Daigo Fukuryū Maru

Daigo Fukuryū Maru

Daigo Fukuryu Maru
Daigo Fukuryū Maru on display in Tokyo
  • Daigo Fukuryu Maru
  • ("Lucky Dragon No.5")
Launched: 1947
Status: Museum ship since 1976
General characteristics
Type: Fishing boat
Displacement: 140.86 t (139 long tons)
Length: 28.56 m (93.7 ft)
Beam: 5.9 m (19 ft)
Propulsion: 250 hp (186 kW) engine
Speed: 5 knots (9.3 km/h; 5.8 mph)
Crew: 23

Daigo Fukuryū Maru (第五福龍丸, S.S. Lucky Dragon 5) was a Japanese tuna fishing boat, with a crew of 23 men, which was exposed to and contaminated by nuclear fallout from the United States' Castle Bravo thermonuclear device test on Bikini Atoll, on March 1, 1954.

Aikichi Kuboyama, the boat's chief radioman, died less than seven months later on September 23, 1954, having suffered along with the 22 other crew members of acute radiation syndrome (ARS) for a number of weeks after the Bravo test in March. Kuboyama is considered the first victim of the hydrogen bomb of test shot Castle Bravo.


  • Early days and final voyage 1
  • Events surrounding March 1, 1954 2
    • Events between March 2–14 2.1
    • Events after return to Yaizu port 2.2
  • Medical symptoms and treatment 3
  • Health history of crew 4
  • Radioactivity of the ship post contamination 5
  • Media 6
  • See also 7
  • Notes and references 8
  • Further reading 9
  • External links 10

Early days and final voyage

Built in March 1947, and launched from Koza, Wakayama, the boat's name was originally Dainana Kotoshiro Maru (第七事代丸, Kotoshiro Maru No. 7)/Kotoyo Maru No. 7. Under this title it was a bonito boat and moored in Misaki Fishing Harbor, Kanagawa Prefecture.

It was later remodeled into a tuna fishing boat. In 1953, it moved to Yaizu Port, Shizuoka Prefecture, with a new name, Daigo Fukuryū Maru translated as - Lucky Dragon No. 5, or alternatively, the Fifth lucky Dragon.

Under its new title, the Lucky Dragon No. 5 took five ocean voyages. Its fifth and final voyage began on January 22, 1954, and ended on March 14 of that year. The crew initially set off to go fishing in the Midway Sea near [1]

A map of the varying location of the boat in the days leading up to and after the day of the explosion is available, on March 1 the map depicts the vessel very near to the [1]

The source of the map,[1] does not state how the map was created, that is, it does not state that the [1] Therefore the exact position of the ship on the day of the explosion is uncertain. Contemporary references give a figure of "80 miles east of Bikini Atoll" without stating the method by which the distance was computed.[2][3] According to a 1997 paper by Martha Smith-Norris, the ship was operating "14 miles" outside the 57,000 square mile "Danger Area", and it was not detected by radar or visual spotter planes.[4]

Events surrounding March 1, 1954

Map showing points (X) where contaminated fish were caught or where the sea was found to be excessively radioactive. B=original "danger zone" around Bikini announced by the U.S. government. W="danger zone" extended later. xF=estimated position of the Lucky Dragon fishing boat when fallout began to arrive at their location. NE, EC, and SE are equatorial currents.
The Bravo fallout plume spread dangerous levels of radiation over an area over 100 miles (160 km) long, including inhabited islands. The contour lines show the cumulative radiation dose in roentgens (R) for the first 96 hours after the test.[5]
The Bikini Atoll. The Bravo crater is on the North West end of the atoll, the device's firing crew were located on Enyu island, variously spelt as Eneu island as depicted in this map.
Daigo Fukuryū Maru in early 1950s, shortly before the incident

The Daigo Fukuryū Maru encountered the fallout from the U.S. Castle Bravo nuclear test at Bikini Atoll, near the Marshall Islands, on March 1, 1954. When the test was held, the Daigo Fukuryū Maru was catching fish outside the danger zone which the U.S. government had declared in advance. However, the test was more than twice as powerful than it was predicted to be, and changes in weather patterns blew nuclear fallout, in the form of a fine ash, outside the danger zone.[6] On that day, the sky in the west lit up like a sunset. Seven minutes later the sound of the explosion arrived, with fallout reaching the ship two hours later.[7] The fishermen realized the danger, and attempted to escape from the area, but they took time to retrieve fishing gear from the sea, exposing themselves to radioactive fallout for several hours.

