Operation Sandstone
   HOME

TheInfoList



OR:

Operation Sandstone was a series of
nuclear weapon A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission or atomic bomb) or a combination of fission and fusion reactions (thermonuclear weapon), producing a nuclear exp ...
tests in 1948. It was the third series of American tests, following
Trinity The Trinity (, from 'threefold') is the Christian doctrine concerning the nature of God, which defines one God existing in three, , consubstantial divine persons: God the Father, God the Son (Jesus Christ) and God the Holy Spirit, thr ...
in 1945 and Crossroads in 1946, and preceding Ranger. Like the Crossroads tests, the Sandstone tests were carried out at the
Pacific Proving Grounds The Pacific Proving Grounds was the name given by the United States government to a number of sites in the Marshall Islands and a few other sites in the Pacific Ocean at which it conducted nuclear testing between 1946 and 1962. The U.S. tested ...
, although at
Enewetak Atoll Enewetak Atoll (; also spelled Eniwetok Atoll or sometimes Eniewetok; , , or , ; known to the Japanese as Brown Atoll or Brown Island; ) is a large coral atoll of 40 islands in the Pacific Ocean and with its 296 people (as of 2021) forms a leg ...
rather than
Bikini Atoll Bikini Atoll ( or ; Marshallese language, Marshallese: , , ), known as Eschscholtz Atoll between the 19th century and 1946, is a coral reef in the Marshall Islands consisting of 23 islands surrounding a central lagoon. The atoll is at the no ...
. They differed from Crossroads in that they were conducted by the Atomic Energy Commission, with the armed forces having only a supporting role. The purpose of the Sandstone tests was also different: they were primarily tests of new bomb designs, especially the more efficient levitated pits, rather than of the effects of nuclear weapons. Three tests were carried out in April and May 1948 by Joint Task Force 7, with a work force of 10,366 personnel, of whom 9,890 were military. The successful testing of the new cores in the Operation Sandstone tests rendered every component of the old weapons obsolete. Even before the third test had been carried out, production of the old cores was halted, and all effort concentrated on the new
Mark 4 nuclear bomb The Mark 4 nuclear bomb was an American implosion-type nuclear bomb based on the earlier Mark 3 Fat Man design, used in the Trinity test and the bombing of Nagasaki. With the Mark 3 needing each individual component to be hand-assembled by only ...
, which would become the first mass-produced nuclear weapon. More efficient use of fissionable material as a result of Operation Sandstone would increase the U.S. nuclear stockpile from 56 bombs in June 1948 to 169 in June 1949.


