McDonald Ranch House
Encyclopedia
The McDonald Ranch House was the location of assembly for the first tested nuclear weapon. The test occurred on July 16, 1945; a plutonium
bomb was tested, the type of weapon later dropped on Nagasaki, Japan
. The weapon used against
Hiroshima
was a uranium
bomb, a type not tested prior to its use in World War II
, because it had a simpler design.
The "gadget" was assembled there, the components having arrived on July 12. It was assembled on the next day, and winched up the Trinity test tower the following day.
The George McDonald Ranch House sits within an 85' x 85' low stone wall. The house was built in 1913 by Franz Schmidt, a German immigrant, and an addition was constructed on the north side in the 1930s by the McDonalds. There is a display on the Schmidt family in the house during each open house.
The ranch house is a one-story, 1750 square feet (162.6 m²) building. It is built of adobe, which was plastered and painted. An ice house is located on the west side, along with an underground cistern which stored rain water running off the roof. At one time, the north addition contained a toilet and bathtub, which drained into a septic tank northwest of the house.
There is a large, divided water storage tank and a Chicago Aermotor windmill east of the house. The scientists and support people used the north tank as a swimming pool during the long hot summer of 1945. South of the windmill are the remains of a bunkhouse and a barn which was part garage. Further to the east are corrals and holding pens. The buildings and fixtures east of the house have been stabilized to prevent further deterioration.
The ranch was evacuated under protest in 1942, when the Alamogordo Bombing and Gunnery Range took over the land to use in training World War II bombing crews. The house stood empty until the Manhattan Project support personnel arrived in early 1945.
Inside the house, 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 explosion, only two miles away, did not significantly damage the house. Most of the windows were blown out, but the main structure was intact. Years of rain water dripping through holes in the roof did much more damage. The barn did not do as well. During the Trinity test, the roof was bowed inward and some of the roofing was blown away. The roof has since collapsed.
The house stood empty and deteriorating until 1982, when the U.S. Army stabilized the house to prevent any further damage. Shortly after, the Department of Energy and U.S. Army provided the funds for the National Park Service to completely restore the house. The work was completed in 1984. All efforts were directed at making the house appear as it did on July 12, 1945.
Plutonium
Plutonium is a transuranic radioactive chemical element with the chemical symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, forming a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation...
bomb was tested, the type of weapon later dropped on Nagasaki, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
. The weapon used against
Atomic bombings of Hiroshima and Nagasaki
During the final stages of World War II in 1945, the United States conducted two atomic bombings against the cities of Hiroshima and Nagasaki in Japan, the first on August 6, 1945, and the second on August 9, 1945. These two events are the only use of nuclear weapons in war to date.For six months...
Hiroshima
Hiroshima
is the capital of Hiroshima Prefecture, and the largest city in the Chūgoku region of western Honshu, the largest island of Japan. It became best known as the first city in history to be destroyed by a nuclear weapon when the United States Army Air Forces dropped an atomic bomb on it at 8:15 A.M...
was a uranium
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
bomb, a type not tested prior to its use in World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, because it had a simpler design.
The "gadget" was assembled there, the components having arrived on July 12. It was assembled on the next day, and winched up the Trinity test tower the following day.
The George McDonald Ranch House sits within an 85' x 85' low stone wall. The house was built in 1913 by Franz Schmidt, a German immigrant, and an addition was constructed on the north side in the 1930s by the McDonalds. There is a display on the Schmidt family in the house during each open house.
The ranch house is a one-story, 1750 square feet (162.6 m²) building. It is built of adobe, which was plastered and painted. An ice house is located on the west side, along with an underground cistern which stored rain water running off the roof. At one time, the north addition contained a toilet and bathtub, which drained into a septic tank northwest of the house.
There is a large, divided water storage tank and a Chicago Aermotor windmill east of the house. The scientists and support people used the north tank as a swimming pool during the long hot summer of 1945. South of the windmill are the remains of a bunkhouse and a barn which was part garage. Further to the east are corrals and holding pens. The buildings and fixtures east of the house have been stabilized to prevent further deterioration.
The ranch was evacuated under protest in 1942, when the Alamogordo Bombing and Gunnery Range took over the land to use in training World War II bombing crews. The house stood empty until the Manhattan Project support personnel arrived in early 1945.
Inside the house, 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 explosion, only two miles away, did not significantly damage the house. Most of the windows were blown out, but the main structure was intact. Years of rain water dripping through holes in the roof did much more damage. The barn did not do as well. During the Trinity test, the roof was bowed inward and some of the roofing was blown away. The roof has since collapsed.
The house stood empty and deteriorating until 1982, when the U.S. Army stabilized the house to prevent any further damage. Shortly after, the Department of Energy and U.S. Army provided the funds for the National Park Service to completely restore the house. The work was completed in 1984. All efforts were directed at making the house appear as it did on July 12, 1945.