The 50s and 60s

The 50s and 60s

The end of World War II brought a new struggle—the Cold War. The United States and the Soviet Union engaged in an arms race. A diverse range of nuclear weapons were designed for transport in high-speed, high-altitude aircraft. Smaller, lighter weapons placed less drag on aircraft, which could then fly greater distances. Between 1951 and 1956, underwater capabilities and smaller nuclear shells were developed too.

In 1957 and 1958, the United States designed nuclear weapons to defend against aircraft attacks as well as developing anti-ship or anti-submarine bombs. Yield increased to the megaton range. The same weapon could be dropped from very high or very low altitudes. Between 1958 and 1961, the U.S. nuclear arsenal also stockpiled anti-ballistic missiles.
Fusion weapons were developed in the 1950s. In simple terms, a fusion weapon uses an atomic bomb and hydrogen to trigger an explosion of great size. A fusion weapon is often referred to as a hydrogen bomb.

Edward Teller pioneered work on fusion. Edward Teller managed Los Alamos research on the “Super,” as he called the hydrogen bomb. Destruction of Hiroshima and Nagasaki in Japan and the end of World War II slowed “Super” research. Teller, a strong anti-Communist and sensitive to U.S. and Soviet relations, pushed unsuccessfully to accelerate work on a super-bomb. He was frustrated by the post-war direction of Los Alamos. He accepted a University of Chicago professorship and left Los Alamos in October 1945.

April 1946, Teller returned to Los Alamos and led a secret conference on the “Super.” The conference reviewed his earlier work on fusion, which led to his full-time return to Los Alamos in 1949 to continue research on the hydrogen bomb. On January 31, 1950, President Truman approved hydrogen bomb development and testing, partly as a result of the first Soviet atomic test the previous August.

The Mark 17 is the largest U.S. nuclear weapon ever built. The mighty Mk 17 was the United States first droppable thermonuclear weapon or H-bomb. Quite crude by today’s standards, it was extremely large and heavy; its massive 25-foot long steel casing was approximately 3.5 inches thick and weighed almost 21-tons. Size wise, the Mk 17 was the largest nuclear weapon ever built by the United States.

When the Mk 17 was test-dropped, the pilots said it was as if the bomb had released the aircraft, since suddenly lightened of the heavy weapon the plane would soar hundreds of feet as the pilot’s fought to regain control. In combat a gigantic 64-foot diameter ribbon parachute was designed to slow down or retard the big bomb giving the delivery aircraft time to escape the deadly effects of the thermonuclear explosion.

The yield of the Mk 17 was in the megaton range – a megaton (Mt) being the explosive equivalent to one million tons of TNT. The bomb was at one time referred to as a Mk 17/24 because the same weapon case was used for both of these early weapons. The only differences between the Mk 17 and the Mk 24 were internal.

The Davy Crockett was one of the smallest nuclear weapons ever made. The Davy Crockett was a bazooka-type missile with a W54 nuclear warhead. It could be mounted on a Jeep, or a three-person team could carry it. The weapon system used a spin-stabilized, unguided rocket fired from a recoilless rifle. While early atomic missiles were heavy and awkward, the Davy Crockett was only 30 inches long, 11 inches wide and weighed 76 pounds.

Two types were made: a 120-mm with a range between 1,000 to 6,500 feet; and a 155-mm with a range between 1,000 to 13,000 feet. The Davy Crockett also could carry a conventional high-explosive round for use as an anti-tank weapon. Stockpiled from 1960 to 1971, the Davy Crockett brought nuclear capability to the infantry.

On January 17, 1966, a Strategic Air Command B52 had a mid-air collision with a KC135 tanker while refueling over Palomares, Spain. On January 17, 1966, an SAC B-52 had a mid-air collision with a KC-135 tanker while refueling over Palomares, Spain. The B-52 was carrying four thermonuclear B28 bombs. The bomber had begun the mission at Seymour Johnson AFB, North Carolina. The KC-135 had come from the Moron Air Base, Spain. All four KC-135 crew members were killed, while four of the seven B-52 crew parachuted to safety.

President Lyndon Johnson, the Department of Defense, the Atomic Energy Commission, and the Spanish Government received news of the nuclear accident. Nuclear safety teams were dispatched immediately. Within hours, the 16th Air Force had located the three B28 bombs that landed on the shore. However, the fourth bomb was missing; it was not found for 80 days. High explosives in two bombs had detonated on impact. Plutonium dust had spread over several hundred acres. One reassuring fact emerged from this incident: inherent safety features designed and built by Atomic Energy Commission contractors ensured that no nuclear explosion occurred.

Tokutaro Hagiwara
(May 1941)
Tokutaro Hagiwara, a Japanese physicist, first proposed the idea of fusion.

Enrico Fermi
(September 1941)
Fermi made a suggestion to Hungarian physicist Edward Teller that that an atomic or fission bomb might produce enough energy to heat a mass of hydrogen. That, in turn, would trigger a fusion explosion.

Edward Teller
(April 1946)
Teller returned to Los Alamos and led a secret conference on a hydrogen super-bomb.

Soviet Union
(August 1949)
In August 1949, the Soviet Union exploded its first nuclear weapon, “Joe One.” Its development was years ahead of American military-intelligence projections.

President Truman
(January 31, 1950)
President Truman ended the hydrogen-bomb debate and approved development and testing.

Operation Ivy
(November 1, 1952)
America first tested a hydrogen bomb during Operation Ivy. On Nov. 1, 1952, its “Mike” shot occurred at the Atomic Energy Commission Eniwetok Proving Ground in the Marshall Islands of the South Pacific. This escalated the Cold War. The hydrogen bomb led to more nuclear weapons of varying size, design, and yield.