page_title: Dayton Project
section_title: Locations
hierarchical_section_title: Dayton Project / Locations
caption_attribution_description: English: Dayton Project - Unit IV in October 1947
context_page_description: The Dayton Project was a research and development project to produce polonium during World War II, as part of the larger Manhattan Project to build the first atomic bombs. Work took place at several sites in and around Dayton, Ohio. Those working on the project were ultimately responsible for creating the polonium-based modulated neutron initiators which were used to begin the chain reactions in the atomic bombs.
  The Dayton Project began in 1943 when Monsanto's Charles Allen Thomas was recruited by the Manhattan Project to coordinate the plutonium purification and production work being carried out at various sites. Scientists at the Los Alamos Laboratory calculated that a plutonium bomb would require a neutron initiator. The best-known neutron sources used radioactive polonium and beryllium, so Thomas undertook to produce polonium at Monsanto's laboratories in Dayton. While most Manhattan Project activity took place at remote locations, the Dayton Project was located in a populated, urban area. It ran from 1943 to 1949, when the Mound Laboratories were completed in nearby Miamisburg, Ohio, and the work moved there.
context_section_description: Office space was initially found in the Monsanto offices at 1515 Nicholas Rd, which became known as Unit I. Unit II was the Monsanto Rocket Propellant works off Betty Lane near Ohio State Route 741. While it was administered by Monsanto, it was not used by the Dayton Project. The site handled explosives including ammonium nitrate and ammonium picrate, but no radioactive materials were handled there. Work at Unit II ceased in the fall of 1945. Consideration was given to using it in December 1946, but this proposal was rejected in favor of erecting a Quonset hut at Unit III.
  A laboratory site was found at 1601 W. First Street that had originally been constructed to house the Bonebrake Seminary. It was a three-story brick building built in 1879, and owned by the Dayton Board of Education, which used it as a warehouse. Monsanto leased the site on 15 October 1943, and began converting it into a laboratory known as Unit III. The building was in poor shape when the Dayton Project took it over, with many broken windows, and the staircase between the second and third floors was missing. New heating and lighting were installed, windows were replaced, new flooring was laid, and some rooms were re-plastered. A pair of guard houses known as buildings J and K were added, as was a chemical storage shed known as building F, and a wire fence. Laboratory activities were transferred there from Unit I on 25 September. Initially only the bottom two floors were occupied, providing 560 square meters (6,000 sq ft) of laboratory space. Later, the third floor was taken over as well, providing another  280 square meters (3,000 sq ft). In May 1945, five additional temporary buildings were constructed on land leased from the Board of Education that housed offices, a cafeteria, locker rooms, a physics laboratory and a laundry. A new guardhouse was also built. To this was added two portable buildings in 1946.
  By 1944, space was running short, and Monsanto began negotiations to acquire the Runnymede Playhouse in the wealthy residential Dayton suburb of Oakwood. Built in 1927, the Playhouse was a leisure facility that included an outdoor swimming pool, a ballroom, a squash court, a tennis court with a cork floor and a stage for community theater. It had showers with Italian marble and a ​1 ¹⁄₂-story garage. The estate was owned by the Talbott Realty Company, which was controlled by Thomas's wife's family. The Talbotts were among the heirs of the Delco company, which was by then a part of General Motors. The Oakwood City Council wanted the Playhouse as a community center. Thomas appeared before the council and assured them that it would not be damaged, although he could not disclose what he was intending to use it for. When Talbott Realty proved reluctant to sell, the United States Army Corps of Engineers condemned the property, which became Unit IV on 15 February 1944. A lease was signed on 10 March 1944, under which the Talbott Realty was paid $4,266.72 per annum for the property. The lease was initially up to 30 June 1944, but was then extended annually until 30 June 1949. The lease specified that the property would be returned in its original condition. Talbott Realty were told that the property would be used to produce training films.
  Remodeling began on 17 March 1944. The tennis courts were subdivided into multiple rooms. The ceiling was lowered, and heating, air conditioning and air filtration systems were added. One of the greenhouses was converted into a loading dock. The property was enclosed in a barbed wire fence that was floodlit by night, and patrolled around the clock by armed guards; there were 43 guards at Units III and IV. The Production Group began moving in on 1 June. Three guard houses were added, along with a wire fence. Changes to the site were minimized in order to make it easier to restore later. Because it was located in a residential area, efforts were also made to minimize noise and other disruptions.
  In May 1945, Monsanto rented three floors of a warehouse at 601 East Third Street from General Electric. Initially it was used 
caption: Dayton Project – Unit IV in October 1947
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