The fallout - fine white flaky dust of calcinated Bikini Island coral, which absorbed highly radioactive fission products and neutron activated isotopes - fell on the ship for three hours. The fishermen scooped it into bags with their bare hands. One fisherman, Matashichi Oishi, reporting that he "took a lick" of the dust that fell on his ship, describing it as gritty but with no taste.[8] The dust stuck to surfaces, bodies and hair; after the radiation sickness symptoms appeared, the fishermen called it shi no hai (死の灰, death ash).

Events between March 2–14

Feeling ill, the crew set sail to return to [1]

Events after return to Yaizu port

Medical professionals, before the era of whole body counting, assessing the activity of a bedridden crew member by using a geiger counter on 31 March 1954, focusing on the persons hair which would have collected dusty fallout.
The inspection of tuna with a geiger counter before sale at a fishmongers on 31 March 1954

Japanese biophysicist Yasushi Nishiwaki immediately traveled from Osaka to Yaizu to examine the crew and their boat. He quickly concluded that the they had been exposed to radioactive fallout and wrote a letter to the chief of the US Atomic Energy Commission (AEC) asking for more information on how to treat the crew. The crew members, suffering from nausea, headaches, burns, pain in the eyes, bleeding from the gums, and other symptoms, were diagnosed with acute radiation syndrome and admitted to two Tokyo hospitals. On September 23, chief radio operator Mr. Aikichi Kuboyama, 40, died — the first Japanese victim of a hydrogen bomb. He left these words: "I pray that I am the last victim of an atomic or hydrogen bomb."[6][9] The US did not respond to Nishiwaki's letter or to letters from other Japanese scientists requesting information and help,[10] although the United States did dispatch two medical scientists to Japan to study the effects of fallout on the ship's crew and to assist their doctors.[11][12]

The bald head of one of the crew on 7 April 1954, focusing on the burn and general skin discoloration.
Kuboyama Aikichi on 15 September 1954. Aikichi would later die on 23 September.
The grieving family of Aikichi.

The US government refused to disclose the fallout's composition due to "national security", as the fallout's isotopic ratios—namely a percentage of uranium-237—could reveal the design of the Castle Bravo device through radio-chemical analysis, with this information having a history of being regarded as potentially revealing the means by which megaton yield nuclear devices achieve their yield.[13] For instance, Joseph Rotblat may have deduced the staging nature of the device by studying the ratio and presence of tell-tale isotopes present in the fallout.[14] As of 1954, the Soviet Union had not yet been successful with thermonuclear staging and such information could have assisted in their development of a thermonuclear weapon. Lewis Strauss, the head of the AEC, issued a series of denials; he also hypothesized that the lesions on the fishermen's bodies were not caused by radiation but by the chemical action of the caustic burnt lime that is produced when coral is calcined, that they were inside the danger zone, and told President Eisenhower's press secretary that the Lucky Dragon #5 may have been a "Red spy outfit", commanded by a Soviet agent intentionally exposing the ship's crew and catch to embarrass the USA and gain intelligence on the tests device.[15]

Later, the United States expanded the danger zone and it was revealed that in addition to the Daigo Fukuryū Maru, many other fishing boats were in the expanded zone at the time. It is estimated that about one-hundred fishing boats were contaminated to some degree by fallout from the test. Despite denials by Lewis Strauss concerning the extent of the claimed contamination of the fish caught by Daigo Fukuryu Maru and other ships, the FDA later imposed rigid restrictions on tuna imports.[16]

