page_title: McDonald Ranch House
section_title: Manhattan Project
hierarchical_section_title: McDonald Ranch House / Manhattan Project
caption_attribution_description: TRINITY PHOTOGRAPH - Alamogordo, NM - Trinity Test, July 16, 1945 - Vital Components are loaded at the old McDonald Ranch for the trip to the Trinity test site.
context_page_description: The McDonald Ranch House, also known as Trinity Site, in the Oscura Mountains of Socorro County, New Mexico, was the location of assembly of the world's first nuclear weapon. The active components of the Trinity test "gadget", a plutonium Fat Man-type bomb similar to that later dropped on Nagasaki, Japan, were assembled there on July 13, 1945. The completed bomb was winched up the test tower the following day and detonated on July 16, 1945 as the Trinity nuclear test.
  The McDonald Ranch House was built in 1913 by Franz Schmidt, a German immigrant, and acquired by the McDonald family in the 1930s. The ranch was vacated by the McDonald family under protest in 1942, when the United States Army took over the land as part of the Alamogordo Bombing and Gunnery Range to use in training bomber crews during World War II.
  The family hoped that the ranch would be returned after the war, but it was not, and in 1970, the Army announced that it would be kept permanently. The McDonald Ranch House was empty and deteriorating until 1982, when it was stabilized by the Army. In 1984 it was restored by the National Park Service to appear as it did on July 12, 1945.
context_section_description: The house stood empty until the Manhattan Project support personnel arrived in early 1945. The northeast room (the master bedroom) was designated the assembly room. Workbenches and tables were installed. To keep dust and sand out of instruments and tools, the windows were covered with plastic. Tape was used to fasten the edges of the plastic and to seal doors and cracks in the walls.
  The plutonium hemispheres for the pit of the Trinity nuclear test "gadget" (bomb) were delivered to the McDonald Ranch House on July 11, 1945. Brigadier General Thomas F. Farrell, the Deputy Director of the Manhattan Project, signed for them, and handed them over to Louis Slotin, the head of the Pit Assembly Team. The active components of the bomb were assembled in the assembly room on July 13, 1945, The bomb was winched up the test tower the following day. The Trinity test occurred on July 16, 1945. A plutonium Fat Man-type bomb was detonated, similar to the bomb later dropped on Nagasaki.
  The explosion only 2 miles (3.2 km) away blew most of the home's windows out but did not significantly damage the structure; years of rain water intrusion through the roof were responsible for decades of subsequent deterioration. The barn roof was bowed inward by the blast and some of its roofing was blown away; it collapsed some time thereafter.
caption: Vital Components are loaded at the old McDonald Ranch for the trip to the test site
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