Origins

Nuclear weapon A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission or atomic bomb) or a combination of fission and fusion reactions (thermonuclear weapon), producing a nuclear exp ...
s were developed during
World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
by the
Manhattan Project The Manhattan Project was a research and development program undertaken during World War II to produce the first nuclear weapons. It was led by the United States in collaboration with the United Kingdom and Canada. From 1942 to 1946, the ...
, which created a network of production facilities, and the weapons research and design laboratory at the
Los Alamos National Laboratory Los Alamos National Laboratory (often shortened as Los Alamos and LANL) is one of the sixteen research and development Laboratory, laboratories of the United States Department of Energy National Laboratories, United States Department of Energy ...
. Two types of bombs were developed: the Mark 1
Little Boy Little Boy was a type of atomic bomb created by the Manhattan Project during World War II. The name is also often used to describe the specific bomb (L-11) used in the bombing of the Japanese city of Hiroshima by the Boeing B-29 Superfortress ...
, a
gun-type fission weapon Gun-type fission weapons are fission-based nuclear weapons whose design assembles their fissile material into a supercritical mass by the use of the "gun" method: shooting one piece of sub-critical material into another. Although this is someti ...
using
uranium-235 Uranium-235 ( or U-235) is an isotope of uranium making up about 0.72% of natural uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a nuclear chain reaction. It is the only fissile isotope that exists in nat ...
, and the Mark 3
Fat Man "Fat Man" (also known as Mark III) was the design of the nuclear weapon the United States used for seven of the first eight nuclear weapons ever detonated in history. It is also the most powerful design to ever be used in warfare. A Fat Man ...
, an
implosion-type nuclear weapon Nuclear weapons design are physical, chemical, and engineering arrangements that cause the physics package of a nuclear weapon to detonate. There are three existing basic design types: # Pure fission weapons are the simplest, least technically de ...
using
plutonium Plutonium is a chemical element; it has symbol Pu and atomic number 94. It is a silvery-gray actinide metal that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibits six allotropes and four ...
. These weapons were not far removed from their laboratory origins. A great deal of work remained to improve ease of assembly, safety, reliability and storage before they were ready for production. There were also many improvements to their performance that had been suggested or recommended during the war that had not been possible under the pressure of wartime development. Norris Bradbury, who replaced
Robert Oppenheimer J. Robert Oppenheimer (born Julius Robert Oppenheimer ; April 22, 1904 – February 18, 1967) was an American theoretical physicist who served as the director of the Manhattan Project's Los Alamos Laboratory during World War II. He is often ...
as director at Los Alamos, felt that "we had, to put it bluntly, lousy bombs." Plutonium was produced by irradiating
uranium-238 Uranium-238 ( or U-238) is the most common isotope of uranium found in nature, with a relative abundance of 99%. Unlike uranium-235, it is non-fissile, which means it cannot sustain a chain reaction in a thermal-neutron reactor. However, it i ...
in three 250 MW
nuclear reactors A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction. They are used for commercial electricity, marine propulsion, weapons production and research. Fissile nuclei (primarily uranium-235 or plutonium-2 ...
at the
Hanford site The Hanford Site is a decommissioned nuclear production complex operated by the United States federal government on the Columbia River in Benton County in the U.S. state of Washington. It has also been known as SiteW and the Hanford Nuclear R ...
. In theory they could produce of plutonium per megawatt-day, or about per month. In practice, production never approached such a level in 1945, when only between was produced per month. A Fat Man
core Core or cores may refer to: Science and technology * Core (anatomy), everything except the appendages * Core (laboratory), a highly specialized shared research resource * Core (manufacturing), used in casting and molding * Core (optical fiber ...
required about of plutonium, of which 21% fissioned. Plutonium production fell off during 1946 due to swelling of the reactors' graphite
neutron moderator In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, ideally without capturing any, leaving them as thermal neutrons with only minimal (thermal) kinetic energy. These thermal neutrons are immensely ...
s. This is known as the Wigner effect, after its discoverer, the Manhattan Project scientist
Eugene Wigner Eugene Paul Wigner (, ; November 17, 1902 – January 1, 1995) was a Hungarian-American theoretical physicist who also contributed to mathematical physics. He received the Nobel Prize in Physics in 1963 "for his contributions to the theory of th ...
. These reactors were also required for the production (by irradiation of
bismuth-209 Bismuth-209 (Bi) is an isotope of bismuth, with the longest known half-life of any radioisotope that undergoes α-decay (alpha decay). It has 83 protons and a magic number of 126 neutrons, and an atomic mass of 208.9803987 amu (atomic mass unit ...
) of
polonium-210 Polonium-210 (210Po, Po-210, historically radium F) is an isotope of polonium. It undergoes alpha decay to stable 206Pb with a half-life of 138.376 days (about months), the longest half-life of all naturally occurring polonium isotopes (210– ...
, which was used in the initiators, a critical component of the nuclear weapons. Some of bismuth-209 had to be irradiated for 100 days to produce 600 curies of polonium-210, a little over . Because polonium-210 has a half-life of only 138 days, at least one reactor had to be kept running. The oldest unit, B pile, was therefore closed down so that it would be available in the future. Investigation of the problem would take most of 1946 before a fix was found.
Uranium-235 Uranium-235 ( or U-235) is an isotope of uranium making up about 0.72% of natural uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a nuclear chain reaction. It is the only fissile isotope that exists in nat ...
was derived from enrichment of natural uranium at the
Y-12 plant The Y-12 National Security Complex is a United States Department of Energy National Nuclear Security Administration facility located in Oak Ridge, Tennessee, near the Oak Ridge National Laboratory. It was built as part of the Manhattan Project ...
and K-25 site in Oak Ridge, Tennessee. Improvements in the processes and procedures of the
electromagnetic In physics, electromagnetism is an interaction that occurs between particles with electric charge via electromagnetic fields. The electromagnetic force is one of the four fundamental forces of nature. It is the dominant force in the interacti ...
and gaseous isotope separation between October 1945 and June 1946 led to an increase in production to around of uranium-235 per month, which was only enough for one of the very wasteful Little Boys. A Fat Man was 17.5 times as efficient as a Little Boy, but a ton of uranium ore could yield eight times as much uranium-235 as plutonium, and on a per-gram basis, plutonium cost somewhere between four and eight times as much to produce as uranium-235, which at this time cost around $26 per gram.


