A NATIONAL HISTORIC LANDMARK
WHITE SANDS MISSILE RANGE, NEW MEXICO
((COVER PHOTO shows Norris Bradbury, later director of Los Alamos, on the tower beside the "gadget" before the 1945 test.))
In deciding weather to visit ground zero at Trinity Site, the following information may prove helpful to you.
Radiation levels in the fenced, ground zero area are low. On average the levels are only 10 times greater than the region's natural background radiation. A ONE-HOUR VISIT TO THE INNER FENCED AREA WILL RESULT IN A WHOLE BODY EXPOSURE OF ONE-HALF TO ONE MILLIROENTGEN.
To put this in perspective, a U.S. adult receives and average exposure of 90 milliroentgens every year from natural and medical sources. For instance, the Department of Energy says we receive between 35 and 50 milliroentgens every year from the sun and from 20 to 35 milliroentgens every year from out food. Living in a brick house adds 50 millireontgens of exposure every year compared to living in a frame house. Finally, flying coast to coast in a jet airliner gives an exposure of between three and five milliroentgens on each trip.
Although radiation levels are low, some feel any extra exposure should be avoided. The decision is yours. It should be noted that small children and pregnant women are potentially more at risk than the rest of the population and are generally considered groups who should only receive exposure in conjunction with medical diagnosis and treatment. Again, the choice is yours.
At ground zero, Trinitite, the green, glassy substance found in the area, is still radioactive and must not be picked up.
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Trinity Site is where the first atomic bomb was tested at 5:29:45 a.m. Mountain War Time on July 16 1945. The 10 kiloton explosion not only led to a quick end to the war in the Pacific but also ushered the world into the atomic age. All life on Earth has been touched by the event wich took place here.
The 51,500-acre area was declared a national historic landmark in 1975. The landmark includes base camp, where the scientists and support group lived; ground zero, where the bomb was placed for the explosion; and the McDonald ranch house, where the plutonium core to the bomb was assembled. On you visit to Trinity Site you will be able to see ground zero and the McDonald ranch house. In addition, on your drive to the Trinity site area you will pass one of the old instrumentation bunkers wich is beside the road just west of ground zero.
The story of Trinity Site begins with the formation of the Manhattan Project in June 1942. The project was given overall responsibility of designing and building an atomic bomb. At the time it was a race to beat the Germans who, according to intelligence reports, were building their own atomic bomb.
Under the Manhattan Project three large facilities were constructed. At Oak Ridge, Tenn., huge gas diffusion and electromagnetic process plants were built to separate uranium 235 from its more common form, uranium 238. Hanford, Wash. became the home for nuclear reactors which produced a new element called plutonium. Both uranium 235 and plutonium are fissionable and can be used to produce and atomic explosion.
Los Alamos was established in northern New Mexico to design and build the bomb. At Los Alamos many of the greatest scientific minds of the day labored over the theory and actual construction of the device. The group was let by Dr. J. Robert Oppenheimer who is credited with being the driving force behind building a workable bomb by the end of the war.
Los Alamos scientists devised two designs for an atomic bomb--one using the uranium and another using the plutonium. The uranium bomb a simple design and scientist were confident it would work without testing. The Plutonium bomb worked by compressing the plutonium into a critical mass which sustains a chain reaction. The compression of the plutonium ball was to be
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In an atomic explosion, a chain reaction picks up speed as atoms split, releasing neutrons plus great amounts of energy. The escaping neutrons strike and split more atoms, thus releasing still more neutrons and energy. In a nuclear explosion this all occurs in a millionth of a second with billions of atoms being split.
Project leaders decided a test of the plutonium bomb was essential before it could be used as a weapon of war. from a list of eight sites in California, Texas, New Mexico and Colorado, Trinity Site was chosen as the test site. The area already was controlled by the government because it was part of the Alamogordo Bombing and Gunnery Range which was established in 1942. The secluded Jornado del Muerto was perfect as it provided isolation for secrecy and safety, but was still close to Los Alamos.
One of the first things you will see at the parking lot, which is south of ground zero, is the hulk of Jumbo. the bomb design to used at Trinity Site actually involved two explosions. First there would be a conventional explosion involving the TNT and then, a fraction of a second later, the nuclear explosion, if a chain reaction was maintained. The scientists were sure the TNT would explode, but were initially unsure of the plutonium. If the chain reaction failed to occur, the TNT would blow the very rare and dangerous plutonium all over the countryside.
