Contra Costa County, California. Constructed 30 miles NE of San Francisco, California, on Suisun Bay; authorized December 9, 1941 by Secretary of the Navy Frank Knox. Ammunition loading aboard civilian deep water transports destined for the Pacific Theater of war commenced November 1942.
The Navy facility was identified by the nearest United States post office and thus designated Port Chicago by reference to the small rural town that lay one and one-half miles inland from the southern shore of Suisun Bay at the base of a range of low hills south of the town. Beyond the hills lay a fertile expanse of small and picturesquely lovely small California farms and orchards that since World War II have been entirely transformed to accommodate the present population of one million, of whom 120,000 live in the city of Concord.
The Port Chicago magazine was served by the Santa Fe, Southern Pacific and Western Pacific rail roads by which the flow of wartime munitions to the magazine could easily move from manufacturing plants across the country and, for example, from the remote and very much larger Navy munitions depot at Hawthorne, Nevada.
Ship loading operations at the facility pier were conducted by 1,000 African-American enlisted Navy personnel in 24-hour operations. The explosion of the fully laden Liberty ship E. A. Bryan at the magazine pier at 10:30 the evening of 17 July 1944 resulted in the immediate death of 320 men on and about the exploded ship and the injury of several hundred-sailors on the base and civilians in the surrounding territory. Destruction and damage at the base facilities was extensive, but the base was rapidly reconstructed and returned to service.
Fissionable and hardware components of the atomic bomb detonated in combat 6 August 1945 at Hiroshima, Japan, were transshipped through the Port Chicago base late in July 1945. The base has since continuously been a munitions transshipment facility operated by the Navy with contributions to the conduct of the Korean and Vietnamese wars and was the site of contentious antiwar protests and antinuclear demonstrations during the 1960s, 70s and 80s. The base since World War II has been the principal West coast transshipment, storage and repair facility for the Navy's nuclear weapons, but the site was recently transferred to the U.S. Army.
In consideration of the casualties
of the 1944 explosion, the important role of the base during World War
II and the national historical importance of the explosion, the Port Chicago
Naval Magazine National Memorial was established by Congressional enactment
(Public Law 102-562; 102d Congress) 28 October 1992 and signed into law
by President George Bush. The National Memorial was dedicated by the National
Park Service on the 50th anniversary of the explosion 17 July 1994.
In the aftermath of the explosion
300 uninjured African-American enlisted Navy men on the base en masse
refused to comply when ordered to return to their assigned duty loading
ammunition into the cargo holds of ships destined for the Pacific Theater
of war. Although the Port Chicago Magazine shiploading pier had been destroyed
in the explosion, the nearby Mare Island Naval Magazine piers were operational;
to that facility the men were ordered to duty, which order they refused.
Following confinement below decks on a barge at Mare Island the assembled
men were addressed by the Commandant of the 12 Naval District (San Francisco)
and instructed that they were subject to summary execution if they remained
in defiance. Two hundred seventy-five men then agreed to return to duty
as ordered and in summary courts-martial were convicted of insubordination
and other offenses. Fifty of the men remained obdurate and were charged
with mutiny-in-wartime and convicted of that charge by formal Navy court-martial.
The Port Chicago mutiny is the largest mutiny in United States military
history. Various legal reviews of the proceedings during 55 years sustained
the convictions. On December 23, 1999, President William Clinton granted
presidential pardon to one of the two known surviving Port Chicago mutineers,
Mr. Freddie Meeks.
one of two or more atoms of
an atomic element, the nuclei of which have the same number of protons
but differ in the number of neutrons; the variation of neutron number
among the nuclei of isotopes of the same element distinguish each isotope
by a different atomic mass. In chemical reactions, all isotopes of the
same element behave identically.
heavy silvery-white metallic
element, radioactive, easily oxidized; atomic number 92, atomic weight
238.03, melting point 1,132?C, boiling point 3,818?C. Named in reference
to the planet Uranus, and having 14 known isotopes of which U238 is the
most abundant in nature. The peculiar nuclear properties of the U238 isotope
determined that a fission chain reaction in U238 was, for practical purposes,
unrealizable during World War II. In the isotope U235, however, conditions
are favorable to a divergent nuclear fission chain reaction.
uranium isotope with mass number
235 and half-life 7.13 X 108 years, fissionable with slow "thermal"
energy neutrons and capable in a supercritical mass of sustaining a nuclear
fission chain reaction that can proceed explosively with appropriate mechanical
natural uranium modified by
isotope separation (concentration) to increase the 0.7% occurrence of
the U235 isotope to 93%; highly enriched uranium was employed as the fissionable
material for the Mark I weapon detonated in combat at Hiroshima; highly
enriched uranium contrasts with the slightly enriched uranium (approximately
20% U235) employed in the Mark II weapon which was proof fired at the
Port Chicago Naval Magazine 17 July 1944.
isolation of one isotope from
an element in which it naturally occurs, or concentration of one isotope
by the removal of unwanted isotopes from an element in which they occur.