Weapon development 1945–1948

The objectives of the Sandstone series of tests were to: # test nuclear cores and initiators; # improve the theory and knowledge of implosion type weapons; # test levitated cores; # test composite cores; and # determine the most economic designs in terms of efficient use of fissionable material. Levitation meant that instead of being immediately inside the tamper, there would be an air gap between the tamper and the core, which would be suspended inside on wires. This would allow the tamper to gain more momentum before striking the core. The principle was similar to swinging a hammer at a nail versus putting the hammerhead directly on the nail and pushing as hard as possible. In order for this to work outside the laboratory, the wires had to be strong enough to withstand being dropped from an aircraft, but thin enough to not disturb the spherical symmetry of the implosion. The Theoretical Division at Los Alamos, known as T Division, had run computer calculations on the levitated core as early as March 1945. The use of the levitated core had been proposed during the planning for Operation Crossroads, but it had been decided instead to use the existing solid core "Christy" design. This was named after its designer, Robert Christy. For Sandstone, however, it was decided that at least two of the three tests would use levitated cores. The motivation behind the composite core was to make better use of the available fissionable material. The use of uranium-235 in an implosion weapon instead of the inefficient gun type Little Boy was an obvious development. However, while plutonium was more expensive and harder to produce than uranium-235, it fissions faster, because it makes better use of the neutrons its fission produces. On the other hand, the slower reaction of uranium-235 permits the assembly of super-critical masses, making it theoretically possible to produce weapons with high yields. By July 1945, Oppenheimer and Groves were considering using both materials in a composite core containing of plutonium and of uranium-235. The composite cores became available in 1946. Los Alamos' priority then became the development of an all-uranium-235 core. By January 1948 the national stockpile contained 50 cores, of which 36 were composite Christy cores, nine were plutonium Christy cores, and five were composite levitated cores. Testing the new levitated, composite and uranium-235 cores would require at least three test firings. More efficient weapons would require less efficient initiators. This meant that less polonium would be required. At the time of Sandstone, the national stockpile of polonium-beryllium initiators consisted of 50 A-Class initiators, with more than 25 curies of polonium, and 13 B-Class initiators with 12 to 25 curies. During Sandstone, at least one test would be conducted with a B-Class initiator.


