AIP History Center Newsletter
Volume XXX, No. 1, Spring 1998


Crawford Greenewalt's Manhattan Project Diary

by Michael Nash (Chief Curator, Library Collections, Hagley Museum and Library)

A diary kept by Crawford Greenewalt provides a remarkable example of how science and technology may be documented for posterity. It provides unique insights into the Manhattan Project to develop the atomic bomb, one of the most important and dramatic chapters in the history of modern physics and technology. General Leslie Groves, who was overseeing the project for the War Department, recognized that engineering capability would be essential if the theoretical work being done at the University of Chicago was to be transformed into a production system capable of manufacturing sufficient plutonium for several atomic bombs. In the fall of 1942 he asked the DuPont Company to serve as a subcontractor for a plutonium separation plant, and in December DuPont signed a contract to design and build a facility which turned out to be the Hanford Engineering Works (in Washington state). Crawford Greenewalt, who had managed DuPont's nylon project before the war, served as liaison between the University of Chicago physicists and the DuPont engineers.

Greenwalt's strength was his experience in transforming "pure research" into a full-scale production project. He conveyed the DuPont design team's needs for research data to the physicists in Chicago and presented the engineering work to them for their review. He and the DuPont engineers stressed safety and margin-of-error, which anticipated differences in theory and practice that were essential if the Chicago scientist's theoretical and experimental physics were to be translated into engineering achievement. By 1945, overcoming countless obstacles, the Hanford Engineering Works furnished the Los Alamos National Laboratory with sufficient plutonium to assemble the bombs tested at Alamogordo, New Mexico and detonated over Nagasaki.

Throughout Greenewalt kept a detailed diary describing the project and his relationship, at times uneasy, with the University of Chicago physicists. The seven volumes document the drama surrounding the development of the atomic bomb and the excitement of those who witnessed the first chain reaction. The Greenewalt diary contains a good deal of technical information describing the problems in theoretical physics that had to be solved in order to develop the atomic bomb. It also documents how the work of the University of Chicago physicists was influenced by engineering imperatives . The diary, which contains copies of Greenewalt's correspondence with the scientists at the University of Chicago, depicts some of the classic tensions between "science" and "engineering."

In 1990 the Crawford Greenewalt's Manhattan Project Diary was deposited with the Hagley Museum and Library, an independent research library in Wilmington, Delaware that is the repository for the records of the DuPont Company. In its declassified form it is available for research. David Hounshell of Carnegie Mellon University in Pittsburgh is in the process of editing the diary for publication by American Philosophical Society Press.

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