Because of this possibility, Jumb was Designed and build in Ohio. Originally it was 25 feet long, 10 feet in diameter and weighed 214 tons. Scientists were planning to put the bomb in this huge steel jar because it could contain the TNT explosion if the chain reaction failed to materialize. This would prevent the plutonium from being lost. If the explosion occurred as planned, Jumbo would be vaporized.
Jumbo was brought to Pope, N.M., by rail and unloaded. A specially-built trailer with 64 wheels was used to move the trailer the 25 miles to Trinity Site.
As confidence in the plutonium bomb design grew it was decided not to use Jumbo. Instead, it was placed in a steel tower about 800 yards from ground zero. The blast destroyed the tower, but jumbo survived intact.
Today it rests at the entrance to ground zero so all can see it. Then ends are missing because of tests done later which involved trying to blow up Jumbo using TNT.
Ground zero, itself, is just a short walk to the north of the parking lot. A simple lava monument stands at ground zero and marks the spot where the 100-foot tower which held the bomb stood. The steel tower was anchored in
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The bomb was assembled under the tower on July 13. The Plutonium core was inserted into the device with some difficulty. On the first try it stuck. After letting the temperatures of the plutonium and casing equalize the core slid smoothly into place.
On July 14 the bomb was raised to the top of the tower. As the bomb was being lifted by a slow moving hoist nervous workers stopped the operation. They drove to base camp and brought back as many mattresses as they could find. When the bomb raising continued they placed mattresses under it just incase it fell. Once on top of the tower the bomb's detonators were installed. Meanwhile, other technicians went about installing seismographic and photographic equipment at varying distances from the tower. Other instruments were set up for recording radioactivity, temperature, air pressure and other data. Many instruments had been calibrated on May 27, 1945 when scientists exploded 100 tons of TNT on a 20-foot tower just south of ground zero.
Three observation points were established at 10,000 yards from ground zero. These were wooden shelters protected by concrete and earth. The south bunkers served as the control center for the test. The automatic firing device was triggered from there as key men such as Dr. Robert Oppenheimer, head of Los Alamos, watched. None of the manned bunkers are left.
Many scientists and support personnel, including Gen. Leslie Groves, head of the Manhattan Project, watched the explosion from base camp which was ten miles southwest of ground zero. All the buildings at the base camp were removed after the test. Most visiting VIPs watched from Compania Hill, 20 miles northwest of ground zero.
The test was scheduled for 4 a.m. July 16, but rain and lightning early that morning caused it to be postponed. The device could not be exploded under rainy conditions because rain and windw would increase the danger from radioactive fallout and interfere with observation of the test. At 4:45 a.m. the crucial weather report came through announcing calm to light winds with broken clouds for the following two hours.
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At 5:10 the countdown started and at 5:29:45 the device exploded successfully. To most observers the explosion--watched through dark glasses---overshadowed the shock wave and sound that arrived later.
Hans Bethe, one of the contributing scientists, wrote "it looked like a giant magnesium flare which kept on for what seemed a whole minute but was actually one or two seconds. The white ball grew and after a few seconds became clouded dust whipped up by the explosion from the ground and rose and left behind a black trail of dust particles."
Joe McKibben, another scientist, said, "We had a lot of flood lights on for taking movies of the control panel. When the bomb went off, the lights were drowned out by the big light coming in through the open door in the back."
Gen. Farrell, deputy go Gen. Groves, later wrote, "The effects could well be called unprecedented, magnificent, beautiful, stupendous and terrifying. No man-made phenomenon of such tremendous power had ever occurred before. The lighting effects beggared description. The whole country was lighted by a searing light with the intensity many times that of the midday sun."
Although no information on the test was released until after the atomic bomb was used as a weapon against Japan, people in New Mexico knew something had happened. The shock broke windows 120 miles away and was felt by many at least 160 miles away. Army officials simply stated that a munitions storage area had accidently exploded.
The explosion did not make much of a crater. Most eyewitnesses decribe the area as more of a small depression instead of a crater. The heat of the blast did melt the desert sand and turn it into a green glassy substance. It was called Trinitite and can still be seen in the area. At one time Trinitite completely covered the depression made by the explosion. Afterwards the depression was filled and much of hte Trinitite was taken away by the Nuclear Energy Commission.