Preparations


Organization

The tests were authorized by
President President most commonly refers to: *President (corporate title) * President (education), a leader of a college or university *President (government title) President may also refer to: Arts and entertainment Film and television *'' Præsident ...
Harry S. Truman Harry S. Truman (May 8, 1884December 26, 1972) was the 33rd president of the United States, serving from 1945 to 1953. As the 34th vice president in 1945, he assumed the presidency upon the death of Franklin D. Roosevelt that year. Subsequen ...
on June 27, 1947. The Atomic Energy Commission's Director of Military Applications, Brigadier General
James McCormack James McCormack Jr. (8 November 1910 – 3 January 1975) was a United States Army officer who served in World War II, and was later the first Director of Military Applications of the United States Atomic Energy Commission. A 1932 graduate of t ...
and his deputy,
Captain Captain is a title, an appellative for the commanding officer of a military unit; the supreme leader or highest rank officer of a navy ship, merchant ship, aeroplane, spacecraft, or other vessel; or the commander of a port, fire or police depa ...
James S. Russell, met with Bradbury and John Henry Manley at Los Alamos on July 9 to make arrangements for the tests. They readily agreed that they would be scientific in nature, with Los Alamos supplying the technical direction and the armed forces providing supplies and logistical support. The cost of the tests, around $20 million, was divided between the Department of Defense and the Atomic Energy Commission.
Lieutenant General Lieutenant general (Lt Gen, LTG and similar) is a military rank used in many countries. The rank traces its origins to the Middle Ages, where the title of lieutenant general was held by the second-in-command on the battlefield, who was norma ...
John E. Hull John Edwin Hull (26 May 1895 – 10 June 1975) was a United States Army general, former Vice Chief of Staff of the United States Army, commanded Far East Command (United States), Far East Command from 1953 to 1955 and the U.S. Army, Pacific from ...
was designated as test commander. Rear Admiral William S. Parsons and Major General William E. Kepner reprised their Operation Crossroads roles as deputy commanders. Joint Task Force 7 was formally activated on October 18, 1947. As its commander, Hull was answerable to both the
Joint Chiefs of Staff The Joint Chiefs of Staff (JCS) is the body of the most senior uniformed leaders within the United States Department of Defense, which advises the president of the United States, the secretary of defense, the Homeland Security Council and ...
and the Atomic Energy Commission. Joint Task Force 7 consisted of 10,366 personnel, 9,890 of them military. Its headquarters consisted of about 175 men, of whom 96 were on board the . The rest were accommodated on the , and . A special division of the Los Alamos National Laboratory, known as J Division, was created specifically to manage nuclear testing. An Atomic Energy Commission group (Task Group 7.1) was responsible for preparing and detonating the nuclear weapons, and conducting the experiments. It consisted of some 283 scientists and technicians responsible for nuclear tests from J Division, the
Armed Forces Special Weapons Project The Armed Forces Special Weapons Project (AFSWP) was a United States military agency responsible for those aspects of nuclear weapons remaining under military control after the Manhattan Project was succeeded by the Atomic Energy Commission on ...
, the
Naval Research Laboratory The United States Naval Research Laboratory (NRL) is the corporate research laboratory for the United States Navy and the United States Marine Corps. Located in Washington, DC, it was founded in 1923 and conducts basic scientific research, appl ...
, the
Naval Ordnance Laboratory The Naval Ordnance Laboratory (NOL) was a facility in the White Oak, Maryland, White Oak area of Montgomery County, Maryland. The location is now used as the headquarters of the Food and Drug Administration, U.S. Food and Drug Administration. Or ...
,
Argonne National Laboratory Argonne National Laboratory is a Federally funded research and development centers, federally funded research and development center in Lemont, Illinois, Lemont, Illinois, United States. Founded in 1946, the laboratory is owned by the United Sta ...
, the
Aberdeen Proving Ground Aberdeen Proving Ground (APG) is a U.S. Army facility located adjacent to Aberdeen, Harford County, Maryland, United States. More than 7,500 civilians and 5,000 military personnel work at APG. There are 11 major commands among the tenant units, ...
, the Atomic Energy Commission, Edgerton, Germeshausen & Grier, and other agencies. Each dealt with a different aspect of the tests. The Naval Ordnance Laboratory handled the blast measurement tests, while the Naval Research Laboratory conducted the radiation measurement experiments, and Argonne National Laboratory did
gamma ray A gamma ray, also known as gamma radiation (symbol ), is a penetrating form of electromagnetic radiation arising from high energy interactions like the radioactive decay of atomic nuclei or astronomical events like solar flares. It consists o ...
measurements. Edgerton, Germeshausen, and Grier were contractors hired to design and install the timing and firing systems. Seven experimental weapon assemblies and six cores were delivered to
San Pedro, California San Pedro ( ; ) is a neighborhood located within the South Bay (Los Angeles County), South Bay and Los Angeles Harbor Region, Harbor region of the city of Los Angeles, California, United States. Formerly a separate city, it consolidated with Los ...
, and loaded on the weapon assembly ship , in February 1948, but the Atomic Energy Commission only gave permission for the expenditure of three cores in the tests.


