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National Museum of Nuclear Science & History

In Memoriam: Ted Petry

Ted Petry at the U of Chicago Monument to the Chicago Pile-1 scientists. Courtesy of Joseph Dowling.

Manhattan Project veteran Ted Petry passed away on July 28, according to the University of Chicago. Petry was 94. He was the last known living witness to Chicago Pile-1, the first controlled, self-sustained nuclear chain reaction.

AHF was fortunate to be able to interview Petry earlier this year. You can watch the interview on the Voices of the Manhattan Project website.

Petry was born on June 21, 1924, and grew up on the South Side of Chicago. He attended Tilden Technical High School, and after graduating, joined the University of Chicago’s Metallurgical Laboratory as a messenger and laboratory helper.

Some of Petry’s tasks involved handling radioactive materials. He recalled that radiation protection measures were primitive. “I would go downtown and pick up uranium or some radioactive material, actually just put it in my pocket, and go back with it to the university,” he described. But after a blood test indicated he had been overexposed to radiation, he remembered, the project changed its policy to “picking up the radioactive material with a station wagon and a lead container, where they could put the radioactive material in it and bring it back to the university.”

Petry handled graphite and helped plane carbon blocks for Chicago Pile-1 (CP-1), which workers and scientists built under the West Stands of Stagg Field on the University of Chicago campus. He remembered the assembly of CP-1: “There were stairs that went down to the bottom of the tower. We put a 2×12 on one side of the stairs, and we could slide the carbon blocks down. Eventually, it got very slippery and they really whizzed down there. We would have like a mattress down at the bottom where they would land. Then we could pile them up. I understand there were 45,000 blocks in the pile. Wow. I didn’t believe that we worked with that many!”

After his time at the Met Lab, Petry spent a brief time as a deckhand on an ore freighter on Lake Michigan. He worked at the Pullman Company and as an electrician for the Joslyn Manufacturing Company before becoming a shop teacher.

Petry was modest about his role in CP-1. “It was so secret at that time. It was just a job,” he stated. He met President John F. Kennedy in 1962 at a White House ceremony commemorating the 20th anniversary of the event, and was recognized at the University of Chicago’s commemoration of the 75th anniversary of CP-1 in 2017. He was also profiled by the Chicago Tribune and Washington Post.

For more about Petry and his involvement in the Manhattan Project, see this University of Chicago article. To watch Petry’s oral history interview, click here.