To the west of the monument is a low structure which is protecting an original portion of the crater area. Windows are built into the shelter and some Trinitite is visible through them.
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The George McDonald ranch house site encompasses about three acres and consists of a house and various outbuildings. The house sits within an 85'x85' 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 1930's 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, 1,750 square-foot building. It is built of adobe which was plastered and painted. An ice house is located on the west side along with a 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 Aeromotor windmill east of the house. The scientists and support people used the north tank as a swimming pool during the long hot su er 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 abondoned in 1942 when the Alamorgordo 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 was designated the assembly room. Work benches 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 assembly room was used by scientists to put together the two hemispheres of plutonium, or P-239, and an initiator. According to reports, while the scientists assembled the initiator and P-239 hemispheres in the small room, jeeps were positioned outside the house for a possible quick getaway if problems arose. Detection devices were used to monitor radiation levels in the room as the core was assembled. The core created its own head and was warm to the touch. When the core was completed it was driven to ground zero where it was placed in the bomb assembly.
The explosion 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. Thr roof has since collapsed.
The house stood empty and deteriorating until 1982 when the U.S. Army stabilized teh 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 done in 1984. All efforts were directed at making the house appear as it did on July 12 1945.
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the story of what happened at the Trinity Site did not come to light unil after the second atomic bomb was exploded over Hiroshima, Japan, on August 6. President Truman made the announcement that day. Three days later, August 9, the third atomic bomb devastated the city of Nagasaki, and on August 14 the Japanese surrendered.
Trinity Site became part of what was then White Sands Proving Ground. The proving ground was established on July 9, 1945, as a test facility to investigate the new rocket technology emerging from World War II. The land, including Trinity Site and the old Alamogordo Bombing Range, came under the control of the new rocket and missile testing facility.
At first Trinity Site was encircled with a fence and radiation warning signs were posted. The site remained off-limits to military and civilian personnel of the proving ground and closed to the public.
By 1953 much of the radioactivity at trinity had subsided. In September about 650 people attended the first Trinity site open house. A few years later a small group from Tularosa visited the site on an anniversary of the explosion to conduct a religious service and prayers fro peace. Similar visits have been made annually in recent past years on the first Saturday in October. The visits are now made in April and October because it is generally so hot in July on the Jornana del Muerto.
White Sands Missile Range has developed from a simple desert testing site for the V-2 into one of the most sophisticated test facilities in the world. The mission of White Sands Missile Range begins with a customer -- a service developer, or another federal agency, which is ready to find out if engineers and scientists have built something which will perform according to job specifications. It ends when an exhaustive series of tests has been completed and a data report has been delivered to the customer.
Between the beginning and the end of the test program, be it Pershing or solar power, range employees are involved in every operation connected with the customer and his product. The range can and does provide everything from rat traps to telephones, from equipment hoists and flight safety to microsecond timing.
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In the end, it it's a missile, we fire it, record its performance and bring back the pieces for post mortem examination. All test data is reduced and the customer receives a full report
For more information on Trintiy Site or White Sands Missile Range contact:
Public Affairs Office (STEWS-PA)
White Sands Missile Range
White Sands Missile Range, N.M. 88002-5047
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1. Why is it called "trinity Site?"
The name is popularly attributed to Robert Oppenheimer, Director of Los Alamos. When the question of naming the site came up he was supposedly mulling over some John Donne poetry, specifically a devotional poem with the line, "Batter my heart, three person'd God...," and he directed Ken Bainbridge, the test director, to call it "Trinity." There are other versions. One is that the test at Trinity would be the culmination of the work of three facilities (a triad or trinity) created during World War II to build the bomb----Oak Ridge, Hanford and Los Alamos.
The green, glassy substance, Trinitite, which can still be found at Ground Zero takes it name from the site.
2. Are there any bunkers left?
There are three instrumentation bunkers left around the site. One is located just west of Ground Zero on the south side of the road coming into the site. Two more are located north of Ground Zero. All the manned bunkers were bulldozed and bruned decades ago.
3. What happened to the tower?
Within a millionth of a second the atomic explosion on the tower was generating temperatures exceeding those found on the sun. The Steel tower was vaporized (turned into gas) instantly. Only the footings buried under ground survived the intense heat. By the way, the bomb was not dropped from the tower---it was stationary on the platform when exploded.