Since isotopes of the same element behave identically in chemical reactions,
World War II separation of uranium isotopes was accomplished by mechanical
methods, which depended on the different atomic weight of each isotope
as determined by the number of neutrons in the nucleus of each isotope.
the isotopes of natural uranium prepared in liquid and heated in a vertical column will separate by the ensuing rise, or diffusion, of the lighter isotopes to the top of the column and the settling of the heavier isotopes to the bottom; in this system the lighter, fissionable U235 isotope accumulates at the top of the column and the heavier, non-fissionable U238 isotope accumulates at the bottom.
Many such columns connected
in series as a cascade process the partially U235 separated material drawn
from the top of each preceding column to the next, so that the separation
and accumulation of U235 is gradually increased in each column as the
liquid material passes through the cascade. The process was developed
by Philip Abelson, first at the United States Naval Research Laboratory
and during the first six months of 1943 had produced the first separated
U235 in weapon quantity.
nuclear reaction in which an atomic nucleus is split into fragments, usually
two fragments of comparable mass, by the impingement of an energetic free
moving neutron, with the release of one or more neutrons from the split
nucleus, which may sustain or multiply the fission process in U235 or
plutonium; the fission of each nucleus evolves 100 million to several
hundred million electron volts of energy.
highly U235 enriched uranium
gun assembly atomic bomb detonated in combat at Hiroshima, Japan, 6 August
1945, but not proof fired with active material prior to combat use; also
known as Little Boy.
autocatalytic uranium hydride
lateral implosion experimental device; previously undisclosed Manhattan
Project cylindrical configuration U235 or plutonium atomic bomb design
and technology which was precursor to Mark III; Mark II, a low-yield,
tactical weapon, was certified 4 July 1944 to the Joint Chiefs of Staff
for the purposes of operational planning, subject to the necessity of
one proof firing before the Mark II could be available for combat use.
The Port Chicago explosion which provided proof of the Mark II weapon
determined the future development of Mark II; in consequence of the Port
Chicago explosion Mark II was put on the shelf 17 August 1944, with agreement
that the Mark II could be developed for combat use in 3 or 4 months time
if required. Chief of Staff Gen. George C. Marshall planned the use of
nine Mark II weapons, each with an anticipated energy yield equivalent
to 1,000 tons of TNT, to prepare Japanese beaches and near-shore areas
for an Allied invasion of the Japanese home islands if that invasion had
been required. Two postwar experimental detonations of Mark II were conducted
at the Nevada test site: Ruth and Ray of the 1953 Upshot-Knothole series.
first prototype spherical implosion
atomic bomb design and technology susceptible to use with highly U235
enriched uranium or plutonium; did not use focused implosion technology;
not proof fired with active material, and eliminated from practical development
by assurance the markedly more efficient Mark IV bomb design would be
improved the efficiency of
the prototype Mark III spherical implosion design by application of focused
implosion technology; susceptible to use with highly U235 enriched uranium
or plutonium; with plutonium was proof fired at Trinity site, New Mexico,
16 July 1945 and detonated with plutonium in combat at Nagasaki, Japan,
9 August 1945; also known as Fat Man.
(Three members; one alternate.)
Washington, DC, Carnegie Institution President Vannevar Bush, civilian
committee member and committee chairman (deceased); Harvard University
President James B. Conant, alternate civilian committee member and alternate
committee chairman (deceased); Rear Admiral William R. Purnell, USN, Navy
member (deceased); and General Wilhelm D. Styer, USA, Army member (deceased).
President Franklin D. Roosevelt had designated Vice President Henry A.
Wallace, Secretary of War Henry L. Stimson and Army Chief of Staff General
George C. Marshall to have determination of general policy in the atomic
bomb project who, on September 23, 1942, appointed the Military Policy
Committee, and appointed General Leslie R. Groves the committee's executive
officer. Constituted as above, the committee served through World War
Rear Admiral William Sterling, USN:
Chief Scientist Emeritus Laboratory
for Cosmic Physics, United States Naval Research Laboratory; civilian
Manhattan Project scientist at Los Alamos Laboratories who, with Capt.
Parsons and Ens. Reynolds, conducted extensive onsite investigations of
the physical effects of the Port Chicago explosion in the immediate aftermath,
which were reported in several hundred pages of analysis transmitted by
Capt. Parsons to Military Policy Committee member Adm. William R. Purnell
between July 27, 1944 and October 1944 (surviving).
career associate, friend and
confidant of Capt. Parsons; assigned duty at Los Alamos Laboratories,
autumn 1944, on recommendation of Adm. Purnell and Capt. Parsons, to whom
then-Commander Ashworth reported; bomb commander Nagasaki mission, 9 August
1945; participated in postwar Bikini and Eniwitok atomic bomb tests as
Adm. Parsons' executive officer; retired commander United States Navy
6th Fleet (surviving).
document purloined, winter
1944-45, from the Manhattan Project Los Alamos Laboratories by photo technician
Paul Masters; mathematical model prediction of the progression and effects
of the explosion of the Mark IV weapon detonated 16 July 1945 at New Mexico
Trinity site; prepared by Los Alamos scientists Joseph O. Hirschfelder
and William G. Penney. Provides detailed technical specifications of Mark
IV and, in the bottom line, predicts "Ball of fire mushroom out at
18,000' in typical Port Chicago fashion." Document recovered by the
author among 1940s photo supplies donated by Paul Masters to the spring
1980 rummage sale of the Christ Evangelical Lutheran church, Santa Fe,
New Mexico; published by the author, spring 1982.