The US at first tried to cover up the Lucky Dragon incident, sequestering the victims and declaring them off limits. Later the United States paid Kuboyama's widow and children the equivalent in yen of about $2,500 ($22,000 in 2016).[17] The tragedy of the Daigo Fukuryū Maru gave rise to a fierce anti-nuclear movement in Japan, rising especially from the fear that the contaminated fish had entered the market. The U.S. government feared this movement would lead to an anti-American movement, and attempted to quickly negotiate a settlement with the Japanese government (led at the time by the Prime Minister Shigeru Yoshida, who was considered to be a pro-U.S. politician). The Japanese and U.S. governments reached a compensation settlement, with the transfer to Japan of a compensation of US $15,300,000,[18] of which it is reported that the fishery received a compensation of US$2 million, with the surviving crew receiving about ¥ 2 million each,[19] ($5,550 in 1954, $48,700 in 2016[20]). It was also agreed that the victims would not be given hibakusha status.[19] The Japanese government also acknowledged that it would not pursue further reparations from the U.S. government.

Medical symptoms and treatment

The majority of medical experts believe that the crew members were infected with hepatitis C through blood transfusions during part of their acute radiation syndrome treatment.[21]

The longest staying crew member spent about a year in hospital following their return to port.[22]

Health history of crew

Like the hibakusha, survivors of atomic bombings in Hiroshima and Nagasaki in 1945, the Lucky Dragon crew were stigmatized because of the Japanese public’s irrational fear of those exposed to radiation (it was commonly believed to be contagious). The crew tried to stay quiet about their exposure for a number of decades, beginning with their discharge from hospital. A number of the crew also had to move away from their previous places of residence to get a fresh start.[22]

Former crew members include the 87-year-old, as of 2014, Susumu Misaki, who opened a tofu shop after the incident.[21]

Twenty years old at the time, Matashichi Oishi, who is reported to have licked the mysterious fallout substance which fell on his ship in March, 1954 as a taste test to ascertain its properties,[8] was 79 years old in August 2013. After the exposure, he left his hometown to open a dry cleaning business. Beginning in the 1980s, he frequently gave talks advocating nuclear disarmament.[23] In 2011, he published a book titled, "The Day the Sun Rose in the West: The Lucky Dragon and I."

Radioactivity of the ship post contamination

The ship in its museum in 2007

The Daigo Fukuryū Maru was deemed safe for public viewing and was preserved in 1976. It is now on display in Tokyo at the Tokyo Metropolitan Daigo Fukuryū Maru Exhibition Hall.[24]


The Toho Film Gojira (Godzilla, 1954), was inspired in part by this event.

A poem Japon Balıkçısı ( The Japanese Fishermen ) was written in 1956 by Turkish poet Nâzım Hikmet Ran about the events.[25]

Ralph Lapp wrote The Voyage of the Lucky Dragon which was published in 1958.[26][27] It was reviewed on the front page of The New York Times Book Review.[28]

A film version of the events, Daigo Fukuryū Maru (1959), was directed and screenwritten by Kaneto Shindo, and produced by Kindai Eiga Kyokai and Shin Seiki Eiga.