Ships

The naval forces were organized as Task Group 7.3. It consisted of: ;Task Unit 7.3.1 * (flagship) ;Task Unit 7.3.2 Main Naval Task Unit * * * * * * USS ''LST-45'' * USS ''LST-219'' * USS ''LST-611'' ; Task Unit 7.3.3 Offshore Patrol * * * * * * * * * ; Task Unit 7.3.4 Helicopter Unit * – 4 HO3S and 2 HTL helicopters ; Task Unit 7.3.5 Services Unit * * * USS ''YOG-64'' * USS ''YW-94'' ;Task Unit 7.3.6 Cable Unit * USS ''LSM-250'' * USS ''LSM-378'' * Naval Signal Unit No. 1 ; Task Unit 7.3.7 Boat Pool Unit * * * USS ''LCI-549'' * USS ''LCI(L)-1054'' * USS ''LCI(L)-1090'' * USS ''LCI-472'' * USS ''LCI-494'' * USS ''LCI-l194'' * USS ''LCI-1345'' Source: Berkhouse ''et al'', ''Operation Sandstone'', p. 40


Civil affairs

In September 1947, Hull, Russell, who was designated test director on October 14, and Joint Task Force 7's scientific director, Darol K. Froman from the Los Alamos Laboratories, set out with a group of scientists and military officers to examine various proposed test sites in the Pacific. Enewetak Atoll was chosen as the test site on October 11. The island was remote, but with a good harbor and an airstrip. It also had ocean currents and trade winds that would carry fallout out to sea, an important consideration in view of what had happened at
Bikini Atoll Bikini Atoll ( or ; Marshallese language, Marshallese: , , ), known as Eschscholtz Atoll between the 19th century and 1946, is a coral reef in the Marshall Islands consisting of 23 islands surrounding a central lagoon. The atoll is at the no ...
during Operation Crossroads. As the
Trust Territory of the Pacific Islands The Trust Territory of the Pacific Islands (TTPI) was a United Nations trust territory in Micronesia administered by the United States from 1947 to 1994. The Imperial Japanese South Seas Mandate had been seized by the U.S. during the Pacifi ...
was a United Nations trust territory administered by the United States, the
United Nations Security Council The United Nations Security Council (UNSC) is one of the six principal organs of the United Nations (UN) and is charged with ensuring international peace and security, recommending the admission of new UN members to the General Assembly, an ...
was notified of the upcoming tests on December 2. The atoll was inhabited by the dri-Enewetak, who lived on Aomon, and the dri-Enjebi, who lived on Bijire. Their original homes had been on Enewetak and Enjebi, but they had been moved during the war to make way for military bases. The population, about 140 in number, had been temporarily relocated to Meck Island during Operation Crossroads. This time,
Ujelang Atoll Ujelang Atoll ( Marshallese: , ) is an uninhabited coral atoll of 30 islands in the Pacific Ocean, in the Ralik Chain of the Marshall Islands. Its total land area is , and it encloses a lagoon of . It is the westernmost island in the Marshall I ...
, an uninhabited atoll southwest of Enewetak, was selected as a relocation site. A Naval Construction Battalion group arrived there on November 22 to build accommodation and amenities. The military authorities met with the local chiefs on December 3, and they agreed to the relocation, which was carried out by by December 20. An LST and four
Douglas C-54 Skymaster The Douglas C-54 Skymaster is a four-engined transport aircraft used by the United States Army Air Forces in World War II and the Korean War. Like the Douglas C-47 Skytrain derived from the DC-3, the C-54 Skymaster was derived from a civilia ...
aircraft were placed on standby to evacuate Ujelan in case it was affected by fallout, but were not required. In January 1948, General William E. Kepner and the Joint Chiefs officially authorized the incorporation of a Long-Range Detection (LRD) element into the Sandstone tests, designating it as Operation Fitzwilliam. This top-secret initiative aimed to establish techniques for identifying nuclear explosions worldwide. The operation remained classified for decades and was not declassified until 2014.Operation Fitzwilliam Report Vol. 1
/ref> Unlike the Crossroads tests, which were conducted in the media spotlight, the Sandstone tests were carried out with minimal publicity. On April 15, there was still discussion in Washington about whether or not there should be any public announcement of the tests at all. Hull opposed making any announcement until after the series was completed, but the AEC commissioners felt that the news would leak out, and the United States would look secretive. It was therefore decided to make a last minute announcement. There was no announcement of the purpose of the tests, and only cursory press releases. On 18 May, after the series was over, Hull held a press conference in Hawaii, but only permitted the media to quote from written statements.


