The Lucky Dragon Incident & Bravo Nuclear Tests

On a calm night at sea in March 1954, 23 Japanese fishermen were aboard their trusty vessel Daigo Fukuryū Maru, (Lucky Dragon 5).

There was a flash in the predawn sky followed a few minutes later by a rumble and those on deck thought it strange as no storm had been forecast.

2 hours later, white flakes of fine ash began to rain down. This lasted for several hours, during which time the fisherman stopped work as they started to feel unwell.

As they steered the boat back to Japan, they began to experience nausea, skin burns, bleeding gums, and eye pain. They would soon find out that they had acute radiation poisoning.

The US military had just detonated its “Bravo” nuclear bomb from its testing site in the Marshall Islands. The Lucky Dragon crew were well outside the danger zone, but the test had been twice as powerful as predicted.

The U.S. Castle Bravo Nuclear Test

8 years into the U.S Marshall Island tests, the Bravo device was the most powerful bomb the military had ever devised. It was 1,000 times more destructive than the bomb dropped on Hiroshima.

As a result, the fallout plume spread dangerous levels of radiation across a radius of over 100 miles; well beyond the range predicted (and declared publicly in advance) by the U.S authorities.

The Lucky Dragon Incident

The Daigo_Fukuryu_Maru shortly before the incident

The Lucky Dragon 5 encountered the fallout from the nuclear test at Bikini Atoll. Changes in weather patterns only exacerbated the danger as it blew the ash – that was actually white flakes of island coral infused with radioactive material – in their direction.

Due to the time it took to retrieve their equipment (and the fact they were slowly falling ill) it took several hours for them to be free of the fallout zone.

During this time the ash continued to rain down onto their hair and into their faces. Before they understood it was causing them harm, some of the fishermen had scooped the dust with their bare hands. One unfortunate man took a lick, later describing it to be “tasteless and gritty”.

By the time they reached shore and the radioactive symptoms had set in, the crew was calling it death ash.

The fate of the crew

A crew member of Lucky Dragon 5 being treated in hospital. Credit: Unknown author / Public domain

Upon arrival at Yaizu port the crew were immediately diagnosed with acute radiation syndrome and admitted to two Tokyo hospitals.

6 months later, on September 23, 1954, one of the crew members (chief radio operator Aikichi Kuboyama) would die. As the first Japanese victim of a hydrogen bomb his final words were said to be: “Please make sure that I am the last victim of a nuclear bomb.

The incident triggered widespread panic in Japan. The horror and wounds of Hiroshima and Nagasaki were still very raw being less than 10 years previous. There was an understandable worry that more tests and deaths would follow.

There was also fear that tuna contaminated during the Bravo test had made its way into the market.

The crew members of Daigo Fukuryū Maru became emblems of the country’s anti-nuclear movement. With the increasing US nuclear armament in reaction to the cold war, this movement gathered much strength throughout the 1950s.

The Daigo Fukuryumaru Museum

  • Address: 2 Chome-1-1 Yumenoshima, Koto City, Tokyo 136-0081, Japan
  • Phone: +81 3-3521-8494
  • Website

The Lucky Dragon 5 today

After years held in storage away from the seas, the Daigo Fukuryū Maru was deemed safe for public viewing in 1976. It is now on display in Tokyo at the Daigo Fukuryū Maru Exhibition Hall.

Its fading hull is accompanied by strings of paper cranes and a Geiger counter. There is also a small jar containing specks of the deadly ash that fell from the sky and onto the boat and crew in March 1954.

Gallery Credit: Guilhem Vellut CC BY 2.0 / Featured Image: Federal government of the United States / Public domain

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