See also

Nuclear disasters involving Japan

Notes and references

  1. ^ a b c d e f "Lucky Dragon No. 5 special exhibit". 
  2. ^ Structure shielding against fallout gamma rays from nuclear detonations By Lewis Van Clief Spencer, Arthur B. Chilton, Charles Eisenhauer, Center for Radiation Research, United States. National Bureau of Standards, University of Illinois at Urbana-Champaign. pg 6
  3. ^ Nasaizumi, Research in the effects and influences of the nuclear bomb test explosions, Volume 2 Japan. Committee for Compilation of Report on Research in the Effects of Radioactivity, Japan Society for the Promotion of Science, 1956 - History - page 1281 onwards of 1835 pages.
  4. ^ "Only as Dust in the Face of the Wind": An Analysis of the BRAVO Nuclear Incident in the Pacific, 1954 Martha Smith-Norris The Journal of American-East Asian Relations Vol. 6, No. 1 (SPRING 1997), pp. 1-34". 
  5. ^ http://www.nuclearweaponarchive.org/Usa/Tests/Castle.html
  6. ^ a b  
  7. ^ Leonard Engel,"Twenty-Three Fishermen and a Bomb; The Voyage of the Lucky Dragon", New York Times", February 23, 1958, p. BR1.
  8. ^ a b Hoffman, Michael, "Forgotten atrocity of the atomic age", Japan Times, August 28, 2011, p. 11.
  9. ^ "The Japan Times". March 1, 2009. Retrieved March 23, 2010. 
  10. ^ Kyodo News, "Scientist immediately sought details from U.S. on 1954 Bikini H-bomb test", Japan Times, January 11, 2012, p. 2. Nishiwaki's letter, as of January 2012, was on display at the National Atomic Testing Museum in Nevada.
  11. ^ Altered states: the United States and Japan since the occupation By Michael Schaller, Oxford University Press US, 1997 ISBN 0-19-506916-1.
  12. ^ Chasing Loose Nukes. By Derek Duke
  13. ^ https://www.princeton.edu/sgs/publications/sgs/pdf/2_4DeGeer.pdf The Radioactive Signature of the Hydrogen Bomb.
  14. ^ Joseph Rotblat: visionary for peace. By Reiner Braun, Wiley-VCH, 2007 ISBN 3-527-40690-5
  15. ^ Schreiber, Mark, "Lucky Dragon's lethal catch", Japan Times, March 18, 2012, p. 7.
  16. ^ Bombs in the backyard: atomic testing and American politics By A. Costandina Titus, University of Nevada Press, 2001 ISBN 0-87417-370-1.
  17. ^ Clarfield & Wiecek 1984, p. 207
  18. ^ http://web.archive.org/web/20110719155737/http://www.brookings.edu/projects/archive/nucweapons/50.aspx 50 Facts About U.S. Nuclear Weapons. Atomic Audit: The Costs and Consequences of U.S. Nuclear Weapons Since 1940. Brookings Institution. "Money paid by the State Department to Japan following fallout from the 1954 "Bravo" test: $15,300,000"
  19. ^ a b Keiji Hirano (February 29, 2004). "Bikini Atoll H-bomb damaged fisheries, created prejudice". chugoku. Retrieved November 30, 2008. 
  20. ^ In April 25, 1949 the US dollar was pegged to the YEN at $USD 1 = 360 YEN
  21. ^ a b "As I See It: Gov't must delve deeper into radiation exposure from Bikini Atoll incident". 
  22. ^ a b "Japan nuclear victims in 1950s ‘guinea pigs’ and 'Communists' 12 Jul 2011. Citing Dr Aya Homei ‘Nuclear Japan and the Effects of Radiation, 1945-1960’ journal, Historical Studies in the Natural Sciences.". 
  23. ^ "Victim of Bikini Atoll H-bomb fallout keeps the faith". 
  24. ^ 都立 第五福竜丸展示館 Official Site
  25. ^ http://www.siir.gen.tr/siir/n/nazim_hikmet/the_japanese_fisherman.htm
  26. ^ Google books
  27. ^ Amazon
  28. ^ Leonard Engel,"Twenty-Three Fishermen and a Bomb; The Voyage of the Lucky Dragon", New York Times", February 23, 1958, p. BR1.

Further reading

  • Oishi, Matashichi (2011). The Day the Sun Rose in the West: The Lucky Dragon, and I. University of Hawaii Press. 
  • Clarfield, Gerard H.; Wiecek, William M. (1984). Nuclear America: military and civilian nuclear power in the United States, 1940-1980 (1984 ed.). - Total pages: 518  
  • United States. Congress. Joint Committee on Atomic Energy, U.S. Atomic Energy Commission (1967). Hearings and reports on atomic energy, Volume 20 Hearings and Reports on Atomic Energy, United States. Congress. Joint Committee on Atomic Energy. Compiled by Melvin Price, Publisher U.S. G.P.O., 1957, Original from University of Chicago, Digitized Dec 16, 2010. 

External links

  • Official website of the Tokyo Metropolitan Daigo Fukuryū Maru Exhibition Hall (Japanese)
  • Daigo Fukuryū Maru Exhibit at the Official Homepage of the Hiroshima Peace Memorial Museum Archived here
  • Daigo Fukuryū Maru at the Internet Movie Database