Construction

Enjebi, Aomon, and Runit Islands were cleared of vegetation and graded level to make it easier to install the required instrumentation, and a causeway was built between Aomon and Bijire so the instrument cables could be run from the test tower on Aomon to the control station on Bijire. The detonations were ordered so that later test areas would suffer minimal fallout from the earlier shots. The Army component, Task Group 7.2, was responsible for construction work. It consisted of the 1220th Provisional Engineer Battalion, with the 1217th and 1218th Composite Service Platoons, the 18th Engineer Construction Company and 1219th Signal Service Platoon; Companies D and E of the 2nd Engineer Special Brigade's 532nd Engineer Boat and Shore Regiment; the 461st Transportation Amphibious Truck Company; 854th Transportation Port Company; 401st CIC Detachment; and the Naval Shore Base Detachment.


Operations

As in Operation Crossroads, each detonation was given its own code name, taken from the
Joint Army/Navy Phonetic Alphabet The Allied military phonetic spelling alphabets prescribed the words that are used to represent each letter of the alphabet, when spelling other words out loud, letter-by-letter, and how the spelling words should be pronounced for use by the All ...
. All used modified Mark III assemblies, and were detonated from towers. The timing of the detonations was a matter of compromise. The
gamma ray A gamma ray, also known as gamma radiation (symbol ), is a penetrating form of electromagnetic radiation arising from high energy interactions like the radioactive decay of atomic nuclei or astronomical events like solar flares. It consists o ...
measurement experiments required darkness, but the
Boeing B-17 Flying Fortress The Boeing B-17 Flying Fortress is an American four-engined heavy bomber aircraft developed in the 1930s for the United States Army Air Corps (USAAC). A fast and high-flying bomber, the B-17 dropped more bombs than any other aircraft during ...
drones that would sample the clouds needed daylight to control them. As a compromise, the Sandstone detonations all took place shortly before dawn. The detonations in the United States' Sandstone series are listed below:


X-Ray

The X-Ray nuclear device used a levitated composite core. It was detonated on Enjebi just before sunrise at 06:17 on April 15, 1948, with a yield of 37 kilotons. The efficiency of utilization of the plutonium was about 35%; that of the uranium-235 was 25% or more. This was somewhat higher than Los Alamos' prediction. Observers watching from ships in the lagoon saw a brilliant flash and felt the radiant heat. A condensation cloud in diameter quickly enveloped the fireball, which glowed within the cloud. It took 45 to 50 seconds for the thunderous roar of the explosion to reach the observers. About 20 minutes later, ''Bairoko'' launched a helicopter to check on the cable winch which was to collect samples. It also lowered boats to test radioactivity levels in the lagoon. B-17 pilotless drone aircraft were flown through the clouds, and a drone light tank was used to recover soil samples from the crater. Unfortunately, it became bogged and had to be towed out ten days later.


