WITNESSarchive

W–020 · Documentary photograph and sources

Plutonium for Fat Man

In the summer of 1945, atomic bombs were being assembled on Tinian for attacks on Japanese cities. Among the Project Alberta specialists was twenty-four-year-old Harold Agnew. Weapons developed at Los Alamos were now being prepared for combat missions.

1. A container on Tinian

Physicist Harold Agnew stands outside a hut on Tinian holding a container that held plutonium for the Fat Man bomb. The plutonium itself is not visible.
Physicist Harold Agnew stands outside a hut on Tinian holding a container that held plutonium for the Fat Man bomb. The plutonium itself is not visible.
Provenance and sources for frame 1

The photographer is unidentified; the catalogue describes a US government serviceman. The image comes from Harold Agnew’s private collection via Los Alamos National Laboratory. Tinian, 1945; the exact day is not recorded. Wikimedia Commons carries the complete frame and identifies it as a US federal-government work in the public domain in the United States. Displayed file: 1486 × 1071 pixels. The source record discusses public-domain status; check which jurisdiction it covers. Full image record in Russian.

commons.wikimedia.orgcdn.lanl.govgao.govahf.nuclearmuseum.orgpeace-nagasaki.go.jpView image file

A photograph from that period shows Agnew outside a hut, holding a small metal container. It is often described as the core of Fat Man. Los Alamos National Laboratory is more precise: the container held plutonium for the bomb; the material itself is not visible. According to a US Government Accountability Office report, Fat Man’s plutonium component contained just over six kilograms of plutonium. The photograph’s exact date is unknown.

On 6 August, Agnew flew towards Hiroshima aboard The Great Artiste. As a scientific observer, he was to measure the blast wave; he also filmed the aftermath. Agnew did not take part in the Nagasaki mission.

Three days later, on 9 August 1945, Fat Man, assembled on Tinian, was aboard the B-29 Bockscar. The aircraft was bound for Kokura, but cloud and smoke forced the crew to turn to its secondary target, Nagasaki. The bomb exploded above the city at 11:02 a.m. local time.

By the end of 1945, approximately 74,000 people had died in Nagasaki and 75,000 had been injured, according to the Nagasaki National Peace Memorial Hall. Those figures end with that year; deaths from the later effects of the bombing are not included.

After the war, Agnew returned to Los Alamos and continued working on nuclear weapons. In 1970, he became director of the laboratory he had first joined as a young physicist.