Bikini Atoll - Baker Test - Exp. #2 -July 25, 1946

Bikini Atoll - Baker Test - Blast column ascending - Official Photo - 25 July 1946
This is an official, sepia tone, U.S. government photo designated: "DBCR-TI-318-EXP # 2 Bikini Atoll" & "AF 434 - 6". It depicts the first underwater nuclear explosion of an Mk 3A atomic bomb, the same as the "Fat Man" bomb detonated over Nagasaki, Japan on 9 August 1945. On Baker Day of Operation Crossroads, the bomb was detonated underwater at the Bikini Atoll, in the Marshall Islands on 25 July 1945. This iconic image is one of the most famous of the "Atomic Age" and was selected by Wikipedia as the "Picture of the Day" for 25 July 2009, indicating that as a Wikipedia Featured Picture the image is deemed to be one of the finest of the entire English Language Wikipedia.

This photograph of the Baker Test was taken approximately 10 seconds after detonation. Taken from a tower on Enyu Island in the Bikini Atoll, it was about 3.5 miles away from the explosion. The photograph captured both the enormous column of water thrust into the atmosphere and the temporary condensation cloud, called a Wilson Cloud, created by the blast. The blast displaced 2,000,000 tons of water and 2,000,000 cubic yards of sediment into a hollow, radioactive geyser that rose 10,000 feet into the atmosphere, was 2000 feet across and the outer walls of which were 300 feet thick.

The detonation has been likened to resembling a giant cauliflower of water, the base forming the stalk and the top of the geyser resembling the head. It was briefly surrounded in its entirety by a temporary fog, the Wilson Cloud, formed immediately after the explosion by the temperature differential caused by the low pressure zone created behind the advancing blast wave which caused moisture to condense out of the humid tropical air of the South Pacific.

In this image the Wilson Cloud had begun to disperse into a doughnut shape around the geyser. As it evaporated around the base of the "cauliflower" a dark vertical streak can be observed in the lower right side of the base. This is the battleship USS Arkansas (BB-33), a 27,680 ton ship, upended vertically, capsized and sunk by the force of the blast.

Operation Crossroads was undertaken to test the effects of nuclear explosions, both air burst and submerged detonations. Accordingly, vessels representing every type of ship used in WWII were assembled from U.S. vessels and captured enemy ships, many of which may be seen in the photograph. Both explosions were conducted at Bikini Atoll and involved 242 ships, 156 aircraft and over 42,000 military & naval personnel as well as the 162 residents of the atoll who were safely relocated to Rongerik atoll.

The Baker device was a 23 kiloton bomb. It was suspended in about 100 feet of water - in contrast to an earlier 1 July 1946, airburst test, code named "Able". It was conducted under the auspices of the Deputy Chief of Naval Operations for Special Weapons Vice Admiral William H. P. Blandy the Commander of Joint Task Force 1. Rear Admiral William "Deak" Parsons acquired these photographs in his role as the Deputy Commander for Technical Direction and Commander Task Group One.

The Crossroads detonations were the first atomic explosions since the end of WWII and the first "weapons effects" tests ever conducted to determine how nuclear explosions would affect vessels, aircraft, installations, the atmosphere and the oceans.

As "effects" tests were untried there was much speculation in the press of the day about the blasts. These speculations caused Vice Admiral Blandy to issue the following statement prior to the explosions;

"The bomb will not start a chain-reaction in the water converting it all to gas and letting the ships on all the oceans drop down to the bottom.
It will not blow out the bottom of the sea and let all the water run down the hole.
It will not destroy gravity.
I am not an atomic playboy, as one of my critics labeled me, exploding these bombs to satisfy my personal whim

Vice Admiral W.H.P. Blandy, Commander Joint Task Force One, Operation Crossroads"

Today these statements seem almost comical, but they were taken seriously enough in 1946 to compel an official response from a Deputy Chief of Naval Operations.
As the United States entered the "Atomic Age" it is interesting to note the role flags played in Operation Crossroads. Signal flag "Y" was used to signal that a target ship was clear of all personnel. After the detonation the Special Engineering Detachment - Radiological Safety Section - Boarding Party Monitors were tasked with visiting the target ships to access blast damage. They used signal flags to signal the status of a target ship: signal flag Able meant a ship was safe to reboard for further study while signal flag Baker indicated danger and that the ship could not be reboarded.
ZFC3862 was acquired with another Operation Crossroads image (ZFC3863).

Provenance:
* U.S. Army Air Force 25 July 1946.
* Acquired by Rear Admiral William "Deak" Parsons, July 1946.
* Retained by Admiral Parsons until passing 1953.
* Parsons' estate conveyed to USN Procurement officer, until 1991.
* Sold via Frank Cea's Barnstormer Auction, Roosevelt Airfield, Long Island, New York, to The War Museum of New York City, 1991.
* The War Museum of New York city, until 2013.
* Sold via Bonham's of New York City, NY to Zaricor Flag Collection, 2013.

Sources:

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Operation Crossroads - 1946, The Nuclear Weapon Archive, 9 April 2013, from: http://nuclearweaponarchive.org/Usa/Tests/Crossrd.html

Bonhams, Bonhams, World War II: The Pacific Theater, Auction 21082, Lot 177, 9 April 2013, from: http://www.bonhams.com/auctions/21082/lot/177/

25 July 1946 'Test Baker', Bikini Atoll, Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), 9 April 2013, from: http://www.ctbto.org/specials/infamous-anniversaries/25-july-1946test-baker-bikini-atoll/

Fay L. Cunningham Collection, 1 of 2, The Manhattan Project Heritage Preservation Association, Inc., 9 April 2013, from: http://www.mphpa.org/classic/COLLECTIONS/OCP-FCUN/Pages/FCUN_Gallery_01.htm

Fay L. Cunningham Collection, 2 of 2, The Manhattan Project Heritage Preservation Association, Inc., 9 April 2013, from: http://www.mphpa.org/classic/COLLECTIONS/OCP-FCUN/Pages/FCUN_Gallery_02.htm

William Henry Purnell Blandy, Wikipedia, 9 April 12103, from: http://en.wikipedia.org/wiki/William_H._P._Blandy

William Sterling Parsons, Wikipedia, 9 April, from: http://en.wikipedia.org/wiki/William_Sterling_Parsons

William L. Laurence, Wikipedia, 9 April 2012, from: http://en.wikipedia.org/wiki/William_L._Laurence

Operation Crossroads, Wikipedia, Wikipedia, 9 April 12103, from: http://en.wikipedia.org/wiki/Operation_Crossroads

Declassified U.S. Nuclear Test Film #02, You Tube, 9 April 2013, from: http://www.youtube.com/watch?v=8Tjj2pq7FiE

Zaricor Flag Collection (ZFC) Archives, 2013.

Image Credits:
Zaricor Flag Collection
Bonhams




AWSP

Hoist & Fly
Width of Hoist	8
Length of Fly	10

Frame
Is it framed?	no

Nationality
Nation Represented	United States

Fabric
Fabric	Paper

Attachment
Method of Attachment	None

Applica
Applique Sides	3-D Artifact

Documentation
Documents	All original documents and drawings are held in the Zaricor Flag Collection Archives.
Drawings	All original documents and drawings are held in the Zaricor Flag Collection Archives.
Research Documents	All original documents and drawings are held in the Zaricor Flag Collection Archives.
Public Copy & Signs	All original documents and drawings are held in the Zaricor Flag Collection Archives.

Condition
Condition	Good
Damage	Used
Displayable	yes

Date
Date	1946