The Manhattan Project

Oral Histories

Gerhart Friedlander's Interview

German-American chemist Gerhart Friedlander fled Nazi persecution in 1936. He studied at the University of California with Glenn Seaborg, earning his Ph.D. in nuclear chemistry in 1942. The following year, he joined the Manhattan Project at Los Alamos and became group leader of the radioactive lanthanum group in the Chemistry Division. After World War II, Friedlander worked at Brookhaven National Laboratory for many years and chaired the Chemistry Department. In this interview, he describes how Seaborg secretly involved him in plutonium work and how his group investigated the implosion method for the plutonium bomb. He also recalls winning a bet with Enrico Fermi.

Ernest Tremmel's Interview

Ernest Tremmel was a civil engineer who worked on the Manhattan Project for the Army Corps of Engineers, as a purchasing officer. He went on to work for the Atomic Energy Commission (AEC) for many years and as a nuclear energy consultant. In this interview, Tremmel discusses the secrecy of the Manhattan Project and how he learned the goal of the project. He recalls interacting with General Leslie R. Groves, Admiral Hyman Rickover, and other AEC commissioners as well as directors of energy companies. Tremmel explains what made this period, and the quest to build nuclear reactors, so exciting. He also remembers witnessing a nuclear bomb test after the war.

Nancy Greenewalt Frederick's Interview (2006)

Nancy Greenewalt Frederick is the oldest child of Crawford Greenewalt, a chemical engineer for the DuPont Company. He was assigned to act as a liaison between the physicists at the Chicago Met Lab and the engineers at Hanford, who were constructing the B Reactor. He went on to become the President of DuPont, and was renowned for his interest in photography, birds, and other scientific endeavors. Frederick discusses her father’s wide-ranging interests, his passion for his job, and the activities he enjoyed pursuing with his wife, family, and friends.

Clarence Larson's Interview

Dr. Clarence Larson, a chemist, began working under Ernest O. Lawrence in his lab at the University of California, Berkeley in 1942. In 1943, he moved to Oak Ridge and was appointed head of technical staff for the Tennessee Eastman Corporation. He later served as director of Oak Ridge National Laboratory and as a commissioner on the U.S. Atomic Energy Commission. During the Manhattan Project, Larson designed a process to recover and purify uranium deposits from the walls of calutron receivers at the Y-12 Plant. In this interview, he explains the importance of this innovation in producing enough enriched uranium for an atomic bomb. He also describes the challenges encountered in the Y-12 Plant’s early days, as well as Lawrence’s leadership skills and unyielding confidence.

James C. Hobbs's Interview - Part 3

J.C. Hobbs was an American inventor and engineer who created a key part of the valves used in the K-25 gaseous diffusion plant in Oak Ridge, Tennessee. Hobbs was brought on to the Manhattan Project by the head of the Kellex Corporation, Percival Keith, to improve the piping system in the K-25 plant. In part three of his interview with Stephane Groueff, Hobbs discusses the key role he played in troubleshooting problems for K-25 and for other power plants across the country. He emphasizes the importance of the efficiencies he introduced at K-25, and describes some of the technical challenges he and his colleagues faced.

Hans Bethe's Interview (1982) - Part 2

Hans Bethe was a German-American physicist and Nobel Prize winner who was head of the Theoretical Division at Los Alamos. He played an important role in the development of the hydrogen fusion bomb. In this interview, Bethe explains why he opposed developing the hydrogen bomb and provides insight into the General Advisory Committee’s decision to pursue it. He also discusses nuclear proliferation, which scientists may have influenced J. Robert Oppenheimer’s thoughts on the hydrogen bomb, and the challenges of developing the H-bomb.

Harry Allen and Robert Van Gemert's Interview

Harry Allen and Robert Van Gemert worked in procurement at Los Alamos during the Manhattan Project. In this interview, the pair discusses getting ready for the Trinity test, the challenges of using Jumbo, and how materials were transported safely and secretly in and out of Los Alamos. They remember helping to acquire the lead-lined tanks used to transport scientists to the blast zone after the Trinity test. Allen and Van Gemert also discuss the dormitories at Los Alamos, how the Town Council handled problems, and the secrets of PO Box 1663. They recall their interactions with leading scientists including Emilio Segre, Enrico Fermi, and Edward Teller.

Norris Bradbury's Interview - Part 1

Norris Bradbury was an American physicist and director of the Los Alamos National Laboratory from 1945-1970. During the Manhattan Project, Bradbury directed the implosion field test program and helped prepare the “Gadget” for the Trinity test. In this interview, Bradbury explains why he was selected to work at Los Alamos, and discusses his work on the plutonium implosion bomb. He recalls his interactions with Manhattan Project leaders J. Robert Oppenheimer, George Kistiakowsky, and Admiral Deak Parsons. Bradbury watched over the “Gadget” at the top of the Trinity test tower to ensure that no one “monkeyed” around with it. He remembers his surprise when Oppenheimer picked him to take over as director of the laboratory, and the challenges he had to overcome to keep the lab up and running.

General Kenneth Nichols's Interview - Part 3

General Kenneth Nichols was the District Engineer for the Manhattan Engineering District, and oversaw the design and operation of the Hanford and Oak Ridge sites. He was responsible for securing the initial deals with Stone & Webster and the DuPont Company to develop the industry for the site, and lived for a time with his wife at Oak Ridge. He discusses sabotage and Klaus Fuchs, dealings with the British, and the very start of the Manhattan Project. He recalls some conflict between the scientists and engineers, the importance of industry in the project, and the initial problems with the startup of the B Reactor.

General Paul Tibbets – Reflections on Hiroshima

Colonel (later General) Paul Tibbets was the pilot of the Enola Gay, the B-29 that dropped the “Little Boy” atomic bomb over Hiroshima on August 6, 1945. In this documentary Tibbets co-produced with the Buckeye Aviation Book Company, “Reflections on Hiroshima,” he recounts his memories of the day the atomic bomb was first used in warfare. Tibbets recalls how he became a pilot, and explains how the Manhattan Project’s “Silverplate” program produced a special version of the B-29 capable of delivering the atomic bomb. He also discusses the target selection process and describes the “odd couple” of J. Robert Oppenheimer and General Leslie Groves. He remembers seeing the mushroom cloud over Hiroshima and feeling the shock wave of the blast, and shares his views on the role of morality during war.