorado. Perna was present during the bombing on Eniwetok atoll and describes his experiences.

Go here to read about the July 1945 Trinity test at Los Alamos and when the U.S. accidentally dropped four H-bombs over Spain.


“I was convinced when I saw the thing go off that you could never use them”

PERNA: The war ended in August ’45 when they dropped the bomb on Hiroshima and Nagasaki. In January 1946, a couple months later, I joined the unit that had dropped the bomb, and I became Deputy of the 509th Composite Bomb Wing. We organized a program to go to an island called Kwajalein in the Pacific in the Marshall Islands where we set up the Bikini bomb test. The Bikini bomb test was called Operations Crossroads. This was a program to detonate a nuclear weapon under scientifically controlled and test conditions. The ones we had detonated heretofore was the test one in White Sands (the first one that went off), and then the second one was the one we dropped on Hiroshima, and the third one was dropped on Nagasaki. There was no test data to speak of, so we set up this test program and dropped one from an airplane onto a target ship, the Nevada. We had a whole fleet of navy vessels, a whole bunch of army buildings, and army materiel, including guns and tanks, etc….

Q: To be destroyed?

PERNA: Everything to be tested, to see what happened when you dropped a nuclear weapon. We dropped from 30,000 feet. I did not fly the airplane that dropped it. I was flying an airplane around the target site and I had what we call blast gauges in my airplane. When we came down to the point that they were going to release the bomb, I released these blast gauges. Other pilots with other bombers like mine released blast gauges and with telemetering equipment and radio transmission they were able to record the blast and the data scientifically so that they could find out at various altitudes how much intensity you had from the burst of the bomb.

Q: How far away were you from the blast?

PERNA: I was eleven miles slant range. When the bomb went off here and I was eleven miles at 28,000 feet. We wore goggles for fear of retina damage to the eyes. When the shock wave hit us the whole airplane jerked. It felt like someone took a tremendous plank and slammed it against the airplane, and this was at 11 miles. Well, we stayed out there for the second shot which was where we put a weapon on a tower again up at the Bikini lagoon and we set it off on a tower about 200 feet above the ground.

Q: This was how much later?

PERNA: This was just a matter of weeks, a month later. We did a test in April and May, and then we came home in the summer. We had to produce all the scientific data and recording material that we had. We had a tremendous array of instrumentation from Los Alamos and from all the scientific community in America, including some of the scientific colleges. These people were under contract to the War Department and recording the data to see what would happen. We had animals, we had materiel, we had structures, we had medicines, we had everything you can think of that somebody wanted to see what were the effects of a nuclear detonation.

This was a very impressive moment in my life and I was convinced when I saw the thing go off that you could never use these. Then I spent the rest of my life hauling them around as part of the deterrent against the Russians. But I was convinced when I saw that one go off that this was not the answer for mankind. But we used the threat of them as a successful deterrent.

This Kwajalein “Crossroads” duty with the 509th lasted until the summer when we got our data together, then packed up and came back to Roswell, N.M. and Washington and turned in our report. I delivered the Air Force report called “The employment of nuclear weapons by the US Air Force” to the Air Force headquarters. This was Top Secret in those days. A lot of service politics were involved and interesting at the time.

The weapons had large explosive charges put in a casing, they called them “Fatman.” The Fatman was probably 5 or 6 feet high, probably 8 or 10 feet long. In the core of it was where the uranium went. This was the material that caused the fission, but to make it detonate you had to have an implosion of all the high explosives. When it exploded inward, it made the U-235 go critical, and you caused the fission phenomena. The ingredients U-235 capsule that went inside was controlled by the Navy. We had a Navy Admiral on board our Air Force airplane, Admiral Parsons, who was the man who had inserted it on the flight to Hiroshima. So the Air Force did not have control of the whole thing, the Navy had control of the critical ingredients of the bomb, and he had to wait until we took off, and when we got in flight….

Q: It was inserted in flight?

PERNA: It was inserted in flight, when you were at low altitude and didn’t need oxygen to get in the bomb bay to put the thing in. This was a very interesting period. We had everybody in the world out there looking at the test.

The nuclear testing on Eniwetok had major effects on the health of its inhabitants and the environment of the atoll. Marshallese people claim that they have suffered cancers and thyroid problems as a result of this nuclear testing. In 1983 the United States and the Government of the Marshall Islands agreed upon and signed the Compact of Free Association. This agreement seeks compensate for the damage and injury caused by the nuclear testing on the Bikini Islands. Originally the compact required the United States to establish a $150 million trust fund to the Marshallese government. This amount was later revised to $244 million after nuclear soil testing was conducted in 2000 by the Nuclear Claims Tribunal. The attempts toward environmental restoration have been successful in reducing the amount of radiation by filtering and replacing the topsoil of the island. Further efforts are still in progress as of today to continue to improve the quality of life on the islands.