Largest Thermonuclear Bomb (Full Episode) | Drain the Oceans | National Geographic

Key Concepts

• Nuclear fission bombs (atomic bombs)
• Thermonuclear weapons (hydrogen bombs)
• Operation Crossroads (Able and Baker tests)
• Castle Bravo test
• Radioactive fallout
• Nuclear deterrence
• 3D sonar mapping

Operation Crossroads: Atomic Tests at Bikini Atoll

Background and Purpose

• In 1945, the U.S. detonated atomic bombs on Hiroshima and Nagasaki, Japan.
• In 1946, the U.S. military initiated Operation Crossroads, a series of nuclear tests at Bikini Atoll in the Marshall Archipelago, approximately 5,000 miles from the west coast of America.
• The goal of Operation Crossroads was to understand the nature of war in the atomic age and assess the impact of nuclear weapons on naval fleets.
• The operation involved 42,000 personnel and a fleet of over 240 ships, with 95 ships designated as targets.

Test Able

• Test Able, conducted on July 1, 1946, involved an air detonation of a 23-kiloton fission bomb named "Gilda," identical to those used in Hiroshima and Nagasaki.
• The target was the battleship USS Nevada, painted bright orange for visibility.
• The bomb missed the Nevada by half a mile.
• The USS Gilliam, an Attack-Transport ship, was the first ship to take a direct hit from a nuke.
• The explosion flash-melted the Gilliam, crushing it and causing it to sink.

Test Baker

• Test Baker, conducted three weeks after Able, was the world's first underwater nuclear detonation.
• The purpose was to assess the impact of an underwater explosion on a fleet at anchor.
• A 23-kiloton atomic bomb, nicknamed "Helen of Bikini," was detonated 90 feet below a landing ship, the LSM-60.
• The USS Pilotfish, a Balao Class attack submarine, was positioned 400 yards from the center of the blast.
• The Pilotfish's pressure hull failed due to the blast waves, causing it to sink.
• The USS Saratoga, an aircraft carrier, was located 300 yards from the detonation point.
• The Saratoga was washed sideways by atomic tsunamis and ultimately sunk due to the collapse of a vaporized sand column.

Findings and Consequences of Operation Crossroads

• Operation Crossroads demonstrated that an atomic bomb could not destroy an entire naval flotilla, which was a surprise and disappointment to some observers.
• The most significant effect of the blasts was the spread of deadly radioactivity across Bikini Atoll.
• Radioactivity levels were so high that Operation Crossroads was shut down prematurely.
• The tests led to the Cold War atomic arms race.

Castle Bravo: Thermonuclear Test at Bikini Atoll

Background and Purpose

• In 1952, the U.S. planned new tests at Bikini Atoll involving a hydrogen bomb.
• The hydrogen bomb harnesses nuclear fusion, which is much more powerful than nuclear fission.
• The first test was called Castle Bravo, using a device code-named "Shrimp."
• The planned explosion was to produce a 5-megaton explosion, equivalent to 5 million tons of TNT, 300 times bigger than the Hiroshima bomb.
• The target was the landmass of Bikini Atoll itself.

The Explosion and Its Aftermath

• The Bravo device was accidentally loaded with twice as much active nuclear fuel as planned, resulting in a 15-megaton explosion.
• The explosion created a gigantic crater over a mile across.
• The thermonuclear effects were felt far beyond Bikini, with radioactive fallout spreading for thousands of miles across the Pacific.
• Inhabited islands were affected by the fallout, causing radiation sickness and long-term illnesses among the Marshall Islanders.
• The Bravo explosion filled the world with fear and escalated the arms race.

Long-Term Consequences

• Bikini islanders still cannot return to their home due to radioactivity in the soil.
• The fallout from Castle Bravo has had a lasting impact on the environment and the local population.

Nuclear Deterrence and the Balance of Terror

• In 1961, the Soviet Union detonated the Tsar Bomba, a 50-megaton device, the largest nuclear explosion ever.
• In 1963, world leaders agreed to limit nuclear tests in the atmosphere.
• By the 1980s, there were tens of thousands of nuclear weapons on the planet.
• Today's nuclear weapons are more about accuracy than size, with multiple warheads mounted on long-range ballistic missiles.
• Nuclear weapons may have helped prevent war by creating a balance of terror.

Conclusion

The nuclear tests on Bikini Atoll, including Operation Crossroads and Castle Bravo, had a profound impact on the world. They demonstrated the destructive power of nuclear weapons, led to the Cold War arms race, and created a balance of terror that continues to shape global politics. The tests also had devastating consequences for the environment and the people of Bikini Atoll, who still cannot return to their home due to radioactivity.