the explosion crater : 2000 m wide

This is the story of the biggest atomic bomb tested by the USA, the second biggest atomic bomb ever as well as the story of a design mistake that provoked a massive nuclear accident. And I knew nothing about it...

Castle Bravo was the code name given to the first U.S. test of a thermonuclear hydrogen bomb device, detonated on March 1, 1954, at Bikini Atoll, Marshall Islands, by the United States. Castle Bravo was the most powerful nuclear device ever detonated by the United States, with a yield of 15 Megatons. That yield, far exceeding the expected yield of 4 to 6 megatons, combined with other factors to produce the worst radiological accident ever caused by the United States.
In terms of TNT tonnage equivalence, Castle Bravo was about 1,200 times more powerful than the atomic bombs which were dropped on Hiroshima and Nagasaki.Fallout from the detonation—intended to be a secret test—poisoned the islanders who inhabited the test site, as well as the crew of Daigo FukuryĆ« Maru ("Lucky Dragon No. 5"), a Japanese fishing boat, and created international concern about atmospheric thermonuclear testing.

remains of the bunker on the island

When Bravo was detonated, it formed a fireball almost four and a half miles (roughly 7 km) across within a second. This fireball was visible on the Kwajalein atoll over 250 miles (450 km) away. The explosion left a crater of 6,500 feet (2,000 m) in diameter and 250 feet (75 m) in depth. The mushroom cloud reached a height of 47,000 feet (14 km) and a diameter of 7 miles (11 km) in about a minute; it then reached a height of 130,000 feet (40 km) and 62 miles (100 km) in diameter in less than 10 minutes and was expanding at more than 6 kilometers (4 miles) per minute.

Unanticipated fallout and radiation also affected many of the vessels and personnel involved in the test, in some cases trapping them in bunkers. Sixteen crew members of the aircraft carrier USS Bairoko received beta burns and there was a greatly increased cancer rate. Radioactive contamination also affected many of the testing facilities built on other islands of the Bikini atoll system.

The fallout spread traces of radioactive material as far as Australia, India and Japan, and even the US and parts of Europe. Though organized as a secret test, Castle Bravo quickly became an international incident, prompting calls for a ban on the atmospheric testing of thermonuclear devices.

The following pictures are remains of various ships wrecked during atomic bomb test in the Bikini Atoll, some by accident, some on purpose : USS Saratoga ,USS Lamson, USS Anderson, USS Apogon. Some of the most beautiful underwater pictures you could ever see.

coordinates : 11°41'46.57"N 165°16'21.17"E
google map

pictures sources : 1 2 34 5 6
text source : 1 2 3 4 5

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  1. Gunnar and Sherry // Monday, December 08, 2008 12:22:00 PM  

    Fantastic post! Those underwater photos of the ship are amazing, especially the phones and the helmets. Very, very surreal. On a somewhat lighter note, I recently visited the Atomic Testing Museum in Las Vegas, a very interesting place. Here's my post:
    Keep up the good blogging!

  2. Anonymous // Monday, March 02, 2009 12:11:00 PM  

    The ships were not sunk by accident, as per the report, but deliberatly by the Able and Baker blasts in 1946 (Operation Crossroads.)

    Additionally, the Castle Bravo test did not "poison the islanders who inhabited the test site," because the Bikini islanders had been moved off the atoll for the 1946 blasts. Because of radiation and subsequent blasts, they had not returned in 1956. Anyway, the Bravo blast vaporized three islands in the atoll, and certainly no islanders were living on them.

    Rongelap Atoll (about 100 miles from Bikini) is famous for having received a rather unhealthy and unplanned snow of fallout from Bravo, because the blast was carried out in spite of the wind that day not blowing in the expected direction. Perhaps that is the confusion.

    A good synopsis of the nuclear history of Bikini, as well as info on the sunken ships in the lagoon, can be found here for reference: and

  3. Third Eye // Monday, April 20, 2009 11:23:00 AM  

    Awesome report, the quality of the shoot is so vivid and yet so macabre in their vintage feel.

    Thanks for the post!