Yoke

The Yoke nuclear device used a levitated all-uranium-235 core. It was detonated on Aomon just before sunrise on May 1, 1948, at 06:09, a day late due to unfavorable winds. The observers saw a similar flash and felt the same heat as the X-Ray blast, but the wide condensation cloud was larger, and the sound of the explosion more forceful. One observer likened it to the sound of "a paper bag which is forcefully burst in a small room". They were correct: its yield of 49 kilotons made it the largest nuclear detonation up to that time, but it was considered inefficient and wasteful of the fissile material.


Zebra

Zebra, the third test, and the last of the Sandstone series, was detonated on Runit just before sunrise at 06:04 on May 15, 1948. This test was characterized by AEC Chairman David Lilienthal as the "hardest and most important" test of the three. By using one of the B-class initiators, it demonstrated that these could still be used with confidence. The observers perceived the flash and blast as similar to the previous two tests, but this time the base of the condensation cloud was at , which gave the observers an unobstructed view of the fireball, which therefore appeared to be brighter and last longer than the other two. Looks were deceiving: its levitated uranium-235 core produced a yield of 18 kilotons. The procedures used in the previous tests were repeated, but this time the winch cable snagged, and the test samples had to be retrieved by a jeep, exposing its crew to more radiation. The Los Alamos personnel assigned to remove the filters from the B-17 drones had apparently carried out the procedure on X-Ray and Yoke without problems, but this time three of them suffered radiation burns on their hands serious enough to be hospitalized and need
skin grafting Skin grafting, a type of graft surgery, involves the transplantation of skin without a defined circulation. The transplanted tissue is called a skin graft. Surgeons may use skin grafting to treat: * extensive wounding or trauma * burns * ...
. One of the men who had carried out the procedure for Yoke was then also found to have burns on his hands and was hospitalized too, but was discharged on 28 May. Once again the drone tank gave trouble, and bogged in the crater, but the soil samples were retrieved by the backup drone tank. Both tanks were subsequently dumped in the ocean.


Outcome

The successful testing of the new cores in the Sandstone tests had a profound effect. Practically every component of the old weapons was rendered obsolete. Even before the third test had been carried out, Bradbury had halted production of the old cores, and ordered that all effort was to be concentrated on the
Mark 4 nuclear bomb The Mark 4 nuclear bomb was an American implosion-type nuclear bomb based on the earlier Mark 3 Fat Man design, used in the Trinity test and the bombing of Nagasaki. With the Mark 3 needing each individual component to be hand-assembled by only ...
, which would become the first mass-produced nuclear weapon. The more efficient use of fissionable material would increase the nuclear stockpile from 56 bombs in June 1948 to 169 in June 1949. The Mark III bombs were withdrawn from service in 1950. At the same time, new production plants were coming online and the Wigner effect problem had been solved. By May 1951, plutonium production was twelve times that of 1947, while uranium-235 production had increased eight-fold. The Chief of the
Armed Forces Special Weapons Project The Armed Forces Special Weapons Project (AFSWP) was a United States military agency responsible for those aspects of nuclear weapons remaining under military control after the Manhattan Project was succeeded by the Atomic Energy Commission on ...
, Major General Kenneth D. Nichols, saw clearly that the era of scarcity was over. He now "recommended that we should be thinking in terms of thousands of weapons rather than hundreds."


Notes


References

* * * * * * * *


External links

* * * * * * {{Authority control Explosions in 1948
Sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...
1948 in military history 1948 in the environment 1940s in the Marshall Islands 1948 in the Trust Territory of the Pacific Islands April 1948 in Oceania May 1948 in Oceania April 1948 in the United States May 1948 in the United States Articles containing video clips